University of California
California Fish Website

California Fish Species

Amargosa Pupfish

Scientific Name
Cyprinodon nevadensis
Native
Native Species
Identification

Amargosa pupfish, left side. Photographed at Ash Meadows, Nevada in April 2006. Photo by Joseph C. Sullivan.
Amargosa pupfish, left side. Photographed at Ash Meadows, Nevada in April 2006. Photo by Joseph C. Sullivan.

Amargosa pupfish, right side. Photographed at Ash Meadows, Nevada in April 2006. Photo by Joseph C. Sullivan.
Amargosa pupfish, right side. Photographed at Ash Meadows, Nevada in April 2006. Photo by Joseph C. Sullivan.

Amargosa pupfish, dorsal/frontal view. Photographed at Ash Meadows, Nevada in April 2006. Photo by Joseph C. Sullivan.
Amargosa pupfish, dorsal/frontal view. Photographed at Ash Meadows, Nevada in April 2006. Photo by Joseph C. Sullivan.

  • Small, usually less than 50 mm TL
  • Blunt head, deep body (especially in reproductive males)
  • Small and oblique terminal mouth, complete row of tricuspid teeth; central cusps truncated or pointed
  • Large scales, spines absent from circuli; interspaces reticulated
  • Pelvic fins small or absent, preopercular pores: 7-17
  • Coloration:
  • Breeding males: bright blue sides and causal peduncle, black band on edge of tail
  • Breeding females: olive brown, ocellus usually present on posterior base of dorsal fin, 6-10 lateral vertical bars (may be faint)
  • Fin rays: anal 8-11, pectoral 11-18, pelvic 0-9, caudal 14-22
  • Lateral line scales: 23-28
Life History

Amargosa pupfish inhabit several isolated springs and reaches of stream that are all different in relation to habitat and water quality characteristics. In Ash Meadows, Nye County, Nevada, pupfish live in multiple springs with temperatures ranging from 21-33°C, though within each spring the annual fluctuations are only 2-7°C. The meadow springs are typically shallow ( Lining the edges of most of these springs are emergent cattails. In the saline Amargosa River, pupfish deal with daily changes of 15-20°C and annual fluctuations from near freezing up to 40°C. In Tecopa Bore, Inyo County, Amargosa pupfish inhabit an outflow from an artesian well that is linked to the Amargosa River. The water entering the marsh is 47.5°C and within this section pupfish survive and favor a water temperature of 42°C. During winter months the downstream end of the marsh may reach temperatures near freezing. Downstream of Tecopa on the Amargosa River is a steep and narrow canyon. The stream is less than 2 m wide and reaches depths up to 2.5 m. The water is clear, saline, and alkaline. The TDS ranges from 1,390-3,890 ppm and the dissolved oxygen levels range from 7.3-11.6 mg/L. The canyon stretch of the Amargosa River alternates from soft mud and clay pools to gravel and sand filled runs. The shores are often lined with vegetation. The Amargosa River eventually flows into Death Valley where the soft substrate is made up of small (silt, clay, sand) particles and where algae and cyanobacteria are present. The water here has a salinity ranging from 3-18 ppt depending upon the season. Water temperatures vary from 10-38°C annually though they may drop to near zero in severe winters. Another place with interesting pupfish habitat is Saratoga Springs. Pupfish inhabit the large spring pool as well as the series of lakes connected to the spring. Pupfish in the lakes favor habitat with adequate aquatic vegetation and favor water temperatures in the range of 20-30°C. Amargosa pupfish in the Saratoga Springs drainage avoid water where the temperature exceeds 38°C and in cool months the pupfish bury themselves in the substrate. Amargosa pupfish are diurnal feeders with a diet composed of mostly algae and cyanobacteria. They may also feed on small invertebrates such as chironomid larvae, ostracods, copepods, and mosquito larvae. Generally they grow rapidly, though growth rates decrease in rapidly fluctuating environments. They rarely live longer than a year, and most pupfish reach sexual maturity and a length of 25-30 mm TL in several months. Spawning by Amargosa pupfish varies among locations. In spring environments Amargosa pupfish have similar behavior to Owens pupfish in that males defend territories and go through a courtship ritual with females. In the Amargosa River, spawning occurs in groups with males targeting a female among the crowd.

Links to Other Research
Watershed
  • Death Valley-Lower Amargosa Watershed
  • Upper Amargosa Watershed

American Shad

Scientific Name
Alosa sapidissima
Native
Non-Native
Identification

American shad, head. Caught on the Feather River (Star Bend boat launch) on 4 July 2008. Approximately 20 cm TL. Note the mouth, which is much larger than that of a threadfin shad. Photo courtesy of Brian Currier.
American shad, head. Caught on the Feather River (Star Bend boat launch) on 4 July 2008. Approximately 20 cm TL. Note the mouth, which is much larger than that of a threadfin shad. Photo courtesy of Brian Currier.

American shad, habitat. Feather River (Star Bend boat launch), 4 July 2008. Photo courtesy of Brian Currier.
American shad, habitat. Feather River (Star Bend boat launch), 4 July 2008. Photo courtesy of Brian Currier.

  • Large, compressed body with a sawtooth keel
  • Thin, deciduous scales
  • Terminal mouth with equal length jaws
  • Dorsal fin is short and straight edged (15-19 rays)
  • 18-24 anal fin rays
  • 50-55 Lateral line scales but the lateral line is poorly developed
  • 19-23 belly scutes before pelvic fin base and 12-19 behind
  • Steely blue on top and silvery on the sides
  • A row of 4-6 black dots starting with the largest above the operculum and extending back laterally
Life History

American shad are an anadromous fish and only appear infreshwater during their first 2 years of life and when they return to spawn as adults. Their life at sea is poorly understood but their ability to return to their original spawning ground is known to be exceptional. In the fall, mature shad (3-4 years old for males and 4-5 years old for females) return to estuaries where their bodies transition to the fresh water environment. Runs up river to spawn begin with un-ripe males in March and April when water temperatures reach 14°C, and peak in late May and early June when the water is between 17°C and 24°C. By the first week of July most spawning is complete. Spawning occurs in the main channels of the river where the flow is between 31 and 91 cm/s, dissolved oxygen is greater than 5 mg/L, and the water depth is anywhere between 1 and 10 m, but usually under 3 m. Sand or gravel bottoms are preferred but a variety of substrates can be used.  Mating happens most often after dark and consists of one or more males pressing up against a female as they swim in a tight circle releasing sperm and eggs.  This will happen multiple times until the female has released all of her eggs. Fecundity levels for California rivers have not been recorded but females in New York populations will lay between 116,000 and 468,000 eggs a season with an average of approximately 250,000.

Embryos float with the current downstream before hatching 3-12 days later depending on water temperature. An American shad larva is between 6 and 10 mm in length when it hatches and will quickly grow to between 9 and 12 mm when they absorb their yolk sac. At this point it is very important for the young to reach a food rich area because larvae that have not eaten within 2 days of birth have a severely diminished chance of survival. Their diet consists mainly of zooplankton such as mysid shrimp, but young American shad will also eat surface insects and bottom dwelling organisms, like midge larvae, if the opportunity arises. Returning adults can eat the same prey but are so focused on spawning when they reach the river that they often ignore food entirely. Shad will remain freshwater fish until they metamorphose out of their larval stage approximately 4 weeks after hatching. After this transformation they become resistant to salinities up to 20 ppt. Young American shad usually leave their rivers of birth sometime between September and November but if it is a particularly wet year and overflows are high they may leave as early as June. Some stay in estuaries for 1-2 years before heading to open waters but the majority of American shad head directly to the sea. Shad are usually between 5 and 15 cm by the time they leave the river and by the end of their first year will be, on average, 8 cm long. Males will add approximately 8 cm each year after that until their 5th year when growth slows down. Females grow more rapidly and will reach 42 cm by their 3rd year as opposed to the males’ average of 24 cm. Females’ growth rates level off after this but they will still be, on average, 6 cm longer than males by the time they reach the maximum age of 7.

A unique group of American shad is found in Millerton Lake near Fresno where the population is entirely land-locked. Mature shad appear in the San Joaquin River in late April and spawning peaks in mid June through July but can continue as late as September. Millerton shad prefer to spawn in slower water (20-60 cm/s) and will mate only between the hours of 9 pm and 7 am. Millerton shad growth is also slightly slower for females making the rates of growth between the sexes more equal.

Links to Other Research
Watershed

Arroyo Chub

Scientific Name
Gila orcutti
Native
Native Species
Identification

Arroyo chub. Captured from San Antonio Creek (Vandenberg Air Force Base) in 2008. Photo by Carl Page, ARS Consulting.
Arroyo chub. Captured from San Antonio Creek (Vandenberg Air Force Base) in 2008. Photo by Carl Page, ARS Consulting.

  • Small chunky fish, up to 120 mm SL
  • Deep body and caudal peduncle
  • Large eyes, short round snout, small sub-terminal mouth
  • Coloration: body is silver or gray to olive green on top, white underside, and dull gray lateral band
  • Males have larger fins than females
  • Breeding males develop patch of tubercles on upper surface of pectoral fins
  • Fin rays: dorsal 8, anal 7
  • Lateral line scales: 48-62
  • Gill rakers: 5-9
  • Pharyngeal teeth: typically 2,5-4,2
Life History

 

Arroyo chub are native to the streams and rivers of the Los Angeles plain in southern California, including the Los Angeles, San Gabriel, San Luis Rey, Santa Ana, and Santa Margarita Rivers, and Malibu and San Juan Creeks. They have been extirpated from much of their native range, but have been introduced to streams along the coast as far north as Chorro Creek in San Luis Obispo County. They have also been introduced to the Mojave River system where they have eliminated the Mojave tui chub. Arroyo chub are adapted to survive in cool to warm (10 – 24oC) streams that fluctuate between large winter storm flows, and low summer flows, and the low dissolved oxygen and wide temperature fluctuations associated with this flow regime. They are most common in slow flowing or backwater areas with sand or mud substrate, but may also inhabit areas with velocities in excess of 80 cm/s over coarse substrate. They feed on plants such as algae and water fern (Azolla), and on invertebrates such as insects and mollusks. Arroyo chubs reach a size of 80 - 90 mm by their fourth year and rarely live longer than this. Females can reproduce at age 1. Spawning takes place in pools and edge habitat from February to August with a peak in June and July. Several males may fertilize the eggs of one female. Fertilized eggs stick to plants or bottom substrate and hatch in about 4 days. Fry stay on the substrate for a few days, then rise to the surface and stay among plants or other cover for 3 – 4 months.

Links to Other Research
Watershed
  • Aliso-San Onofre Watershed
  • Antelope-Fremont Valleys Watershed
  • Calleguas Watershed
  • Central Coastal Watershed
  • Cuyama Watershed
  • Los Angeles Watershed
  • Mojave Watershed
  • Newport Bay Watershed
  • San Antonio Watershed
  • San Diego Watershed
  • San Gabriel Watershed
  • San Jacinto Watershed
  • San Luis Rey-Escondido Watershed
  • Santa Ana Watershed
  • Santa Barbara Coastal Watershed
  • Santa Clara Watershed
  • Santa Margarita Watershed
  • Santa Maria Watershed
  • Santa Monica Bay Watershed
  • Santa Ynez Watershed
  • Seal Beach Watershed
  • Southern Mojave Watershed
  • Ventura Watershed

Bigscale Logperch

Scientific Name
Percina macrolepida
Native
Non-Native
Identification

Bigscale logperch, captured from Putah Creek in November 2008. Photo by Teejay O'Rear, March 2009.
Bigscale logperch, captured from Putah Creek in November 2008. Photo by Teejay O'Rear, March 2009.

Bigscale logperch, anterior. Captured from Putah Creek in November 2008. Photo by Teejay O'Rear, March 2009.
Bigscale logperch, anterior. Captured from Putah Creek in November 2008. Photo by Teejay O'Rear, March 2009.

Bigscale logperch, dorsal fins. Captured from Putah Creek in November 2008. Photo by Teejay O'Rear, March 2009.
Bigscale logperch, dorsal fins. Captured from Putah Creek in November 2008. Photo by Teejay O'Rear, March 2009.

  • Long, slender, tubular bodies
  • Pointed, projecting snouts
  • Ctenoid scales cover breast, cheeks, operculars, and nape
  • Row of large spiny scales on the belly
  • 77-90 scales on lateral line
  • Yellowish with 14-16 complete, dark, vertical stripes and a dark spot at the base of the tail
  • Darker heads and orange bars on dorsal fins indicate a breeding male
  • 2 small, well separated dorsal fins (13-15 spines, and 12-15 fin rays on the first and second fin respectively)
  • Enlarged, fan-like pectoral fins with 12-14 fin rays
  • 2 spines and 7-10 fin rays on anal fin
  • 1 spine and 5 fin rays on the pelvic fins
Life History

 

Bigscale logperch can be found in a variety of habitats including the slow moving sections of warm, clear streams and the shallow areas of reservoirs with bottoms covered in mud, gravel, rock, and other debris. They have also been found in estuaries with salinities up to 4.2 ppt and the turbid waters of mud bottomed sloughs and ditches.  In many of these areas they are often found at the edge of emergent vegetation. Here they bury themselves in the bottom and lay nearly motionless allowing their coloration to act as camouflage from predators. It also allows them to ambush any unsuspecting prey that may float by. More commonly, however, they will prowl close to the bottom, overturning debris with their snout and using their eyesight to catch a variety of invertebrates. Insect larvae are the most common prey but the bigscale logperch is a very opportunistic species and different populations will have very different diets depending on what is available. Schooling and territorial behavior is rare with the most social activity happening during the breeding season.

Maturity is reached in their second year and spawning occurs between February and mid-July. Mating consists of a unique ritual in which the female will stand on her tail to attract the male before the pair presses against each other in a vertical position. Once the ritual is complete the female lays 150-400 eggs onto the leaves of an aquatic plant or into a small gravel pit. Larvae are pelagic when hatched and will float downstream until they enter a side channel to rear. Young bigscale logperch will reach 48-81 mm in their first year and 75-102 mm in the second.

 

Links to Other Research
Watershed

Black Bullhead

Scientific Name
Ameiurus melas
Native
Non-Native
Identification

Black bullhead, approximately 15 cm (6”) long. Location: Suisun Marsh, California Date: 8/6/2007
Black bullhead, approximately 15 cm (6”) long. Location: Suisun Marsh, California Date: 8/6/2007

Black bullhead, approximately 15 cm (6”) long. Location: Suisun Marsh, California Date: 8/6/2007
Black bullhead, approximately 15 cm (6”) long. Location: Suisun Marsh, California Date: 8/6/2007

  • Stout body
  • Dark chin barbels
  • Dark on top and pale on the belly with a pale vertical bar at the base of the caudal fin
  • Adults have a golden-yellow belly while the juveniles have a white belly
  • Square tipped, slightly notched tail
  • Short, round anal fin with dark membranes and 19-23 light fin rays
  • Pectoral fins have a spine of varying roughness
  • 15-21 gill rakers on the first arch
Life History

 

Black bullheads are not well studied in California but in their native ranges their preferred habitats include ponds, small lakes, river backwaters, sloughs, and pools in slow, low gradient streams with muddy bottoms, and warm turbid water. The areas similar to this in California are mostly farm ponds, sloughs, reservoirs, and highly altered, lower reaches of rivers. Black bullhead are very hardy, however, and can also be found in waters with temperatures up to 35°C, salinities as high as 13 ppt, and dissolved oxygen levels as low as 1-2 mg/L. This has allowed them to be not only active invaders, but resilient survivors in harsh, temporary environments like ditches and intermittent streams. Black bullheads are very social fish and juveniles can be seen swimming in tight schools throughout the day and foraging together at dawn and dusk. Adults stay hidden under the cover of vegetation beds during the day but will come out to scour the bottom for food after dark. They are an omnivorous species that will eat nearly anything they can find. This includes aquatic insects, crustaceans, mollusks, and even earthworms and terrestrial insects when water levels have risen over previously dry land. Black bullheads will also scavenge dead fish found on the bottom and hunt live ones if they are slow enough to be caught.

 
Growth is controlled by temperature, food availability, and overcrowding leading to large differences between potential growth levels and the levels found in nature. In a lab a black bullhead can grow to 30 cm and 500 g in a single year while it would take 3-9 years to reach that size in the wild. These restrictions are especially prevalent in smaller ponds where growth can be stunted to between 17 and 25 cm in length. This does not stop wild individuals from reaching large sizes, however, with the largest fish on record being 61.3 cm in length and weighing 3.6 kg. Spawning occurs in June and July when temperatures exceed 20°C. Mating begins when the female clears a shallow depression for a nest with her snout and pectoral fins. During this time the male begins the mating ritual by rubbing up against her and brushing her with his barbels. Once the ritual is complete the female lays the eggs into the nest where they stick together forming a yellow mass. Females can lay up to 7,000 eggs per season but more commonly lay between 2,500 and 3,000. The two parents remain with the nest, fanning it with their fins in order to maximize the oxygen the eggs receive until they hatch 5-10 days later. The young will stay in the nest living off their yolk sacs for another 4-5 days before becoming free swimming in the following 2-3 weeks. They remain together in a tight ball under the protection of their parents however until they are about 25 mm in length.
Links to Other Research
Watershed

Black Crappie

Scientific Name
Pomoxis nigromaculatus
Native
Non-Native
Identification

Black crappie, captured in rotary screw trap on the Sacramento River at Knight's Landing on 2/26/2009. Photo by Dan Worth, California Department of Fish and Game.
Black crappie, captured in rotary screw trap on the Sacramento River at Knight's Landing on 2/26/2009. Photo by Dan Worth, California Department of Fish and Game.

Black crappie. Captured and released in the Delta Cross Channel, near Walnut Grove, CA, 5 June 2013. Photo by Gary Riddle.
Black crappie. Captured and released in the Delta Cross Channel, near Walnut Grove, CA, 5 June 2013. Photo by Gary Riddle.

Black crappie, showing dorsal fin with 7 spines, captured in rotary screw trap on the Sacramento River at Knight's Landing on 3/7/2009. Photo by Nicholas Miguel, California Department of Fish and Game.
Black crappie, showing dorsal fin with 7 spines, captured in rotary screw trap on the Sacramento River at Knight's Landing on 3/7/2009. Photo by Nicholas Miguel, California Department of Fish and Game.

  • Deep, laterally compressed bodies and small sloping heads depressed above the eyes
  • Whitish-silvery side coloration with heavy black spotting of indistinct pattern, a dark back, and a white belly
  • Anterior will turn nearly solid black when breeding
  • Dorsal fin is placed at back of body with rounded end symmetrical to the anal fin
  • Dorsal fin has 7-9 spines and 15-16 fin rays, anal fin has 6 spines and 17-19 rays, pectoral fins have 14-15 rays and pelvic fins have 1 spine and 5-6 rays
  • 38-44 scales on the lateral line
Life History

 

Black crappies (pronounced "croppie") are most commonly found in large, warm water lakes and reservoirs. Optimally, this water is between 27°C and 29°C but black crappies have been seen hunting at 6-7°C and are not under lethal conditions until 37-38°C. Black crappies can also be found in salinities up to 10 ppt and in areas with dissolved oxygen levels as low as 1-2 ppt, although only for a short period of time. During the day black crappies stay in schools around large, submerged objects only leaving in the evening and early morning to look for food. This foraging mainly involves floating in midwater, using their flat shape as a disguise, and grabbing everything that they can. When they are young their diet is mainly zooplankton and small insect larvae but as they get larger their choice in food shifts towards aquatic insects and other fish. This diversity in diet is aided by a protruding jaw suited for catching large prey and their fine gill rakers useful for capturing smaller organisms.

Black crappies mature in 2-3 years and spawn between March and July. Mating begins when temperatures exceed 12-17°C and peaks between 18°C and 20°C. Females can lay up to 188,000 eggs depending on their size with 3-4 year olds laying between 33,000 and 42,000. These eggs are left in nest depressions 20-23 cm in diameter, made by the male. Most nests are constructed in mud or gravel bottoms close to aquatic vegetation beds and in water less than 1 m deep. They are also commonly built within 2 m of each other creating a reproductive colony that offers the embryos some protection from predators. The young will stay here, protected by the male for a short time after hatching, before becoming free floating larvae feeding on zooplankton. California crappies tend to grow more slowly than their east coast counterparts, reaching 4-8 cm in their first year and 17-33 cm in their fourth year. The largest individual recorded was a 13 year old weighing 2.2 kg but crappies older than 6 years or weighing over 1 kg are rare.

Links to Other Research
Watershed

Blue Catfish

Scientific Name
Ictalurus furcatus
Native
Non-Native
Identification

Blue catfish, adult. Caught in Marion, Alabama on 9 February 1994. Photo by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.
Blue catfish, adult. Caught in Marion, Alabama on 9 February 1994. Photo by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.

Blue catfish, young-of-the-year. Photo by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.
Blue catfish, young-of-the-year. Photo by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.

  • Elongate body with projecting snout
  • Deeply forked tail with pointed lobes
  • Terminal mouth with white barbels
  • Maxillary barbels are just larger than the head
  • Pale blue to olive on the sides and white on the belly
  • Steeply humped before the dorsal fin
  • 30-35 rays in anal fin making a straight edge tapering downwards to the end of the caudal peduncle
  • Males also have a urogenital papilla extending towards the tail leaving one opening behind the vent compared to the females’ two openings
Life History

Blue catfish are traditionally found in deep channels of big rivers but can also be seen in large reservoirs and fish farm ponds. Stream dwelling catfish will spend their days on the bottom of moderate flow areas 8-10 m deep before moving into rapids and other swifter waters at night. In reservoirs they stay to the deep sections during the day and feed in the shallow regions at night. They can survive in temperatures from 0°C to 37°C and in salinities as high as 22 ppt but their growth peaks at 27°C and between 7 and 8 ppt. When they are very young, blue catfish eat mostly crustaceans and insects but when they are only 10 cm long they will begin feeding on fish and by the time they are 20-30 cm long fish make up the majority of their diet. In early summer, when water temperatures have exceeded 21-25°C, blue catfish will move towards the muddy bottomed pools and backwaters of their range to spawn. While their reproductive strategies have not been well studied in California it is known that blue catfish require cave-like sites for their nests and it is assumed that the males protect these sites before mating and after birth until their offspring are large enough to survive on their own. Within a year blue catfish are an average length of 22-26 cm long and can grow to incredible sizes as they get older. It is not uncommon for a blue catfish to grow to be larger than 1.6 m and weigh over 45 kg (Carlander 1969).

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Watershed

Blue Chub

Scientific Name
Gila coerulea
Native
Native Species
Identification

missing fish photo

  • Slender, pointed minnow, rarely exceed 38 cm SL
  • Large eyes, terminal mouth, maxillas extend to front margin of eye
  • Coloration: silvery sides, dark back
  • Breeding males have blue snout, orange sides and fins
  • Fin rays: dorsal 9, anal 8-9, pectoral 14-17
  • Lateral line scales: 58-71, decurved, small scales
Life History

 

Blue chubs are primarily found in shallow warm water lakes, though they also occur in small streams and deep lakes. Favorable habitat includes small, shallow, weedy sections of quiet large rivers. They are often found living near tui chubs. Blue chubs are capable of surviving in adverse conditions such as low levels of dissolved oxygen and water temperatures as high as 32°C. In lakes the chubs avoid deep water areas till cooler winter temperatures result in rising oxygen levels. They have omnivorous feeding habits and may consume algae, chironomid midge larvae and pupae, waterfleas, waterboatmen, and various forms of aquatic and terrestrial insects. Blue chubs grow rapidly until they reach sexual maturity at a size of around 12-15 cm SL. They spawn from May through August over gravel or rocky substrate in shallow water when temperatures are 15-18°C. Each female is surrounded by several males who fertilize her eggs as she releases them. Blue chubs continue to grow slowly and may reach a maximum age of 17 years.

Links to Other Research
Watershed
  • Butte Watershed
  • Lost Watershed
  • Upper Klamath Watershed

Blue Tilapia

Scientific Name
Oreochromis aureus
Native
Non-Native
Identification

missing fish photo

 

  • Deep, elongate, laterally compressed body
  • Cycloid scales, 16-23 along the first lateral line and 11-16 along the second
  • Bluntly pointed snout with a slightly oblique mouth that rarely extends past the outer margins of the eye
  • Females and non-breeding males are normally a pale gray to washed-out yellow with a series of bands on the sides
  • Spawning males have iridescent blue-gray heads with dark blue chins, bodies of pale blue, dorsal fins with a red border, and plain caudal fins with a pink upper margin
  • 14-17 spines and 9-14 rays on the dorsal fin
  • 1-3 spines and 7-12 rays on the anal fin
  • Truncate caudal fin
Life History

 

Blue tilapia can adapt to various habitats but are most commonly found in sloughs, backwaters, canals, and reservoirs. They are mostly a freshwater fish but can survive in salinities 2-3 times higher than that of sea water. They can also survive in water as cold as 5°C, lower than most other tilapia species can withstand. In California they feed primarily on aquatic plants and filamentous algae but in their native range they will also filter feed for zooplankton. Juveniles will prey on individual zooplankton until filtering becomes more energetically efficient.

Sexual maturity for both sexes is reached when they have grown to between 10 cm and 18 cm, usually within their first year. Spawning occurs when a male claims a territory and digs a shallow pit for a nest. He then displays in front of the female school, convincing a female to follow him back to the nest. The pair will swim in circles before the female deposits her eggs onto the nest and then takes them into her mouth. The male responds by releasing his milt which the female in turn, takes into her mouth to fertilize the eggs. Once this fertilization is complete, the male chases that female away and begins displaying for another. The female incubates the eggs in her mouth until the young are free swimming and capable of being released into the water. The young stay with their mother for a few days after release during which time they can retreat to the safety of her mouth when a predator approaches. At the end of this period the young form massive schools in shallow water while the female returns to the school of females and may spawn again. Breeding can be repeated every 33-59 days. In their native lakes blue tilapia can grow to be 8-16 cm in their first year and 16-27 cm in their second reaching a maximum length of 37 cm and weight of 1 kg.

Links to Other Research
Watershed

Bluegill

Scientific Name
Lepomis macrochirus
Native
Non-Native
Identification

Bluegill approximately 15 cm (6”) long. Location: Leonard Lake, California
Date: 8/6/2008 Photo: Lisa Thompson
Bluegill approximately 15 cm (6”) long. Location: Leonard Lake, California Date: 8/6/2008 Photo: Lisa Thompson

Bluegill with measurements Location: Leonard Lake, California Date: 8/6/2008 Photo: Lisa Thompson
Bluegill with measurements Location: Leonard Lake, California Date: 8/6/2008 Photo: Lisa Thompson

Bluegill with measurements. Location: Leonard Lake, California Date: 8/6/2008
Bluegill with measurements. Location: Leonard Lake, California Date: 8/6/2008

  • Deep, compressed body
  • Flexible blue or black flap on the rear of each operculum
  • Long pointed pectoral fins
  • Black spot on the rear of the dorsal fin
  • Narrow vertical black bars on the side
  • 11-12 anal, 13-14 pectoral, 10-12 dorsal, and 5 pelvic rays
  • 3 anal and 10 dorsal spines
  • 38-48 scales on the lateral line
  • Iridescent purple shine
  • Breeding males turn dark olive to bronze on their backs and sides, orange on their breast, iridescent black on the pelvic and anal fins, while a dark spot develops on the soft portion of the dorsal fin
Life History

 

Bluegills are most common in warm, shallow lakes, reservoirs, ponds, streams, and sloughs at low elevations. They can also be found in streams if there are deep, well covered and vegetated pools and warm summer temperatures. These populations will avoid the dangers of high flow by moving into backwaters or flooded regions. In all areas they prefer temperatures between 27°C and 32°C but can live in waters as cold as 2-5°C and as warm as 40-41°C. They are more limited by salinity levels however, occasionally being found in areas of 5 ppt but suffering from arrested development at 8 ppt and dying at 12 ppt. They grow best in areas with dissolved oxygen levels between 4 mg/L and 8 mg/L but can survive in levels less than 1 mg/L. Inside lakes and reservoirs bluegills are most often found among aquatic plants growing out of silt, sand, or gravel usually no deeper than 5 m. They are a highly opportunistic species, maneuverable enough to feed from the bottom, on vegetation, or in midwater. Aquatic insect larvae are preferred food but planktonic crustaceans, flying insects, and snails are common food items and small fish, fish eggs, and crayfish can be taken when available. This variety of options leads to a diversity in diets between populations that can vary dramatically depending on their location. Algae and aquatic vegetation can be used when other food is scarce but a consistent diet of this material will stunt growth. Bluegills will usually stay in one restricted area for most of their lives, due largely to their long breeding season. This lack of movement brings with it a great deal of knowledge of the area, however, and allows the bluegills to comfortably pick other fish clean of parasites and loose tissue, an activity unlikely to occur if the bluegill was not aware of the area’s potential predators.

Spawning occurs in summer when temperatures reach 18-21°C and may continue through to September. Bluegills, like many sunfish, have a variety of male mating strategies. The most straightforward and common type is known as a parental male. These males make up approximately 70% of the population and tend to be the largest males in area. They construct 20-30 cm wide and 5-15 cm deep nests out of the gravel, sand, or mud substrate in shallow water. Different males' nests will be built close to each other forming a protective colony but each nest is also intensely defended from the other males in the colony. The stronger males take advantage of this, controlling the central nests of the colony where lines of other males act as a protective wall against outside predators. While the nests are being constructed, females swim in schools around the nesting area until one is ready to mate. At this point a female will leave the school and swim toward the nests where she is courted by the dominant male in the immediate vicinity. They then swim together to the male’s nest where the female drops her eggs and the male fertilizes them. The eggs stick to debris on the bottom of the nest and stay there until they hatch. This will be repeated many times for both sexes resulting in as many as 62,000 eggs in one nest although 2,000-18,000 is more common. Each female will release between 2,000 and 50,000 eggs. Mating will also happen in a very short window of time so that the entire colony births in one large movement reducing the impacts of predation. The young are also protected by the parental males that will guard the nest and young for days after they hatch. In contrast the satellite and sneaker male mating types have no such obligation. Satellite males mimic females in size, coloration, and behavior in order to follow a mating parental pair into the nest and fertilize some of the dropped eggs. The sneaker male is less subtle and will instead wait at the edge of a colony before racing inside to spawn beside a mating parental couple. The parental male may make attempts to chase these groups away but often times this only allows a satellite male to fertilize all of a female’s eggs. While these alternate strategies may have the advantage of forcing the caretaker role on another, satellite and sneaker males are so battered by fights and chases that by the end of the spawning season they will often be in a greatly weakened state. Regardless of strategy the eggs will hatch 2-3 days later in 20°C water and the breeding cycle starts again a week later. The newly hatched young travel from the nest to beds of plants where they will stay except for a 6-7 week period when they are between 10 mm and 25 mm long in which they enter the water column and feed on plankton. In their first year they will grow to 4-6 cm and will add 2-5 cm each following year. Few individuals live longer than 6 years.

Links to Other Research
Watershed

Brook Stickleback

Scientific Name
Culaea inconstans
Native
Non-Native
Identification

Brook stickleback. Photo by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.
Brook stickleback. Photo by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.

  • Laterally compressed body
  • 5 short spines precede and are completely separate from the 9-11 rays of the dorsal fin
  • Anal fin with 1 spine and 9-11 rays
  • Pelvic fins are a single spine and a single stout ray
  • Pectoral fins have 9-11 rays
  • Round to truncated tail
  • 30-36 tiny bony plates run along either side on the lateral line
  • Olive-green back and sides, with a lighter belly and varying degrees of mottling
  • Breeding males are dark green to black and occasionally have red on the fins
  • Short caudal peduncle
  • Small oblique mouth

 

Life History

Brook sticklebacks prefer cool, clear waters with extensive aquatic plant beds. This finds them in a variety of habitats including spring ponds, slow moving streams, river edges, irrigation ditches, and clear lakes. They tend to stick close to shallow, weedy areas where they can hide in the plant beds or bury themselves in the substrate of organic matter when a threat is present. In these vegetation beds they hunt for small invertebrates, especially the larvae of midges and other insects, picking them off plants or catching them in the water column.

Brook sticklebacks breed between April and June of their second summer when temperatures reach 15-19°C. A male constructs a nest by collecting various pieces of debris from the bottom and attaching them to the base of an aquatic plant. He will then attract a female to the nest through a form of courtship dance. The female will lay 100-200 eggs in small batches that hatch 7-11 days later. During this time the male will maximize the embryos' oxygen intake by waving water over them with his fin. He will also guard the newly hatched larvae until they are active enough to escape the nest. Most brook sticklebacks only live to be 2 years old and average 61 mm TL. Individuals over 65 mm TL are rare and 87 mm TL is the recorded maximum.

Links to Other Research
Watershed

Brook Trout

Scientific Name
Salvelinus fontinalis
Native
Non-Native
Identification

Brook trout, captured in Lassen Creek, Modoc County, CA, on 8 July 2007.
Brook trout, captured in Lassen Creek, Modoc County, CA, on 8 July 2007.

Brook trout fry, approximately 24 mm (1
Brook trout fry, approximately 24 mm (1") long, in Pine Creek, CA (Eagle Lake), 30 May 2008. Photo by Gerard Carmona Catot.

Brook trout fry, approximately 36 mm (1.5
Brook trout fry, approximately 36 mm (1.5") long, in Pine Creek, CA (Eagle Lake), 30 May 2008. Photo by Lisa Thompson.

  • Large, slightly oblique mouth extends beyond the posterior margin of the eye and contains teeth on both jaws
  • 10-14 dorsal, 9-12 anal, 11-14 pectoral, and 8-10 pelvic fin rays
  • 110-132 scales on the lateral line
  • Straight to slightly forked tail
  • Dark, olive green back with light colored wavy lines (vermiculations), red spots with surrounding blue halos, and white on the leading edges of the pectoral, pelvic, and anal fins
  • Young have 8-10 parr marks and usually a few red yellow or blue spots
  • Spawning males are deep bodied with hooked jaws
  • Spawning females develop a protruding genital papilla
  • Both sexes may develop dusky-black bellies, red sides, and red lower fins when spawning
Life History

 

Brook trout are best suited to cold, clear lakes and streams and in California they have become well established in small, spring fed, headwater streams and isolated mountain lakes. They are adapted to the cold, existing comfortably at 14-19°C and feeding in waters as cold as 1°C. While they can acclimate to temperatures up to 26°C, anything over 19°C results in a reduction in growth. Brook trout will primarily eat terrestrial insects, aquatic insect larvae, and zooplankton as they drift at or near the surface but are also known to feed on benthic organisms and occasionally to be piscivorous. They will eat any time they can see their prey but the most intense feeding periods are in the evening and early morning. In areas of moderate flow, where food is in abundance, brook trout will create and defend feeding territories but in slower or faster waters this aggressive behavior is greatly reduced in favor of alternate foraging techniques.

Males can spawn by the end of their first summer and females their second but a year or two longer for both is common. In California the spawning season is usually between mid-September and early January when waters are between 4°C and 11°C. Females select the spawning site by looking for cooler areas deeper than 40 cm, with water upwelling through the substrate, pea- to walnut-sized gravel, and nearby cover. The upwelling is an important component because it controls the timing of embryo development and provides a steady flow of oxygen into the nest (redd). The female constructs the redd by shifting the gravel with her tail. This development attracts males to the site who will then compete for dominance until one establishes the authority to spawn. When the redd is prepared the pair will quiver next to each other and simultaneously release eggs and sperm into the depression. The female immediately covers the eggs in gravel, both protecting that group and creating a new redd for a new batch of eggs. About 14-60 eggs are laid per redd but 50-2,700 eggs total can be held by a single female. In California 200-600 eggs per female is the average so a female making more than 40 redds is not outside the realm of possibility.

In order to survive through the winter the embryos will not hatch for 100-144 days at 2-5°C and will remain in the gravel as alevins for another 3-4 weeks. As the water warms and they absorb their yolk sac, the young trout become more active, heading to shallow stream edges with emergent plants, backwater pools, or the shallow areas of lakes where they will be sheltered from wave action. Here they will feed on small crustaceans both from the bottom and in the water column. Their growth will be based mostly on the length of growing season, temperature, population density, and availability of food, but can also be influenced by water chemistry, other trout populations, and heredity. The fastest growth occurs in moderate elevation streams and lakes with limited populations of both brook trout and other species. Here they can reach 15 cm in their first year and 23-25 cm in their third. The largest individual recorded was 60 cm in length and weighed 4.4 kg. Most live to be only 4-5 years old, however, many dying from lack of energy in the winter after their first spawn. An interesting exception to this is in Mono County’s Bunny Lake where stunted growth kept lengths under 28 cm but allows some individuals to live for as long as 24 years.

Links to Other Research

Restoration of Wild Eagle Lake Rainbow Trout (see papers and reports for brook trout removal data)

Watershed

Brown Bullhead

Scientific Name
Ameiurus nebulosus
Native
Non-Native
Identification

Brown bullhead. Caught in Seneca County, New York. Photo by Arthur Masloski, January 2009.
Brown bullhead. Caught in Seneca County, New York. Photo by Arthur Masloski, January 2009.

 

  • Heavy body
  • Blunt snout with a terminal mouth and 8 dark barbels: 6 on the chin and 1 on each side of the mouth
  • Short anal fin with same color on both membranes and the 21-24 rays
  • Dorsal and pectoral fins have 5-9 saw-like teeth on the posterior edge
  • 6-7 dorsal fin rays
  • 11-15 gill rakers on first arch
  • Plain yellow-brown with dark molting on the side and white to yellow on the belly
Life History

 

The brown bullhead is an extremely adaptable species, finding niches in a variety of habitats from warm turbid sloughs to clear mountain lakes. In California they are found mostly in larger bodies of water, like foothill reservoirs, where they stay towards the deep end of the littoral zone, near aquatic plant beds and muddy substrate. When found in rivers, bullheads prefer slow moving, low gradient, turbid streams with deep pools, aquatic plant beds, and soft bottoms. This diversity of habitat use comes from the species’ resilient nature. Bullheads can survive in temperatures that range from 4°C to 37°C, salinities as high as 13 ppt, and alkalinity levels up to a pH of 9. Incredibly, they can also survive in water with less than 1 mg/L of dissolved oxygen by becoming torpid if in cold conditions and gulping air in hot conditions. Bullheads feed at night in groups, sometimes organized under a size-based hierarchy. These groups swim close to the bottom, running their barbels along the ground detecting potential prey hidden by debris and murky waters. For young bullheads this prey consists mostly of midge larvae and small crustaceans but their diet will expand to larger insect larvae and small fish as they get older. These are only the more common prey examples, however, as bullheads are incredibly opportunistic, eating nearly anything that can fit in their mouths.

Bullheads usually reach sexual maturity by age 3 and spawn in May through mid-July when water temperatures have reached 21°C. After a courtship ritual, a female will deposit 2,000-14,000 eggs in a nest she has constructed previously using natural depressions. Once the eggs are fertilized the parents will protect them from predators and other bullheads while stirring the water around the eggs to increase oxygen levels. The eggs hatch 6-9 days later but the young stay in the nest for up to a week more feeding on their yolk sacs. At this point the young become free swimming but stay together in a tightly packed ball protected by their parents until they reach 50 mm in length. Over the next year they will grow rapidly, reaching 7-10 cm by the end of their first year. The largest individual recorded was 53.2 cm long and weighed 2.2 kg but it is rare to have a bullhead longer than 30 cm or heavier than 450 g.

Links to Other Research
Watershed

Brown Trout

Scientific Name
Salmo trutta
Native
Non-Native
Identification

Brown trout, approximately 20 cm (8”) long. Location: Deer Creek, California 
Date: 6/21/2007.
Brown trout, approximately 20 cm (8”) long. Location: Deer Creek, California Date: 6/21/2007.

Brown trout. Photo by Dan Worth, California Department of Fish and Game.
Brown trout. Photo by Dan Worth, California Department of Fish and Game.

Brown trout, approximately 7 cm (2.5”) long. Location: Deer Creek, California 
Date: 6/21/2007
Brown trout, approximately 7 cm (2.5”) long. Location: Deer Creek, California Date: 6/21/2007

Brown trout, approximately 7 cm (2.5”) long. Location: Deer Creek, California 
Date: 6/21/2007
Brown trout, approximately 7 cm (2.5”) long. Location: Deer Creek, California Date: 6/21/2007

  • Heavy bodied with a large mouth often extending beyond the rear margin of the eye
  • Well developed teeth on both jaws
  • 12-14 dorsal, 10-12 anal, 9-10 pelvic, and 13-14 pectoral fin rays
  • Thick caudal peduncle with a straight tail in adults and a slightly forked tail in juveniles
  • Males have a rounded anal fin while that of females is slightly indented
  • 120-130 small scales on the lateral line
  • Dark to olive brown on the back, yellow brown on the sides, white to yellow on the belly, and red or orange adipose fin
  • Black spots on the gill covers, head, sides (usually with a pale halo), tail, and the adipose and dorsal fin
  • Red spots on the lower sides (only trout with both red and black spots)

 

Life History

Brown trout can be found in a large variety of waters, from spring fed trickles to large lakes and reservoirs, but find their optimal habitat in medium to large, slightly alkaline, clear streams, with swift ripples and deep pools. In general, as the trout get older they move towards deeper waters with fry staying in low velocity edge waters less than 30 cm deep, juveniles found in higher velocity water 50-75 cm deep with large rocks, logs, and overhead cover, and adults keeping to pools 0.7-3.5 m deep. There are also differences in habitat based upon the trout’s maturity level. Non-reproducing fish are usually sedentary, staying near or under the same piece of dense cover constantly, but reproducing fish will establish a feeding territory and actively protect it. As the fish get larger their territory will expand until they reach approximately 25 cm in length. At this point they become more mobile, staying under cover during the day, but patrolling a larger area at night for active feeding. Although temperatures of 28-29°C can be survived for a short period of time, brown trout are generally cold water fish, preferring temperatures between 12°C and 20°C. Brown trout may also be sea run, particularly in their native Europe, North Africa, and western Asia, but this is rare in California.

The diet of a brown trout can change dramatically over the course of its lifetime. Smaller individuals focus on drift organisms, in particular terrestrial insects, before shifting to more bottom dwelling invertebrates as they get larger. By the time they are 25 cm in length and have moved away from a feeding territory they will actively pursue other fish, crayfish, and dragonfly larvae; brown trout over 40 cm feed almost exclusively on other fish. All sizes will eat terrestrial insects in late summer when there are massive hatching events creating a large enough supply of food to support even the largest individuals. They will feed at any time of the day but most intensely at dusk and dawn. Individuals may become specialized at hunting one certain type of prey while others are generalists in their prey choices. This results in a wide diversity of diets within a population.

Maturity is usually reached in the 2nd or 3rd year and breeding occurs in November and December. A rise in water level signals the trout to head to spawning territory but the final redd site is not selected until temperatures drop below 6-10°C. Streams with riffles that have pea- to walnut-sized gravel are usually required for spawning, with the best locations at the tails of pools with deeper, less turbulent water, and more complete cover. A female constructs the redd in the gravel bottom while the male protects and courts her. Once the redd is complete the pair will hold position next to each other and release their eggs and sperm simultaneously. After fertilization the female will, in a single shift of gravel, bury the eggs she has just laid and construct a new redd for the next batch. Each redd will hold 100 to 250 eggs and a female can lay between 200-21,000 over the course of a breeding season. This difference in fecundity can sometimes be based on the trout’s surroundings. In heavy cover it is more common to find large eggs in smaller numbers while females in areas of lighter cover tend to produce a greater number of smaller eggs. It can take anywhere between 4 and 21 weeks for the embryos to hatch, but 7-8 weeks is the norm. Alevins will emerge 3-6 weeks later and move towards calm, nearshore waters where they find cover among large rocks and under overhanging plants.

These young trout will grow to 3-8 cm in length their first year and 7-22 cm in their second. This diversity can be caused by differences in temperature, alkalinity, dissolved solids, turbidity, population density, or food availability. The largest individual ever recorded was a 103 cm long fish from Scotland and the largest California fish was measured at 12 kg. Norwegian brown trout have been known to live as long as 35 years but in California 9 years old seems to be the limit.

Links to Other Research

Effects of Pulsed Flows from Dams on Fishes: Field and Lab Studies (see 1-day pulse study for brown trout data)

Watershed

California Killifish

Scientific Name
Fundulus parvipinnis
Native
Native Species
Identification

California killifish, captured from Zuma Creek Lagoon, Los Angeles County, CA on 26 January 2006.  Photo by Steve Howard.
California killifish, captured from Zuma Creek Lagoon, Los Angeles County, CA on 26 January 2006. Photo by Steve Howard.

  • Small, thick bodies, up to 115 mm SL, over 85 mm SL rare
  • Square tail, small pelvic fins
  • Small oblique mouth, rows of cone-shaped teeth
  • Coloration: green back and sides, yellowish-brown underside (sexual dimorphism present):
  • Males:long anal fin, approximately 20 black bars along each side
  • Breeding males: dark brown back; bright yellow belly, lower head, and paired fins
  • Females: black bars absent, faint lateral band present, oviducal pouch on anterior anal rays
  • Fin Rays: anal 11-13, dorsal 12-15
  • Lateral line series: 3-37 (incomplete)
Life History

 

California killifish are primarily found among beds of aquatic vegetation in shallow lagoons and estuaries. Though they usually inhabit brackish water, killifish can withstand salinities ranging from 0 to 128 ppt. In addition they can tolerate pollution, changes in dissolved oxygen, and temperatures ranging from 11-25°C. Large killifish are more adaptable to changes in oxygen levels, whereas smaller fish adjust better to changes in salinity. They may be found in freshwater as far as 1-2 kilometers upstream, and have the ability to complete their entire lifecycle in freshwater. In bays or estuaries killifish form loose shoals and follow the changes in tide. They feed mostly on planktonic and benthic invertebrates with major food sources varying with location and time. Fish living near tidal flood zones feed on a diverse group of organisms and tend to feed at high tide. In comparison, killifish not living in these zones have limited feeding options. Most California killifish have a one year life history and reach full adult size in 6-7 months. Some adults reach an age of 2-3 years. Peak breeding occurs from May through June, sometimes starting earlier and lasting longer. Female killifish lay their eggs over a period of weeks or months, usually in pools found on tidal flats. They lay approximately 60-440 eggs that adhere to aquatic vegetation for the incubation phase. Most adult killifish perish after breeding.

Links to Other Research
Watershed
  • Aliso-San Onofre Watershed
  • Calleguas Watershed
  • Central Coastal Watershed
  • Cottonwood Tijuana Watershed
  • Los Angeles Watershed
  • Newport Bay Watershed
  • San Diego Watershed
  • San Gabriel Watershed
  • San Luis Rey-Escondido Watershed
  • Santa Ana Watershed
  • Santa Barbara Coastal Watershed
  • Santa Clara Watershed
  • Santa Margarita Watershed
  • Santa Monica Bay Watershed
  • Seal Beach Watershed
  • Ventura Watershed

California Roach

Scientific Name
Lavinia symmetricus
Native
Native Species
Identification

California roach. Captured from the Gualala River. Photo by Carl Page, ARS Consulting.
California roach. Captured from the Gualala River. Photo by Carl Page, ARS Consulting.

  • Small chunky fish, usually less than 100 mm TL, rarely exceed 120 mm SL
  • Large head, small downward turned mouth
  • Coloration: body is usually gray to blue on top, silvery underside
  • Spawning adults: may develop orange and red colorations on chin and paired fins
  • Breeding males may develop series of nodes or tubercles on head
  • Fin rays: dorsal 7-9, anal 6-8
  • Lateral line scales: 47-63
Life History

 

California roach are capable of adapting to varying habitats from coastal streams to mountain foothill streams. They are predominately found in small warm streams but are capable of thriving in larger colder streams with diverse conditions. They may actually occupy several different habitat types within a single drainage. Extreme tolerance includes temperatures ranging from 30-35ºC and dissolved oxygen levels as low as 1-2 ppm. In-stream location may vary depending on geography and predators. When California roach share water with Sacramento pikeminnows, roach will stick to the stream margins, whereas in the absence of these piscivorous fish roach may venture into deeper pools. California roach are omnivorous and diet may depend on stream size and food availability. In smaller rivers roach feed mostly on filamentous algae, supplementing their diet with crustaceans and insects. In larger rivers these fish may focus on a diet of aquatic insects year round. The growth and development of California roach is largely seasonally dependent. Most growth occurs during the summer months and roach may grow 20-40 mm in a year. Most fish of this species reach sexual maturity at age 2-3 and rarely live beyond three years total. Spawning occurs in March through early July, and timing is temperature dependent. California roach breed in gravel beds or riffles where groups of females lay eggs on and into the substrate. One or two males follow each female closely to fertilize the groups of eggs. Each female may produce 250-2,000 eggs per year depending on body size. The eggs hatch in 2-3 days, but the larvae remain in the protection of the gravel substrate before emerging to swim.

Links to Other Research
Watershed
  • Alisal-Elkhorn Sloughs Watershed
  • Big-Navarro-Garcia Watershed
  • Bodega Bay Watershed
  • Carmel Watershed
  • Carrizo Plain Watershed
  • Cottonwood Headwaters Watershed
  • Coyote Watershed
  • Cuyama Watershed
  • Estrella Watershed
  • Goose Lake Watershed
  • Gualala-Salmon Watershed
  • Honcut Headwaters Watershed
  • Lower American Watershed
  • Lower Bear Watershed
  • Lower Butte
  • Lower Cache Watershed
  • Lower Cottonwood Watershed
  • Lower Eel Watershed
  • Lower Feather Watershed
  • Lower Pit Watershed
  • Lower Sacramento Watershed
  • McCloud Watershed
  • Middle Fork Eel Watershed
  • Middle Fork Feather Watershed
  • Middle San Joaquin-Lower Merced-Lower Stanislaus Watershed
  • Mill Watershed
  • North Fork American Watershed
  • North Fork Feather Watershed
  • Pajaro Watershed
  • Panoche-San Luis Reservoir Watershed
  • Russian Watershed
  • Sacramento Headwaters Watershed
  • Sacramento-Lower Cow-Lower Clear Watershed
  • Sacramento-Lower Thomes Watershed
  • Sacramento-Stone Corral Watershed
  • Sacramento-Upper Clear Watershed
  • Salinas Watershed
  • Salmon Watershed
  • San Francisco Bay Watershed
  • San Francisco Coastal South Watershed
  • San Joaquin Delta Watershed
  • San Lorenzo-Soquel Watershed
  • San Pablo Bay Watershed
  • South Fork American Watershed
  • South Fork Eel Watershed
  • Suisun Bay Watershed
  • Tomales-Drake Bays Watershed
  • Tulare-Buena Vista Lakes Watershed
  • Upper Bear Watershed
  • Upper Butte
  • Upper Cache Watershed
  • Upper Calaveras Watershed
  • Upper Chowchilla-Upper Fresno Watershed
  • Upper Coon-Upper Auburn Watershed
  • Upper Cosumnes Watershed
  • Upper Cow-Battle Watershed
  • Upper Deer-Upper White Watershed
  • Upper Dry Watershed
  • Upper Eel Watershed
  • Upper Elder-Upper Thomes Watershed
  • Upper Kaweah Watershed
  • Upper King Watershed
  • Upper Los Gatos-Avenal Watershed
  • Upper Merced Watershed
  • Upper Mokelumne Watershed
  • Upper Pit Watershed
  • Upper Putah Watershed
  • Upper San Joaquin Watershed
  • Upper Stanislaus Watershed
  • Upper Stony Watershed
  • Upper Tule Watershed
  • Upper Tuolumne Watershed
  • Upper Yuba Watershed

Channel Catfish

Scientific Name
Ictalurus punctatus
Native
Non-Native
Identification

Channel catfish, caught in Nacimiento Reservoir in May 2008 by Teejay O'Rear. Photo by Amber Manfree.
Channel catfish, caught in Nacimiento Reservoir in May 2008 by Teejay O'Rear. Photo by Amber Manfree.

Channel catfish, captured in rotary screw trap on Sacramento River at Knight's Landing. Photo by Dan Worth, California Department of Fish and Game.
Channel catfish, captured in rotary screw trap on Sacramento River at Knight's Landing. Photo by Dan Worth, California Department of Fish and Game.

Channel catfish. Location: Balboa Park reflecting pond, San Diego, CA, 2009. The fish, estimated to be 10-12 years old, was popular with visitors. It died 24 May 2009, apparently of natural causes. Weight: 10.3 kg (22.7 lb). Photo by Neal Matthews.
Channel catfish. Location: Balboa Park reflecting pond, San Diego, CA, 2009. The fish, estimated to be 10-12 years old, was popular with visitors. It died 24 May 2009, apparently of natural causes. Weight: 10.3 kg (22.7 lb). Photo by Neal Matthews.

  • Elongate body with a small head
  • Deeply forked tail with pointed lobes
  • Terminal mouth with 1 black barbel on either side and 4 dusky to white chin barbels
  • Maxillary barbels are longer than the head
  • Upper jaw protrudes past lower jaw
  • Gray-blue on the sides, often with a olive green tinge, fading to white on the belly covered in scattered black spots
  • Young have black tipped fins
  • Spawning males become dark with enlarged heads, thickened lips, fatty pads behind the eyes, and thickened fin membranes
  • Males also have a urogenital papilla extending towards the tail leaving one opening behind the vent compared to the 2 openings on females
  • 5-6 soft rays in the dorsal fin
  • 24-29 rays in anal fin
  • 4-5 soft rays in pectoral fins
Life History


Channel catfish are found mostly in the main channels of large, warm water streams with sand, gravel, or rubble bottoms but can also be found in farm ponds, reservoirs, and turbid, muddy bottomed rivers. They are capable of surviving in waters with salinities as high as 10 ppt, temperatures as high as 36-38°C, and dissolved oxygen levels as low as 1-2 mg/L. Adults stay in pools or beneath logjams and undercut banks during the day and move into the faster moving parts of the stream at night to feed. Juveniles are not strong enough swimmers for these currents and instead stay in riffles where the flow is slowed by the rocky bottom. Channel catfish are technically an omnivorous species but they tend to be more predatory in practice. Juveniles feed on crustaceans and insect larvae and will begin hunting fish and crayfish as they grow older. An individual larger than 30-38 cm will focus its diet towards fish but will eat anything from insects to small mammals if it can fit it in its mouth.

Growth is variable depending on location but in good habitat channel catfish will reach a length 7-10 cm in their first year and 35-45 cm in their fifth. Some fish have been found to live longer than 40 years, weigh over 26 kg, and grow to be longer than 1 m but California fish older than 10 years or longer than 53 cm are rare. Reproductive timing is also fairly variable with first spawning points ranging from 2 to 8 years old and lengths between 18 and 56 cm, but the typical maturation point is 3 years old and at least 30 cm in length. Depending on the region, spawning occurs between April and August when temperatures are between 21°C and 29°C. Channel catfish need sheltered, cave-like sites for nests and often use old muskrat burrows, undercut banks, logjams, riprap of large rocks, and even dumped barrels. These may sometimes be difficult to find and while some females may spawn twice in a season it is not uncommon for planted populations to fail to spawn entirely. If an appropriate area is found, males will clear away and protect the nest site before the pair mates. They will mate multiple times until the female lays all her eggs: between 2,000 and 70,000 depending on her size. The males will stay with the nest, fanning it to maximize the oxygen available to the eggs until they hatch 5-10 days later. The 10-12 mm long juveniles start swimming after a couple days but will not leave the protection of the nest and the males until 7 days after hatching. When the juveniles do leave the nest they may school together as a group for some time before departing on their own when they reach approximately 25 mm in length.

Links to Other Research
Watershed

Chinook Salmon

Scientific Name
Oncorhynchus tshawytscha
Native
Native Species
Identification

Chinook salmon, female spring-run spawner. Location: Butte Creek, California. Date: 9/16/2006. Thanks to Clint Garman, CDFG. Photo by Lisa Thompson, UC Davis.
Chinook salmon, female spring-run spawner. Location: Butte Creek, California. Date: 9/16/2006. Thanks to Clint Garman, CDFG. Photo by Lisa Thompson, UC Davis.

Chinook salmon. Location: Alaska. Photo courtesy of Steve Tjosvold, UC Cooperative Extension.
Chinook salmon. Location: Alaska. Photo courtesy of Steve Tjosvold, UC Cooperative Extension.

Chinook salmon parr, approximately 10 cm (4”) long. Location: Center for Aquatic Biology and Aquaculture, UC Davis. Date: 5/21/2007. Thanks to Timothy Mussen.
Chinook salmon parr, approximately 10 cm (4”) long. Location: Center for Aquatic Biology and Aquaculture, UC Davis. Date: 5/21/2007. Thanks to Timothy Mussen.

Chinook salmon. Spring-run Chinook salmon spawners swimming in Butte Creek, CA on 14 September 2006. Photo by Lisa Thompson, UC Davis.
Chinook salmon. Spring-run Chinook salmon spawners swimming in Butte Creek, CA on 14 September 2006. Photo by Lisa Thompson, UC Davis.

Chinook salmon. Spring-run Chinook salmon spawners swimming in Butte Creek, CA on 12 September 2006. Photo by Lisa Thompson, UC Davis.
Chinook salmon. Spring-run Chinook salmon spawners swimming in Butte Creek, CA on 12 September 2006. Photo by Lisa Thompson, UC Davis.

Chinook salmon. Spring-run Chinook salmon spawners swimming over redds (nests) in Butte Creek, CA on 14 October 2008. The redds are the lighter gray, cleaned gravel. Photo by Lisa Thompson, UC Davis.
Chinook salmon. Spring-run Chinook salmon spawners swimming over redds (nests) in Butte Creek, CA on 14 October 2008. The redds are the lighter gray, cleaned gravel. Photo by Lisa Thompson, UC Davis.

Coho salmon fry (top) and a Chinook salmon fry (bottom). Location:  Shasta River, California. Date:  4/13/2004. Fish were approximately 6.5 cm long (2.5”). Photo by Lisa Thompson, UC Davis.
Coho salmon fry (top) and a Chinook salmon fry (bottom). Location: Shasta River, California. Date: 4/13/2004. Fish were approximately 6.5 cm long (2.5”). Photo by Lisa Thompson, UC Davis.

  • Commonly 75-80 cm SL (9-10kg), sometimes exceeding 140 cm SL (45 kg)
  • Various shades: white, pink, red
  • Spots on both lobes of tail, black pigment along jaw
  • Spawning adults olive brown or dark maroon, males darker
  • Spawning males may have slightly hooked jaws and humped back
  • Juvenile Chinook: 6-12 large parr marks, window-like adipose fin with dark pigmented edge, anal fin has white leading edge like coho, no black pigmented line following
  • Fin rays: dorsal 10-14, anal 14-19, pectoral 14-19, pelvic 10-11
  • Lateral line scales:130-165 pored
Life History

Chinook salmon are the largest of all the Pacific salmon species and are thus commonly called king salmon. These fish are anadromous: they are born and rear in freshwater, migrate to the ocean to feed, and return to their natal streams to spawn and die. Two main forms of anadromy exist in the Chinook salmon, specifically stream-type and ocean-type, although there are many variations on these life history themes. The duration of time spent in freshwater and then in saltwater varies between types of anadromy and between individual populations or runs of fish. Stream-type Chinook salmon typically spend more than a year in freshwater before swimming out to sea, where their stay will vary from one to several years. Stream-type Chinook salmon return to their natal streams in spring or summer before reaching full maturity. The ocean-type Chinook salmon spend several months to a year in freshwater before smoltification. The ocean phase then varies from one to several years. Ocean-type Chinook salmon return to their natal streams and spawn in August to December. Within the classification as stream or ocean-type Chinook salmon, fish may be further labeled based upon the time of spawning runs (migration), i.e. fall-run, late fall-run, winter-run, or spring-run. The spawning fish typically choose riffle bregions with large gravel substrate that may be near deep pools for cover. The female builds a series of nests or redds in the gravel where she deposits a total of 2,000 to 17,000 eggs depending on body size. The males fertilize the eggs, which will remain in the gravel for 40-60 days. When the alevins hatch they remain in the safety of the substrate for another 4-6 weeks while absorbing the nutrients of a yolk sac. When young Chinook salmon emerge as fry they are typically swept down to areas of slower water velocities. Young Chinook salmon tend to occupy a specific pool or area before moving downstream to the ocean. Typically small fry occupy the margins of a stream: back eddies, behind roots and logs, and other areas of bank cover. As the fish grow they begin to move into deeper and faster water. Growth rates are largely influenced by water temperature and the optimal range is 13-18°C. Young Chinook salmon will survive and grow within the range of 5-19°C, whereas steady temperatures above 24°C are lethal. Juveniles feed primarily on drifting insects of different sizes and stages, though the Chinook salmon may also consume zooplankton or fish larvae. Most feeding occurs at dawn and in the afternoon when favored food sources are present in the water column. Throughout their residence in freshwater, juvenile Chinook salmon feed opportunistically and the prey size remains fairly constant. When Chinook salmon reach the ocean, the salmon focus on a diet of crustaceans and other fish, fueling rapid growth rates.

Videos of spring-run Chinook salmon:

Flash Video
Spring-run Chinook salmon spawners digging and guarding redds (egg nests). Butte Creek, CA, in 2011. Video by Michael Smith.

Flash Video
Spring-run Chinook salmon spawners in Butte Creek, CA, in 2011. Video by Michael Smith. Note position of spawning area, just upstream of the riffle.

<img src="//ucanr.edu/media/sb379597.png" alt="Image from Flash Video" />
Chinook salmon (spring-run) adults in Butte Creek, California in 2007. Video by Jeff Sanchez.

<img src="//ucanr.edu/media/sb379598.png" alt="Image from Flash Video" />
Chinook salmon (spring-run) juveniles in Butte Creek, California in 2007. Note: The fish with two or three dark spots on their sides and downturned mouths are Sacramento sucker juveniles. Video by Jeff Sanchez.

Links to Other Research
Watershed
  • Bodega Bay Watershed
  • Chetco Watershed
  • Coyote Watershed
  • Honcut Headwaters Watershed
  • Lower American Watershed
  • Lower Bear Watershed
  • Lower Butte
  • Lower Calaveras-Mormon Slough Watershed
  • Lower Cosumnes-Lower Mokelumne Watershed
  • Lower Cottonwood Watershed
  • Lower Eel Watershed
  • Lower Feather Watershed
  • Lower Klamath Watershed
  • Lower Sacramento Watershed
  • Lower Yuba Watershed
  • Mattole Watershed
  • Middle Fork Eel Watershed
  • Middle San Joaquin-Lower Chowchilla Watershed
  • Middle San Joaquin-Lower Merced-Lower Stanislaus Watershed
  • Mill Watershed
  • Mill-Big Chico Watershed
  • Russian Watershed
  • Sacramento Headwaters Watershed
  • Sacramento-Lower Cow-Lower Clear Watershed
  • Sacramento-Lower Thomes Watershed
  • Sacramento-Stone Corral Watershed
  • Sacramento-Upper Clear Watershed
  • Salmon Watershed
  • San Francisco Bay Watershed
  • San Joaquin Delta Watershed
  • San Pablo Bay Watershed
  • Scott Watershed
  • Shasta Watershed
  • Smith Watershed
  • South Fork Eel Watershed
  • South Fork Trinity Watershed
  • Suisun Bay Watershed
  • Tomales-Drake Bays Watershed
  • Trinity Watershed
  • Upper Bear Watershed
  • Upper Butte
  • Upper Coon-Upper Auburn Watershed
  • Upper Cosumnes Watershed
  • Upper Cow-Battle Watershed
  • Upper Eel Watershed
  • Upper Merced Watershed
  • Upper Stanislaus Watershed
  • Upper Tuolumne Watershed

Chum Salmon

Scientific Name
Oncorhynchus keta
Native
Native Species
Identification

Chum salmon, adult. Captured at the mouth of Chico Creek on Puget Sound, in Kitsap County, Washington, on 8 November 2007. The fish was caught on a fly and released. Photo courtesy of Larry Coté.
Chum salmon, adult. Captured at the mouth of Chico Creek on Puget Sound, in Kitsap County, Washington, on 8 November 2007. The fish was caught on a fly and released. Photo courtesy of Larry Coté.

Chum salmon, adult, head. Captured at the mouth of Chico Creek on Puget Sound, in Kitsap County, Washington, on 8 November 2007. Photo courtesy of Larry Coté.
Chum salmon, adult, head. Captured at the mouth of Chico Creek on Puget Sound, in Kitsap County, Washington, on 8 November 2007. Photo courtesy of Larry Coté.

Chum salmon habitat. Adult fish captured at the mouth of Chico Creek on Puget Sound, in Kitsap County, Washington, on 8 November 2007. Photo courtesy of Larry Coté.
Chum salmon habitat. Adult fish captured at the mouth of Chico Creek on Puget Sound, in Kitsap County, Washington, on 8 November 2007. Photo courtesy of Larry Coté.

  • Maximum size around 1 m SL (15 kg), typically 80 cm SL (6-7 kg)
  • Coloration and characteristics:
    • Spawning adults: dark olive back, dark maroon sides, greenish vertical bars, whitish tip of anal and pelvic fins
    • Males: slightly humped, heavy bodies, hooked snout with canine teeth
    • Females: maroon sides lighter, hump absent, snout less hooked, mid-lateral stripe present
    • Ocean: silvery body, black spots on back and caudal fin absent, speckles may be present
    • Juveniles:6-14 pale parr marks, marks narrower than interspaces, silvery green sides, mottled green back
  • Fin rays: dorsal 10-14, anal 13-17, pectoral 14-16, pelvic 10-11
  • Lateral line scales: 124-153
Life History

Chum salmon have an anadromous life history that is typically completed in 3-5 years, with a few fish living up to 7 years. When young chum fry emerge from the gravel many will immediately swim downstream, migrating primarily at night, without stopping to feed. The juvenile chum salmon that do remain within the stream for a while tend to feed on crustaceans and insects. Within the estuary juvenile chum salmon diet will change as the fish progress out into deeper water. In shallow water they may feed on copepods and amphipods. As chum salmon grow and move further offshore they begin to add crustacean larvae, larvaeceans, euphausids, pteropods, and fish to their diet. Once the chum salmon move out into the open ocean they are epi-pelagic and prey on gelatinous zooplankton such as jellyfish. In southern populations of chum salmon, adults return to spawn as mostly 3 and 4 year old fish, though in northern populations the spawners are predominantely 4 and 5 years old. Chum salmon have two stock classes based upon the time of spawning. Early run chum salmon spawn from June-September, whereas late-run fish spawn from August-January. Southern populations (Washington, Oregon, California) are late-run fish that enter a stream when flows increase and temperatures cool. Optimal migration temperatures range from 8.3-15.6°C and optimal spawning occurs within a window of 7.2-12.8°C. Chum salmon may spawn anywhere from the estuary up, though they mostly spawn within the first 200 river kilometers. Wherever they reach, chum salmon return very closely to their native waters and find small diameter spawning gravels with adequate flow and dissolved oxygen (80% saturation). The females dig a series of 4-6 redds in succession in the substrate where they deposit an average of 2,400-3,100 eggs in a downstream to upstream direction. As she moves upstream, the female deposits a decreasing number of eggs in each redd. Male fish fertilize the eggs and may become aggressive and territorial, warding off other fish or “sneakers” who might try to fertilize the egg deposits. Male fish are sexually active for 10-14 days and may fertilize the eggs of several females. Fertilized eggs take 2-6 months to hatch. The emergent alevin remain within the gravel for another 30-50 days living off the sustenance of their yolk sac before rising up into the water column.

Links to Other Research
Watershed
  • Lower Klamath Watershed
  • Smith Watershed
  • Trinity Watershed

Coastrange Sculpin

Scientific Name
Cottus aleuticus
Native
Native Species
Identification

Coastrange sculpin, approx. 85 mm (3.5
Coastrange sculpin, approx. 85 mm (3.5") TL. Location: Lower Smith River, CA. Date: c. 1993. Photo by Jason White, Redwood Sci. Lab, US Forest Service

  • Small fish: usually less than 14 cm TL, capable of 17 cm TL
  • Large head, slender body and caudal peduncle, complete lateral line
  • Prickles behind pectoral fin only
  • Pelvic fins reach the vent when flattened, pair of posterior nostrils, single chin pore
  • Dark mottled coloring with white belly, 2 or 3 dark bands below and behind 2nd dorsal fin
  • Rear edge of 1st dorsal fin lacks dark spot
  • Adults have barred fins
  • Breeding males have long genital papillae, orange spot on caudal peduncle, and orange band on first dorsal fin
  • Pre-opercular spine (1) and 5-7 gill rakers
  • Fin spines/rays: pelvic 1 spine/4 rays, 1st dorsal 8-10 weak spines, 2nd dorsal 17-20 rays, pectoral 13-16 rays
  • Lateral line scales: 34-44 (complete)
Life History

Coastrange sculpins are usually found in coastal streams within 20 km of the estuary or ocean, though they have been found living over 120 km upstream. Coastrange sculpins primarily inhabit swift water in rocky or cobbled streams and they require areas with adequate cover for protection. Water temperatures are usually less than 20-22ºC. These fish often share their territory with prickly sculpin, threespine sticklebacks, and anadromous salmonids. Coastrange sculpins feed mostly at night on insects and bottom dwelling invertebrates like clams and snails. Adults may eat other small fish and amphibians. In areas of salmonid spawning the sculpin may feed on stray eggs. The juvenile fish concentrate on the larval stages of mayflies, caddisflies and the like, while the older fish may eat the nymphs of such organisms. Adult coastrange sculpins may reach sexual maturity in 2–3 years and are believed to live up to 8 years. Most spawning occurs in an estuarine environment from January to March, though breeding may occur farther upstream and later in the year. Females lay 100-1,764 eggs per year, using the underside of rocks to hide their deposits. When the eggs hatch most of the larvae are swept downstream into an estuary, lagoon, or deeper river pool. The larvae take on a planktonic form for 3-5 weeks before settling to the bottom of a stream. From there the juvenile fish will grow and move progressively upstream. Generally speaking the younger fish live downstream of the older and larger fish.

Links to Other Research
Watershed
  • Alisal-Elkhorn Sloughs Watershed
  • Big-Navarro-Garcia Watershed
  • Bodega Bay Watershed
  • Carmel Watershed
  • Central Coastal Watershed
  • Chetco Watershed
  • Gualala-Salmon Watershed
  • Illinois Watershed
  • Lower Eel Watershed
  • Lower Klamath Watershed
  • Mad-Redwood Watershed
  • Mattole Watershed
  • Pajaro Watershed
  • Russian Watershed
  • Salinas Watershed
  • Salmon Watershed
  • San Francisco Bay Watershed
  • San Francisco Coastal South Watershed
  • San Lorenzo-Soquel Watershed
  • San Pablo Bay Watershed
  • Santa Maria Watershed
  • Smith Watershed
  • South Fork Eel Watershed
  • Tomales-Drake Bays Watershed

Coho Salmon

Scientific Name
Oncorhynchus kisutch
Native
Native Species
Identification

Coho salmon fry taken by Lisa Thompson. Location:  Shasta River, California. Date:  4/13/2004. Fish was approximately 6.5 cm long (2.5”).
Coho salmon fry taken by Lisa Thompson. Location: Shasta River, California. Date: 4/13/2004. Fish was approximately 6.5 cm long (2.5”).

Coho salmon parr taken by Lisa Thompson. Location:  Scott River, California. Date:  11/2/2004. Fish was approximately 12 cm long (5”).
Coho salmon parr taken by Lisa Thompson. Location: Scott River, California. Date: 11/2/2004. Fish was approximately 12 cm long (5”).

Coho salmon smolt taken by Lisa Thompson. Location:  Shasta River, California. Date:  4/15/2004. Fish was approximately 15 cm long (6”).
Coho salmon smolt taken by Lisa Thompson. Location: Shasta River, California. Date: 4/15/2004. Fish was approximately 15 cm long (6”).

Coho salmon fry (top) and a Chinook salmon fry (bottom). Location:  Shasta River, California. Date:  4/13/2004. Fish were approximately 6.5 cm long (2.5”). Photo by Lisa Thompson, UC Davis.
Coho salmon fry (top) and a Chinook salmon fry (bottom). Location: Shasta River, California. Date: 4/13/2004. Fish were approximately 6.5 cm long (2.5”). Photo by Lisa Thompson, UC Davis.

Coho salmon parr (top) and a rainbow trout parr (bottom) taken by Lisa Thompson. Location:  Scott River, California. Date:  11/2/2004.
Coho salmon parr (top) and a rainbow trout parr (bottom) taken by Lisa Thompson. Location: Scott River, California. Date: 11/2/2004.

  • Large adult fish, 55-70 cm FL, 3-6 kg, 10 kg max in CA
  • Spawners: black spots on the back, dorsal fin, and upper lobe of caudal fin
  • Gums of lower jaw white or gray
  • Spawning males: dark red sides, dark green head and back, gray to black belly, strong hooked jaws and humped back
  • Spawning females: duller than males, dark pink on the sides, slight hook in jaw
  • Juveniles:
    • 8-12 narrow parr marks widely spaced along lateral line
    • Sickle shaped anal fin, leading edge longer than base, adipose fin “window-like”: dark rim, opaque center
    • Caudal, anal, and adipose fins are pale orange
  • Fin Rays: dorsal 9-12, anal 12-17, pectoral 13-16, pelvic 9-11
  • Lateral line scales: 121-148 with single pore per scale
Life History

Coho salmon, commonly referred to as silver salmon, have the southernmost distribution of the salmon species in California. Coho salmon occupy a sizeable number of streams and survive in conditions considered unfavorable or lethal to most salmon. Coho salmon hatch from eggs in the spring after months of incubation in cold gravel pockets. Now called alevin, they stay deep within the gravel to avoid predation and emerge days later as fry. Optimal growth occurs at 12-14°C and coho salmon fail to survive in streams where the temperature exceeds 22-25°C for extended periods of time. Juvenile coho salmon prefer pools and usually begin to favor higher stream velocities as they get older, occupying the midstream and stream margin areas. In situations where dissolved oxygen becomes limited young coho salmon may move to riffles and areas of turbulent water earlier in life. The majority of young coho salmon remain in their native rearing grounds, though some fish move upstream or downstream to develop in more favorable conditions. Sometimes juvenile coho salmon reside in lakes in the shallow zones near shore. Coho salmon may spend one to several years in their home stream before emigrating down to the ocean. The juvenile coho transform into smolts as they head for the Pacific Ocean in March, April or May, traveling mostly at night. Upon first arrival in the ocean the fish may stay close to the mouth of their native stream and the continental shelf, dispersing with time. Coho salmon spend an average of 18 months in the Pacific Ocean growing rapidly, though some males called “jacks” return to spawn early after only 6 months at sea. Coho salmon sometimes migrate large distances to ideal feeding grounds. The coast of California is often a premier location. Coho salmon return to their native California streams in November and December as stream flows rise and allow passage upstream to the home spawning grounds. The female usually chooses a swiftwater spot at the top of a riffle to dig several small nests or redds. North American female coho salmon produce approximately 1,500-7,000 eggs each, with California stocks typically having relatively low fecundity. Moving upstream the female will deposit her eggs into the nests as a male coho follows to fertilize. The fertilized eggs are covered and left to incubate during the cool winter months. Both the male and female coho salmon then die, though females may guard the nest for up to 14 days before perishing.

Watershed
  • Big-Navarro-Garcia Watershed
  • Bodega Bay Watershed
  • Chetco Watershed
  • Lower Eel Watershed
  • Lower Klamath Watershed
  • Mad-Redwood Watershed
  • Mattole Watershed
  • Middle Fork Eel Watershed
  • Russian Watershed
  • Salmon Watershed
  • San Lorenzo-Soquel Watershed
  • San Pablo Bay Watershed
  • Scott Watershed
  • Shasta Watershed
  • Smith Watershed
  • South Fork Eel Watershed
  • South Fork Trinity Watershed
  • Tomales-Drake Bays Watershed
  • Trinity Watershed
  • Upper Eel Watershed

Colorado Pikeminnow

Scientific Name
Ptychocheilus lucius
Native
Native Species
Identification

Colorado pikeminnow, adult, right side. Photo by Cameron T. Wilcox, Colorado State University.
Colorado pikeminnow, adult, right side. Photo by Cameron T. Wilcox, Colorado State University.

Colorado pikeminnow, adult, left side. Photo by Cameron T. Wilcox, Colorado State University.
Colorado pikeminnow, adult, left side. Photo by Cameron T. Wilcox, Colorado State University.

  • Large, up to 2 m TL
  • Long body, flattened tapered head, deeply forked tail
  • Mouth large, toothless; maxilla extends back behind front edge of eye
  • Coloration: body silvery, larger individuals dark on the back, white to yellow on sides and underside
  • Juveniles: dark spot at base of tail
  • Spawning adults: silvery on sides, gold flecks, cream colored underside
  • Breeding males develop tiny tubercles on head, and row of tubercles along the side
  • Fin rays: dorsal 9, anal 9, pectoral 14-16, pelvic 8-10
  • Lateral line scales: 76-97, 18-23 rows above lateral line
  • Pharyngeal teeth: 2,5-4,2

 

Life History

Colorado pikeminnow, formerly known as Colorado squawfish, are extinct in California and absent from the lower Colorado River drainage which they historically occupied. They are listed federally and in California as an endangered species and are only found in small numbers in the upper mainstem Colorado River and tributaries such as the Green River, Yampa River, and San Juan River. Juvenile Colorado pikeminnow live in shallow edge habitat and backwaters. They feed on aquatic invertebrates, and shift to feeding on fish as they reach 100 mm TL. Larger fish may move actively through the river, but still tend to inhabit backwaters and areas with slower currents and abundant prey. Colorado pikeminnow mature after age 6, at 430-500 mm TL, and may live to 30 years. They may make long spawning migrations of over 200 km, starting in early summer. They spawn in late June to early August in fast-flowing rapids in deep canyons where the eggs stick to the gravel substrate. Eggs hatch in 3-6 days and larvae drift downstream over 100 km to rearing habitat.

Links to Other Research
Watershed
  • Havasu-Mohave Lakes Watershed
  • Imperial Reservoir Watershed
  • Lower Colorado Watershed
  • Piute Wash Watershed

Common Carp

Scientific Name
Cyprinus carpio
Native
Non-Native
Identification

Common carp approximately 18 cm (7”) long. Location: Suisun Marsh, California. Date: 8/8/2008
Common carp approximately 18 cm (7”) long. Location: Suisun Marsh, California. Date: 8/8/2008

Common carp. Captured in the upper Feather River near Portola, CA in July 2008. Photo by Dan Worth, California Department of Fish and Game.
Common carp. Captured in the upper Feather River near Portola, CA in July 2008. Photo by Dan Worth, California Department of Fish and Game.

Common carp approximately 18 cm (7”) long. Location: Suisun Marsh California Date: 8/6/2007
Common carp approximately 18 cm (7”) long. Location: Suisun Marsh California Date: 8/6/2007

  • Heavy bodied
  • Large scales
  • Sub terminal mouth with two pairs of barbels on the upper lip
  • Juveniles have terminal mouths and smaller barbels
  • Rear barbels are longer than the front pair
  • Dorsal and anal fins have 1 large and 2 smaller serrated spines
  • Adults: gold-green to bronze in color with pectoral, pelvic, and anal fins tinged in red
  • Juveniles: brown to gray in color
  • Fin rays: dorsal 17-21 (after spines), anal 5-6 (after spines),pelvic 5-7, caudal 19
  • Lateral line scales: 32-38 (may be much less in some varieties)
Life History

Common carp are most often found in the warm, turbid waters of eutrophic lakes, reservoirs, and sloughs with silty bottoms and high vegetation growth or in turbid, alkaline streams with deep permanent pools, and soft bottoms. These are only optimal preferences however, as common carp can be found in a wide range of habitats with specimens being found in waters as cold as 4°C and as warm as 31-36°C, salinities up to 16 ppt, and dramatically low levels of dissolved oxygen (between 0.5 and 3.0 ppm). These tolerances have allowed common carp to quickly settle into lakes and streams with harsh conditions and they are often the first species to return to an area after a drought. Common carp stay in shallow areas where they forage for most of the year but will overwinter in the deeper areas of their range. They leave these secure depths in spring to root through the soil for aquatic insect larvae, small mollusks, crustaceans, and annelid worms. Newly hatched larvae feed purely on algae and zooplankton but can eat most available invertebrates by the time they are a year old. Adults will also feed on plants and algae but this appears to be less important to their diet.

As water temperatures begin to exceed 15°C in spring and early summer, large shoals of common carp will begin mating, reaching peak activity when the water is between 19°C and 23°C. This usually occurs in the late evening and early morning but can happen at any time of the day. Spawning behavior starts with a large school swimming around slowly before breaking off into smaller groups, usually one female and 2 or 3 males that swim to shallow, weedy areas to spawn. Females lay 500 eggs at a time and can lay between 50,000 and 2,000,000 in a single season. Eggs adhere to the sides of aquatic plants and hatch 3-6 days later. The 3-7 mm offspring then fall to the river bottom and feed off their yolk sack before finding cover in aquatic vegetation about a week later. They will not leave the safety of this cover until they are 7-10 cm in length. Growth is determined by a variety of factors including summer temperatures, water quality, and food abundance so by the first summer young common carp can be anywhere between 7 cm and 36 cm long but average between 10 cm and 15 cm. They will usually double in size by the second summer, and then increase by 10-12 cm annually until growth slows in the fourth or fifth year. Common carp usually live between 12 and 15 years in the wild and average a length of 80 cm and a weight of 4.5 kg. Captive individuals have been found to live up to 47 years and weights have been recorded up to 37.9 kg.

 

Links to Other Research
Watershed

Cutthroat Trout

Scientific Name
Oncorhynchus clarki
Native
Native Species
Identification

Cutthroat trout, sea-run adult. Caught along the beaches of Hood Canal near Seabeck, Washington. Photo courtesy of Larry Coté.
Cutthroat trout, sea-run adult. Caught along the beaches of Hood Canal near Seabeck, Washington. Photo courtesy of Larry Coté.

Cutthroat trout. Photo courtesy of Professor Peter B. Moyle.
Cutthroat trout. Photo courtesy of Professor Peter B. Moyle.

Cutthroat trout, sea-run adult, head. Caught along the beaches of Hood Canal near Seabeck, Washington in March 2008. Photo by Larry Coté.
Cutthroat trout, sea-run adult, head. Caught along the beaches of Hood Canal near Seabeck, Washington in March 2008. Photo by Larry Coté.

Lahontan cutthroat trout, photographed at Heenan Lake, California in October 2006. Photo by Michael Carl.
Lahontan cutthroat trout, photographed at Heenan Lake, California in October 2006. Photo by Michael Carl.

Lahontan cutthroat trout spawning pair. Independence Creek, CA. Photo courtesy of Mr. Jim Gaither, The Nature Conservancy.
Lahontan cutthroat trout spawning pair. Independence Creek, CA. Photo courtesy of Mr. Jim Gaither, The Nature Conservancy.

Lahontan cutthroat trout, Heenan Lake, CA. Photo courtesy of Gerard Carmona Catot.
Lahontan cutthroat trout, Heenan Lake, CA. Photo courtesy of Gerard Carmona Catot.

Paiute cutthroat trout. Photo courtesy of William Somer, California Department of Fish and Game.
Paiute cutthroat trout. Photo courtesy of William Somer, California Department of Fish and Game.

  • Maximum length about 1 m TL (Lahontan), smaller coastal forms in CA max around 50 cm FL
  • Red slashes of pigment underneath lower law (faint in sea-run or young
  • Well developed teeth on jaws, head, tongue, etc.
  • Many black body spots
  • Adipose fin may have few spots, dorsal fin may have black leading edge
  • Similar to rainbow trout, but cutthroat trout have:
    • More slender body
    • Larger mouth
  • Basibranchial teeth-found on bottom of throat
  • Coloration of Cutthroat sub-species:
    • Coastal: similar to rainbow, but heavier spotting, especially in posterior and ventral halves
    • Lahontan: fewer larger spots than coastal form, dark olive to reddish brown body
    • Paiute: adults retain parr marks; body and tail lack black spots; spots present on dorsal and adipose fins; copper, green, or yellowish body
  • Fin rays: dorsal 9-11, anal 8-12, pelvic 9-10, pectoral 12-15
  • Lateral line scales: 110-130

 

Life History

Cutthroat trout have two distinct forms: the anadromous form or coastal cutthroat, and the inland Paiute and Lahontan cutthroat. The coastal cutthroat trout and inland cutthroat trout are spatially separated by the width of California, and are thus quite ecologically different. Coastal cutthroat trout are found from Northern California up to Alaska. They are more strongly tied to freshwater than most of the anadromous salmonids, especially in California, and resident non-migratory populations exist. Most migration in California is limited to movement within a river system or to movement between a river and the estuary. Cutthroat trout that do enter the ocean rarely stray far from the mouth of their natal stream, and residence in saltwater is limited to summer months. Most of the cutthroat trout in California, including the non-spawning fish, return to freshwater during the winter or high flow months and hide in pools with complex forms of cover. Anadromous populations may reside in freshwater for up to five years before leaving for the ocean, where they are believed to loosely congregate in shoals. In their freshwater stages, cutthroat trout generally reside in small low-gradient streams with cool water temperatures in the range of 9-12°C and minimum dissolved oxygen levels of 5 mg/L. Juvenile fish are opportunistic feeders that rely mostly on benthic and drift insects. As freshwater cutthroat trout get larger they go from being the possible prey of other salmonids to the potential predators of other salmonids, insects, and crustaceans. In the ocean cutthroat trout continue to feed on fish and crustaceans and may broaden their diet to include new species of fish. Adult cutthroat trout will grow 5-10 cm per year with an adequate food supply in the ocean or a large river system. Spawners will not feed if they have sufficient fat storage, but will feed on insects and other forms of prey in freshwater if they need the energy. Anadromous cutthroat trout reach sexual maturity in 2-4 years and enter streams to breed with the first high flow between August and October. Female trout find reaches in their natal streams with gravel substrate, usually in pool tails. The females dig several redds and deposit eggs in succession while moving upstream. Males fertilize the eggs before the females cover the redds with gravel. Egg production increases with body size: females measuring 200-400 mm will produce an average of 1,100 to 1,700 eggs per spawning season. In California fry emerge in March-June after 6-7 weeks of incubation and a short amount of time spent as an alevin within the safety of the gravel. Cutthroat trout typically do not live longer than 7 years, with a maximum life of 10 years.

The inland forms of cutthroat trout were historically one of only two salmonids found on the eastern side of the Sierras.They are found in small to large rivers and lakes with common characteristics of cool water and adequate dissolved oxygen.Inland cutthroat trout have a wide degree of tolerance for temperature, sediment, and alkaline conditions.They have been found to live in streams where the temperature exceeds 27°C, and found in lakes with a TDS of 13,000 mg/L and a pH of 9.5.Historically they were probably found in streams with abundant food sources and with a maximum water temperature of 23°C.Inland cutthroat trout, like the coastal forms, may have varying degrees of movement or migration. A fish may spend its entire life in a 20 m reach of stream, or may move many kilometers within a lake or river network.In streams they feed on drifting and benthic insects, whereas in lakes their diet may also include zooplankton, crustaceans, snails and other fish.Growth rates are temperature and food dependent.The largest recorded Lahontan cutthroat, from Pyramid Lake, NV was 99 cm TL and weighed 18.6 kg.Paiute cutthroat trout, which are typically found in small high elevation streams, rarely exceed 25 cm FL.Inland cutthroat trout reach sexual maturity in 2-4 years.Spawning takes place in April through early July, with most Lahontan cutthroat trout moving up into tributaries of lakes and rivers to breed.Fecundity of Lahontan cutthroats is about 400 - 8,000 eggs per female, a number that grows with body size.Paiute cutthroats only produce 325 - 350 eggs per female.Lahontan cutthroat trout may spawn up to 5 times whereas Paiute cutthroat trout only spawn once in a life time.Maximum expected ages are 9 years and 3 years, respectively.The eggs hatch in 6 - 8 weeks, though the alevin remain within the substrate for up to 2 weeks before emerging into the water column.Young Lahontan cutthroat trout often move into a lake for a year while young stream dwelling cutthroat trout stay in the stream margins to feed.

Links to Other Research
Watershed
  • Applegate Watershed
  • Chetco Watershed
  • East Walker Watershed
  • Lake Tahoe Watershed
  • Lower Eel Watershed
  • Lower Klamath Watershed
  • Mad-Redwood Watershed
  • Smith Watershed
  • Truckee Watershed
  • Upper Carson Watershed
  • Upper Klamath Watershed
  • West Walker Watershed

Delta Smelt

Scientific Name
Hypomesus transpacificus
Native
Native Species
Identification

Delta Smelt, Adult (swimming), UC Davis Fish Conservation and Culture Lab, Byron, CA (largely funded by the California Department of Water Resources) May 15, 2008
Delta Smelt, Adult (swimming), UC Davis Fish Conservation and Culture Lab, Byron, CA (largely funded by the California Department of Water Resources) May 15, 2008

Delta Smelt, Adult (side view), UC Davis Fish Conservation and Culture Lab, Byron, CA (largely funded by the California Department of Water Resources) May 15, 2008
Delta Smelt, Adult (side view), UC Davis Fish Conservation and Culture Lab, Byron, CA (largely funded by the California Department of Water Resources) May 15, 2008

Delta Smelt, juvenile (swimming), UC Davis Fish Conservation and Culture Lab, Byron, CA (largely funded by the California Department of Water Resources) May 15, 2008. Note: lower half of caudal fin is torn.
Delta Smelt, juvenile (swimming), UC Davis Fish Conservation and Culture Lab, Byron, CA (largely funded by the California Department of Water Resources) May 15, 2008. Note: lower half of caudal fin is torn.

Delta Smelt, Adult (frontal left view), UC Davis Fish Conservation and Culture Lab, Byron, CA (largely funded by the California Department of Water Resources) May 15, 2008.
Delta Smelt, Adult (frontal left view), UC Davis Fish Conservation and Culture Lab, Byron, CA (largely funded by the California Department of Water Resources) May 15, 2008.

  • Small and slim, up to 120 mm SL
  • Adipose fin present
  • Large eyes, small mouth: maxilla doesn’t extend past middle of eye, small pointed teeth
  • Pectoral fins reach < 2/3 distance to pelvic fins
  • Coloration: almost translucent, sides have blue sheen
  • Dark spot rarely present between jaws
  • Fin rays: dorsal 8-11, pelvic 8, pectoral 10-12, anal 15-19
  • Lateral line scales (incomplete): 53-60
Life History

 

Delta smelt are euryhaline and primarily live in or just upstream of the mixing zone between fresh and salt water in the San Francisco Bay-Delta. Typically these upper estuarine areas are shallow and have salinities ranging from 2-7 ppt. Delta smelt live in water with salinities ranging from 0 to 18.4 ppt and can tolerate salinities up to 19.0 ppt. Suisun Bay, CA is usually the location of this mixing zone, though changes in streamflow can affect how far downstream these low salinity waters occur. Delta smelt can live in water temperatures ranging form 6 to 28°C with lethal levels at 29°C, though their success seems to have little relation to water temperatures. Smelt are short burst swimmers that feed on plankton and therefore they are typically found in places with low water velocities where the water is cool and well oxygenated. They share habitat preferences but they are not shoaling fish. Planktonic food items include copepods, cladocerans, amphipods, and insect larva. Young smelt tend to focus on immature stages of calanoid copepods while adult smelt may feed on all life stages as well as other large planktonic organisms. Delta smelt grow quickly and the growth rate is largely food dependent. The most rapid growth occurs when they reach 30 mm FL and are large enough to prey on a wider variety of food sources. In 7-9 months they reach lengths of 55-70 mm SL with growth slowing in the several months that follow. A few smelt live a second year and reach lengths of 90-120 mm SL. In spring smelt populations are dominated by spawning adults, and by summer they have died and given rise to the next generation of juveniles. Spawning occurs in upstream spawning grounds from February to July, though fish begin moving up the delta as early as September or October. Delta smelt spawn mostly at night during low tide in freshwater sloughs and shallow edge waters. In the Sacramento River fish typically spawn above Rio Vista. Smelt have also been recorded spawning in different parts of Suisun Bay and the Napa River Estuary. Females move to the bottom of the water column where they are accompanied by a male. The two swim side by side and release eggs and milt, the male fish sometimes pausing to ward off other attending males. Females lay 1,200 to 2,600 eggs depending on body size and most eggs come from the left ovary. The eggs hatch in 9-13 days at a water temperature of 14.8-16.5°C. The emergent larvae begin feeding on rotifers and minuscule prey in 4-5 days. The larvae have an oil sac that keeps them semi-buoyant till their swimbladders develop several weeks later. At that point they are capable of rising into the water column where they are washed downstream by the current into the mixing zone. The number of spawning fish is weakly or nominally associated with the number of the next generation.

Links to Other Research
Watershed
  • Lower Sacramento Watershed
  • San Joaquin Delta Watershed
  • San Pablo Bay Watershed
  • Suisun Bay Watershed

Desert Pupfish

Scientific Name
Cyprinodon macularius
Native
Native Species
Identification

Desert pupfish, male and female. Location: Borrego Springs High School Pond. Date: May 2010. Photo by Sharon Keeney, California Department of Fish and Game.
Desert pupfish, male and female. Location: Borrego Springs High School Pond. Date: May 2010. Photo by Sharon Keeney, California Department of Fish and Game.

Desert pupfish, male, breeding coloration. Location: Borrego Palm Canyon Pond, Anza-Borrego Desert State Park. Date: May 2010. Photo by Sharon Keeney, California Department of Fish and Game.
Desert pupfish, male, breeding coloration. Location: Borrego Palm Canyon Pond, Anza-Borrego Desert State Park. Date: May 2010. Photo by Sharon Keeney, California Department of Fish and Game.

Desert pupfish, female. Location: Arthur 0.5 Drain, Salton Sea. Date: Summer 2006. Photo by Sharon Keeney, California Department of Fish and Game.
Desert pupfish, female. Location: Arthur 0.5 Drain, Salton Sea. Date: Summer 2006. Photo by Sharon Keeney, California Department of Fish and Game.

Desert pupfish, male. Location: Arthur 0.5 Drain, Salton Sea. Date: Summer 2006. Photo by Sharon Keeney, California Department of Fish and Game.
Desert pupfish, male. Location: Arthur 0.5 Drain, Salton Sea. Date: Summer 2006. Photo by Sharon Keeney, California Department of Fish and Game.

Desert pupfish, adult male in breeding coloration (silver blue color). Captured from the USGS/BOR Shallow Habitat Project experimental ponds on the southeast side of the Salton Sea, CA,on 04/27/2009. Photo by Barbara A. Martin, USGS.
Desert pupfish, adult male in breeding coloration (silver blue color). Captured from the USGS/BOR Shallow Habitat Project experimental ponds on the southeast side of the Salton Sea, CA,on 04/27/2009. Photo by Barbara A. Martin, USGS.

Desert pupfish, adult female, in seine net with other fish. Captured from the USGS/BOR Shallow Habitat Project experimental ponds on the southeast side of the Salton Sea, CA on 04/27/2009. Photo by Barbara A. Martin, USGS.
Desert pupfish, adult female, in seine net with other fish. Captured from the USGS/BOR Shallow Habitat Project experimental ponds on the southeast side of the Salton Sea, CA on 04/27/2009. Photo by Barbara A. Martin, USGS.

Desert pupfish, adult male losing his breeding colors. Captured from an irrigation drain leading to the Salton Sea, CA, on 07/11/2008. Photo by Cory Emerson, USGS. Note: Scale is in centimeters.
Desert pupfish, adult male losing his breeding colors. Captured from an irrigation drain leading to the Salton Sea, CA, on 07/11/2008. Photo by Cory Emerson, USGS. Note: Scale is in centimeters.

Desert pupfish, adult female. Photographed on 05/31/2009 by Barbara A. Martin, USGS.
Desert pupfish, adult female. Photographed on 05/31/2009 by Barbara A. Martin, USGS.

  • Small, chunky, max 75 mm TL (males larger than females)
  • Circuli on large scales have spines, interspaces lack reticulations
  • Dorsal fin is equidistant from base of tail and tip of snout
  • One full row of tricuspid incisor-like teeth
  • Coloration (sexual dimorphism present):
  • Breeding male: blue with lemon yellow tail and caudal peduncle, 5-8 faint vertical bars along sides, black band on posterior end of caudal fin
  • Breeding females: tan to olive, 5-8 vertical bars more prominent
  • Fin rays: dorsal 9-12, anal 9-12, pectoral 14-18, caudal 14-20, pelvic 2-8
  • Lateral series scales: 25-26
Life History

Desert pupfish are a hearty species capable of surviving extreme environmental fluctuations. They can tolerate temperatures from 7°C up to 45°C, salinities ranging from 0 to 70 ppt, and oxygen levels from saturation down to 0.1-0.4 mg/L. Desert pupfish can live through daily temperature fluctuations of 26°C and changes in salinity of 10 to 15 ppt. Larval pupfish can survive sudden salinity changes of 35 ppt and total salinities as high as 90 ppt. Despite their adaptability, desert pupfish in California are only found in small isolated populations. Favorable waters are calm, though desert pupfish are often found in polluted and fluctuating conditions. Pupfish usually form loose shoals and tend to have a size dependent spatial distribution. In the Salton Sea smaller fish swim together in shallow zones whereas larger fish swim in deeper water. During the breeding season male fish become territorial and shoals are made up of primarily female and juvenile pupfish. In the Salton Sea desert pupfish migrations and feeding are largely temperature dependent. In the early morning and late evening pupfish forage in shallow zones. They move out of the shallows during the middle of the day when water temperatures may rise to 36°C. The diet of a desert pupfish may include algae, small invertebrates, aquatic crustaceans, aquatic insect larvae, snails, and detritus. Desert pupfish grow rapidly and can complete their life cycle in a single summer under optimal conditions. They may become sexually mature at 15 mm SL, but most don’t breed until they are at least 30-50 mm SL. At the end of one growing season they may reach a maximum total length of 45-50 mm. Spawning occurs from April to October. Spawning typically takes place when water temperatures begin to exceed 20°C. Some males defend territories and try to entice females while other males lurk along the edges waiting for a chance to fertilize. Territorial males tend to select larger females because egg production is size dependent. When a female is lured away from her shoal by a territorial male, they demonstrate a number of courtship acts before the male cups the female’s caudal peduncle with his anal fin. They shake together and the female releases a single egg. Each series of trembling acts may result in 1-4 eggs and a female may lay 50-800 eggs in a single season. Large females sometimes eat the embryos of other female pupfish. Fertilized eggs hatch in 10 days at 20°C, and the emergent larvae occupy shallow regions where they begin feeding on small invertebrates within the first day of hatching.

Links to Other Research
Watershed
  • Salton Sea Watershed

Eulachon

Scientific Name
Thaleichthys pacificus
Native
Native Species
Identification

Eulachon, male, caught in rotary screw trap  on the Sacramento River at Knights Landing on 1/27/2006. Photo by Michael S. Brown, California Department of Fish and Game. Note: Gonads were removed.
Eulachon, male, caught in rotary screw trap on the Sacramento River at Knights Landing on 1/27/2006. Photo by Michael S. Brown, California Department of Fish and Game. Note: Gonads were removed.

Eulachon, male, caught in rotary screw trap  on the Sacramento River at Knights Landing on 1/27/2006. Photo by Michael S. Brown, California Department of Fish and Game. Note: Gonads were removed and are shown below the fish.
Eulachon, male, caught in rotary screw trap on the Sacramento River at Knights Landing on 1/27/2006. Photo by Michael S. Brown, California Department of Fish and Game. Note: Gonads were removed and are shown below the fish.

  • Largest of North American smelt, 20-30 cm TL
  • Elongated body, laterally compressed: depth 15-20% of TL
  • Large mouth: maxilla reaches middle to past rear margin of eye, small pointed teeth
  • Pectoral fins reach about 2/3 of way to bases of pelvic fins
  • Gill covers with concentric striations
  • Brown to dark blue back and head, silver to white underside, unmarked fins
  • Spawning adults: may lack pointed teeth on jaw
  • Males: mid-lateral ridge present, breeding tubercles on head, body, fins
  • Females: may have undeveloped breeding tubercles
  • Fin rays: dorsal 10-13, pelvic 8, pectoral 10-12, anal 18-23
  • Lateral line scales: 70-78 (complete)
  • Very oily flesh
Life History

 

Eulachon are anadromous and spend the majority of their lives in the ocean and return back to coastal freshwater streams to spawn and die. Most eulachon live 3 years though some fish are actually repeat spawners and live to age 5. When eulachon first hatch, the larvae are washed downstream towards the sea, and they don’t become free swimming juveniles until they have reached a total length of 50-80 mm. In the ocean eulachon live and feed in both shallow and deep water areas, focusing their diet on copepods, euphausid shrimp, and other crustaceans. Most eulachon reach sexual maturity after 3 years and enter their natal streams between December and May. In California spawning starts in mid-March and lasts through May in the northern part of the state. Spawning migration occurs in a narrow window of 4-8°C, and may slow or stop if the water temperature rises above or falls below the favorable range. Eulachon rarely swim further than 10-12 km upstream, and males are typically first to arrive at the spawning grounds which are typified by gravel, sand, wood, and other debris. Actual breeding occurs on a large scale at night when many females deposit an average of 25,000 eggs each. The eggs have two membranes, the first of which ruptures on the substrate to anchor the remaining embryo to the streambed. Embryos generally hatch in 2-3 weeks, with a greater incubation time for eggs in cold water.

Links to Other Research
Watershed
  • Lower Klamath Watershed
  • Mad-Redwood Watershed
  • Sacramento-Stone Corral Watershed
  • Smith Watershed

Fathead Minnow

Scientific Name
Pimephales promelas
Native
Non-Native
Identification

Fathead minnow, males in breeding colors. Location: Pond in mountains above Anza, CA. Date: 2012. Photo by Michael McGrady. Note tubercles on snout.
Fathead minnow, males in breeding colors. Location: Pond in mountains above Anza, CA. Date: 2012. Photo by Michael McGrady. Note tubercles on snout.

Fathead minnow, males in breeding colors. Location: Pond in mountains above Anza, CA. Date: 2012. Photo by Michael McGrady. Note 2 pale vertical bars.
Fathead minnow, males in breeding colors. Location: Pond in mountains above Anza, CA. Date: 2012. Photo by Michael McGrady. Note 2 pale vertical bars.

Fathead minnow. Photo by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.
Fathead minnow. Photo by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.

 

  • Chunky body with an oblique mouth and a crowding of scales behind the head
  • Head is short, blunt, and broad on top
  • Breeding males have conspicuous tubercles on the snout, chin, and pectoral fins and a spongy pad on the back of the head
  • Dark brown or olive back, with dull and dusky sides, often with black peritoneum showing through
  • Scales are outlined in pigment on the back
  • Breeding males turn completely black except for two wide, pale, vertical stripes on their sides.
  • Small fish or fish from turbid waters may be pale whitish to silvery
  • 8 dorsal, 8 pelvic, and 7 anal fin rays
  • First dorsal fin is thickened
  • 44-54 scales in the lateral line which rarely extends beyond the anterior half of the body
Life History

The fathead minnow is a species that thrives in areas where other fish have trouble establishing. Fathead minnows can withstand alkalinities higher than 2,100 mg/L, dissolved oxygen levels lower than 1 mg/L and temperatures between 7°C and 33°C. Most commonly this means fathead minnows settle in pools of small, muddy streams or in ponds with limited interspecific competition but they can also excel in intermittent streams, vernal pools, and other temporary water bodies. To endure these harsh environments, fathead minnows are very opportunistic eaters, taking whatever filamentous algae, diatoms, small invertebrates, and even loose organic matter they can find on the bottom using their long intestine and grinding teeth to digest the difficult materials. In areas where predation is a risk fathead minnows will stay close to aquatic vegetation beds and use their strong sense of smell to detect potential threats.

Spawning age is quite variable, but in California an individual’s first summer, when temperatures are between 15°C and 32°C, is a common maturing point. Males are territorial, aggressively defending and carefully cleaning a submerged board, stone, root mass, old tire, or any other surface that eggs can be hung underneath. Interestingly, the same head pad that males use to clean the nest surface is also used to secrete a mucus on the developing embryos that is believed to improve the young’s chances of survival. Once males have established their territories, females will leave their school to judge the male’s nest and courtship display. If the male is successful the female will attach her adhesive eggs to the underside of the nest object where the male will then fertilize them. Females can hold 600-2,300 in their body at once but at any given time only a third of those eggs will be ripe. Fathead minnows mate multiple times throughout the summer however, and females will potentially lay more than 4,100 eggs by the end of the season. Both sexes have several partners during the spawning season leading to nest sites that have more than 12,000 embryos in various stages of development under a single male’s care. Eggs hatch 4-6 days later at 25°C and the 4.8 mm-long larvae will stay under the nest for several more days after hatching. Their growth will be influenced by a variety of factors, including population size, temperature, and food availability, but in general they will reach 84 mm in length by the end of one year. Most do not live past this age and adults usually die within 30-60 days of spawning. The maximum age and length recorded is 3 years and 109 mm respectively.

Links to Other Research
Watershed

Flathead Catfish

Scientific Name
Pylodictis olivaris
Native
Non-Native
Identification

Flathead catfish, adult. Caught in the St. Croix River, Washington County, Minnesota, in summer 1976. Photo by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.
Flathead catfish, adult. Caught in the St. Croix River, Washington County, Minnesota, in summer 1976. Photo by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.

Flathead catfish, young-of-the-year. Photo by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.
Flathead catfish, young-of-the-year. Photo by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.

  • Elongate, slender body with an extremely large and flat head and small eyes located towards the top.
  • Slightly indented, rounded tail
  • Terminal mouth with lower jaw projecting beyond the upper jaw.
  • Maxillary barbels are just larger than the head
  • Pale blue to olive on the sides and white on the belly
  • 14-17 rays in the rounded anal fin
  • Large, projecting adipose fin
  • Rough spine in pectoral fins
  • Black when young, then become olive with brown mottling on the back and sides, and finally become a plain olivaceous yellow-brown
  • Yellow to white patch on the upper lobe of the tail
  • Males have a distinct genital papilla with an opening at the tip while females have a smaller recessed papilla and a longitudinal slit for the urogenital openings
Life History

Flathead catfish are most commonly found in large, turbid rivers with temperatures between 24°C and 34°C. Adults spend their days alone, resting on the bottom of deep pools or hiding under debris in faster moving areas before moving into the shallow areas to feed at night. Their large flat head makes them well suited for a sit-and-wait hunting strategy, staying very still until prey moves close enough to be engulfed by their large mouth. Small catfish feed mainly on small insect larvae but will shift towards crayfish and fish as they get older. Males mature by 3-5 years of age or when they are about 38 cm long while females mature in 4-6 years or by 46 cm in length. Spawning occurs between May and early July when temperatures exceed 22-24°C. Both male and female work to construct a nest by either creating a new depression in the stream bottom or clearing away a previously submerged hole. After a courtship ritual where the male repeatedly rubs against his mate, the female will lay between 30 and 35 eggs into the nest and then move on to nest with another male elsewhere. In a single season females can lay anywhere between 4,000 and 59,000 eggs. The males will stay with the nest, protecting and fanning the eggs to maximize their oxygen levels until hatching. The young quickly become free swimming but stay together in a tightly packed ball protected by their father until they reach a safe enough size to depart and hide in riffles where rocks and complex debris can be used as cover. When one year old they will be between 11 cm and 12 cm in length and by age 8 they may be as large as 93 cm. It is possible for flathead catfish to live to be 19 years and obtain sizes greater than 1.4 m and weights greater than 45 kg, and fish weighing 9-13 kg are not uncommon in the lower Colorado River.

Links to Other Research
Watershed

Golden Shiner

Scientific Name
Notemigonus crysoleucas
Native
Non-Native
Identification

Golden shiner, caught in Iron Gate Reservoir, California on 12 May 2009 by Teejay O'Rear. Photo by Amber Manfree.
Golden shiner, caught in Iron Gate Reservoir, California on 12 May 2009 by Teejay O'Rear. Photo by Amber Manfree.

Golden shiner. Caught and released in the South Fork Mokelumne River, San Joaquin County, 25 Oct 2013. Photo by Gary Riddle.
Golden shiner. Caught and released in the South Fork Mokelumne River, San Joaquin County, 25 Oct 2013. Photo by Gary Riddle.

  • Deeply compressed body with a small head, pointed snout, and upward pointing mouth
  • Deciduous scales but scaleless on the keel between pelvic fins and anus
  • Usually golden in sheen but many also have a silvery color, especially smaller fish
  • Fins are colorless except for breeding males which have a red-orange tinge on the pelvic and anal fins
  • 11-14 anal, 9 pelvic, 15 pectoral, and 7-9 dorsal fin rays
  • Dorsal fin starts behind the pelvic fins
  • Lateral line with 44-54 scales curves downward from the head
Life History

 

Golden shiners are commonly found around aquatic vegetation in warm, shallow ponds and lakes and are especially common in low elevation reservoirs and sloughs. They can survive in temperatures up to 36°C and in water with dissolved oxygen levels less than 1 mg/L. Occasionally they find habitat in cold water lakes but only if there is a warm breeding area nearby. Golden shiners are visual predators powered by a streamlined body and maneuverable fins. They use this agility to seek out and attack their prey bothin midwater and at the surface. They are adapted to both picking off large zooplankton individually and filter feeding for smaller zooplankton species. While this allows for a fair amount of variety in food choices, Daphnia and small flying insects plucked from the surface make up the bulk of an individual’s diet. Larger golden shiners may also eat small fish, mollusks, and aquatic insect larvae. If food is scarce, golden shiners have also been found to eat algae. Given their visual hunting style golden shiners are generally active during the day except in areas of high predation risk where they will school together in pelagic and littoral areas during daylight hours and only forage when it is too dark for their predators to hunt.

Spawning occurs between March and September when water temperatures reach 20°C. Mating takes place in early morning shoals as females swim over submerged debris to deposit between 2,700-4,700 sticky eggs per season. Males follow behind in the school waiting to fertilize the eggs as soon as the female drops them. Occasionally the nests of largemouth bass are used as an egg drop point and it is believed that these larvae are protected by the bass resulting in a higher chance of survival. Regardless of nest site, the young will hatch 4-5 days later in temperatures between 24°C and 27°C. This new generation will school together in large numbers around aquatic vegetation near shore. Here they will begin eating small rotifers and epiphytic algae but soon shift to a more crustacean-based diet. In a year they will have grown to between 36 mm and 46 mm in length if the water is cold, but they can reach 76 mm in warmer waters. By their second year golden shiners can grow to lengths of 140 mm but at this point their growth rate declines dramatically. The oldest and largest individuals recorded were 9 years old and 260 mm respectively.

Links to Other Research
Watershed

Golden Trout

Scientific Name
Oncorhynchus mykiss subspecies
Native
Native Species
Identification

Golden trout (Kern River rainbow trout), photographed on the North Fork of the Kern River in the Funston Meadow section of the Kern Canyon, 08/19/09. Photo by Michael Carl.
Golden trout (Kern River rainbow trout), photographed on the North Fork of the Kern River in the Funston Meadow section of the Kern Canyon, 08/19/09. Photo by Michael Carl.

California golden trout , photographed on Golden Trout Creek near Big Whitney Meadow, 09/26/09. Photo by Michael Carl.
California golden trout , photographed on Golden Trout Creek near Big Whitney Meadow, 09/26/09. Photo by Michael Carl.

Golden trout caught in Guitar Lake,  7/16/05. Length: 21 cm. Photo courtesy of Howard Kern.
Golden trout caught in Guitar Lake, 7/16/05. Length: 21 cm. Photo courtesy of Howard Kern.

Golden trout, juvenile. Photo taken by Gerard Carmona Catot.
Golden trout, juvenile. Photo taken by Gerard Carmona Catot.

  • Adult size: in streams up to 19-20 cm SL, in lakes up to 35-43 cm FL, max 71 cm TL (5.0 kg)
  • Bright coloration: dark olive-green back; golden lower sides; bright red to orange cheeks, underside, and brachiostegals
  • Parr marks are present even in adults: about 10, centered on lateral line
  • Large spots on tail and dorsal fin, variable spotting on back (Kern River subspecies heavily spotted)
  • Orange color on pectoral, pelvic, and anal fins; pelvic and anal fins have black band followed by white-yellow tip
  • Dorsal fin with white to orange tip
Life History
California's official state fish is the California golden trout. California has three distinct subspecies of rainbow trout commonly grouped as golden trout: Kern River rainbow trout, Little Kern golden trout, and California golden trout. Today Kern River rainbows are found in the Kern River between Durrwood Creek and Junction Meadow, though other transplanted populations exist. Little Kern golden trout are still found in their native habitat in the Little Kern River. California golden trout are found in their natal streams of Golden Trout Creek and the South Fork Kern River and in addition have been transplanted to many other isolated lakes and locations for the purpose of sportfishing. Generally these new waters are at high elevations and may include stretches of stream above impassible fish barriers. Many of these transplanted golden trout hybridize with hatchery reared coastal rainbows. Native habitat for golden trout is primarily found at high elevations in meandering streams with little riparian vegetation. The water is generally clear and cold (3-22°C) and substrates are composed of cobble, gravel, and sand. Favorable reaches include pools that provide cover in the forms of undercut banks and aquatic vegetation. Individual golden trout tend to remain in a small stretch of stream measuring 16-18 m. Golden trout feed both day and night on a wide variety of items, especially aquatic insects. Cryptic coloration or a lack of predators may account for their feeding habits. Despite increased vulnerability to birds and mammals, males develop especially bright colors during the breeding season. Golden trout may live up to 9 years, reaching 10-11 cm SL by the end of their third summer. Their growth rate slows to 1-2 cm/year thereafter and they may eventually reach 19-20 cm SL. Lake dwelling golden trout arriving via transplants grow more rapidly and reach greater maximum sizes. Golden trout reach sexual maturity in 3-4 years and spawn in late spring or early summer when water temperatures range from 10-15°C. Spawning peaks in the afternoon when water temperatures reach their daily maximum. Females dig wide shallow redds among small gravel particles and lay 300-2,300 eggs. The eggs hatch in approximately 20 days at 14°C. Emergent fry remain in the substrate for 2-3 weeks before rising into the main water column.
Please see the Rainbow Trout page for more general information about rainbow trout.
Golden Trout poster (jpg). Provided courtesy of CalTrout, with permission from US Forest Service and Joseph Tomelleri.
Golden Trout poster (jpg). Provided courtesy of CalTrout, with permission from US Forest Service and Joseph Tomelleri.
This Golden Trout poster with illustrations by Joseph Tomelleri and a habitat map was provided courtesy of CalTrout, with permission from the US Forest Service (Sequoia National Forest) and Joseph Tomelleri. Collaborators also included the California Department of Fish and Game, US Fish and Wildlife Service, and Trout Unlimited.  The poster is available in high resolution pdf format as a free download by clicking the link below.  Please note, the pdf file is about 10 MB.
Links to Other Research
Watershed
  • South Fork Kern Watershed
  • Upper Kern Watershed

Goldfish

Scientific Name
Carassius auratus
Native
Non-Native
Identification

Goldfish, captured in rotary screw trap on Sacramento River at Knight's Landing. Date: January 2009. Photo by Dan Worth, California Department of Fish and Game.
Goldfish, captured in rotary screw trap on Sacramento River at Knight's Landing. Date: January 2009. Photo by Dan Worth, California Department of Fish and Game.

  • Deep, heavy body with a rounded belly
  • Can vary greatly in color but are most commonly olive on their back, silvery to shiny bronze on their sides, white to yellow on their belly, and dusky on the fins
  • 15-21 dorsal, and 5-6 anal fin rays
  • First three dorsal rays are hardened into serrated spines
  • 25-31 large scales on the lateral line
  • Breeding males develop small tubercles on the sides of their head and pectoral fins

 

Life History

 

Goldfish, most commonly thought of as a fishbowl species, are also found in wild populations mainly in fertile farm and small backyard ponds, warm water reservoirs, sloughs with heavy vegetation, and areas that are heavily disturbed or polluted. While they can physically withstand temperatures as low as freezing and as high as 41°C they are only naturally found in waters between 27°C and 37°C with mild winters. Occasionally populations become established in cold oligotrophic lakes but only if there is a large, warm littoral area available for breeding. It is rare to find goldfish in streams but some will inhabit deep riverine pools below reservoirs if there is abundant plant cover or high turbidity levels. Goldfish use their long intestine to feed heavily on difficult-to-digest algae and organic detritus, but will also catch zooplankton and aquatic macrophytes. Young goldfish feed more on zooplankton and will also include aquatic insects in their diet.

Goldfish reach sexual maturity by at least age 3 or 4, with most males becoming mature between ages 2 and 3. In order for spawning to occur water temperatures must be between 16°C and 26°C. Outside of this range, development of both adult gonads and fertilized embryos will be impaired. In California this period will begin in April or May and mating occurs around dawn on sunny days. A male will follow behind a female as she swims and fertilize the eggs as soon as they are released. These fertilized eggs then attach to the vegetation, roots, or other submerged objects below. Being serial spawners, the amount of eggs a female can hold varies dramatically with some estimates placing it between 8,000 and 72,000 eggs at a time. A female will not lay these all at once however, and only deposits 2,000 to 4,000 each time she mates. This allows for egg generation during the spawning season and eventually leads to a total fecundity of 160,000-380,000 eggs over the course of the summer. These eggs hatch 5-7 days later and the new larvae will quickly disperse in search of the protective cover of heavy vegetation. Their growth will depend largely on environmental factors, especially overcrowding, and by the end of their first season young goldfish can be anywhere between 15 mm and 105 mm long. Goldfish are a generally long lived species commonly surviving for 6 to 8 years but potentially living for as long as 30 years. They may also grow to a fair size in this time but any fish larger than 40 cm is likely a carp hybrid.

Links to Other Research
Watershed

Grass Carp

Scientific Name
Ctenopharyngodon idella
Native
Non-Native
Identification

Grass carp. Photographed on 05/13/08, by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.
Grass carp. Photographed on 05/13/08, by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.

  • Moderately slender but solid body with a wide scaleless head and terminal mouth
  • Large scales outlined in black and most with a black spot at their base
  • Silvery white appearance with occasionally olive back and sides, a gray head, a white to yellow belly, and dark fins
  • Short spineless dorsal fin with its origin in front of the pelvic fin
  • 8 dorsal, 9 anal, 18-20 pectoral, and 8 pelvic fin rays
  • 34-45 scales on the lateral line
Life History

Grass carp are most common in the backwaters and shallow areas of large, temperate river systems but can also be found in ponds, irrigation canals, and lakes. They are incredibly resilient to extreme conditions, capable of living in temperatures anywhere between freezing and 39°C, water with dissolved oxygen levels less than 1 mg/L, and in salinities higher than 17 g/L. Grass carp are an omnivorous species but plants make up the majority of their diet and become even more dominant as individuals get larger. Submerged macrophytes and other soft plants are the grass carp’s meal of choice but they will eat the entirety of whatever plants are available before moving on to invertebrates like crustaceans and clams. This is an interesting behavior because their intestine is short and poorly adapted to digest this difficult material. Instead grass carp are forced to feed constantly in order to get the nutrients they need from these plants. Grass carp will travel as much as hundreds of kilometers before establishing in an area that is rich enough in food to support their diet. Juveniles are not as dependent on plants and instead feed mainly on aquatic invertebrates from both the bottom and the plankton-rich midwater. This lasts until they reach 3-4 cm in length at which point they begin focusing on plant material instead.

Grass carp will mature at various rates depending on temperature but, in general, they will be ready to spawn by they time the reach 60-70 cm in length and 4-5 kg in weight. Mating begins in summer when temperatures exceed 18°C and water levels begin to rise. Females will then find an area of moderate current to deposit their suspended eggs for the school of following males to fertilize. Females will lay anywhere between 237,000 and 1.7 million eggs in a single season depending on their size. These eggs hatch into pelagic larvae which will soon transform into juveniles and swim to shallow water. Over the next 4 years they will grow between 36 cm and 40 cm, add another 6-7 cm for each of the next 3 years, and 2-5 cm per year after that. Some may grow more in weight than their length would suggest and individuals have been found to weigh over 5 kg in only two years. It is not uncommon for these fish to live for up to 15 years and grow to lengths of 1-1.5 m and weights of 30-36 kg.

Links to Other Research
Watershed

Green Sturgeon

Scientific Name
Acipenser medirostris
Native
Native Species
Identification

Green sturgeon, juvenile, in tank. Photo courtesy of Dennis Cocherell, UC Davis.
Green sturgeon, juvenile, in tank. Photo courtesy of Dennis Cocherell, UC Davis.

Green sturgeon, juvenile, on measuring board. Photo courtesy of Dennis Cocherell, UC Davis.
Green sturgeon, juvenile, on measuring board. Photo courtesy of Dennis Cocherell, UC Davis.

Green sturgeon, larvae, side view. Photo courtesy of Dennis Cocherell, UC Davis.
Green sturgeon, larvae, side view. Photo courtesy of Dennis Cocherell, UC Davis.

Green sturgeon, larvae, dorsal view. Photo courtesy of Dennis Cocherell, UC Davis.
Green sturgeon, larvae, dorsal view. Photo courtesy of Dennis Cocherell, UC Davis.

Green sturgeon, larvae, ventral view. Photo courtesy of Dennis Cocherell, UC Davis.
Green sturgeon, larvae, ventral view. Photo courtesy of Dennis Cocherell, UC Davis.

Green sturgeon, larvae, swimming. Photo courtesy of Dennis Cocherell, UC Davis.
Green sturgeon, larvae, swimming. Photo courtesy of Dennis Cocherell, UC Davis.

  • Large fish, up to 270 cm TL max (175 kg), over 2 m or 70 kg uncommon
  • Heterocercal tail, upper lobe longer
  • Ventral mouth, protruding vacuum lips
  • Barbels on ventral side of snout, closer to mouth than tip of snout, possess spiracle
  • Have bony plates called scutes instead of scales, plate numbers:
    • Dorsal row: 8-11
    • Lateral rows: 23-30
    • Bottom rows: 7-10
  • Large scute behind dorsal and anal fin
  • Olive green body, olivaceous lateral strip, scutes pale relative to body
  • Fin rays: dorsal 33-36, anal 22-28
Life History

 

Green sturgeon are an anadromous fish with limited distribution in California. Historically the Klamath and Sacramento River systems had the greatest spawning populations of these fish. Today the Klamath River and its tributaries are home to the largest remaining spawning populations. The Eel River and South Fork Trinity had spawning populations at one time, though they are seemingly non-existent now. The lower reaches of the San Joaquin may have also had spawners at one time. Green sturgeon have been observed as visitors in the Mad River, Smith River, and Salmon River.

 

Green Sturgeon are anadromous though they are considered the most marine of the sturgeon species and their life in freshwater may be relatively limited. Green sturgeon hatch in freshwater and may leave as yearlings or stay in a river for up to 3 years. Most juveniles migrate downstream during the summer and fall of their second year. The juvenile fish usually remain in the estuary for a period before dispersing into the Pacific. Green sturgeon are benthic feeders that use their barbels and protruding ventral mouth to find prey. In the estuary sturgeon may feed on amphipods, opossum shrimp, clams, or anchovies. The diet of a sturgeon in the ocean may include sand lances and callianassid shrimp. Sturgeon also feed on other fish. They grow at a rate of approximately 7 cm per year until they reach maturity which is typically at an age of 15-20 years. Green sturgeon spend 3-13 years in the ocean before returning to their natal streams. Males tend to spend less time at sea than females, and they mature earlier in life. Mature males do not become as large as mature females of the same age. Green sturgeon of the Klamath River begin moving upstream in late February to late July and spawning takes place between March and July. Sturgeon spawning occurs above cobble in deep, fast water. Each female produces 60,000 to 140,000 eggs which presumably hatch after only 200 hours of incubation time. Green sturgeon have been documented as living up to 42 years, though some fish biologists believe they may have a maximum life span of 60-70 years.

Links to Other Research
Watershed
  • Coyote Watershed
  • Lower American Watershed
  • Lower Butte
  • Lower Cosumnes-Lower Mokelumne Watershed
  • Lower Eel Watershed
  • Lower Feather Watershed
  • Lower Klamath Watershed
  • Lower Sacramento Watershed
  • Lower Yuba Watershed
  • Middle San Joaquin-Lower Merced-Lower Stanislaus Watershed
  • Sacramento-Lower Thomes Watershed
  • Sacramento-Stone Corral Watershed
  • Salmon Watershed
  • San Francisco Bay Watershed
  • San Joaquin Delta Watershed
  • San Pablo Bay Watershed
  • South Fork Trinity Watershed
  • Suisun Bay Watershed
  • Trinity Watershed

Green Sunfish

Scientific Name
Lepomis cyanellus
Native
Non-Native
Identification

Green sunfish with measurements Location: Leonard Lake, California Date: 8/6/2008 Photo: Lisa Thompson
Green sunfish with measurements Location: Leonard Lake, California Date: 8/6/2008 Photo: Lisa Thompson

Green sunfish with measurements Location: Leonard Lake, California Date: 8/6/2008
Green sunfish with measurements Location: Leonard Lake, California Date: 8/6/2008

Green sunfish and bluegill with measurements Location: Leonard Lake, California  Date: 8/6/2008 Photo: Lisa Thompson
Green sunfish and bluegill with measurements Location: Leonard Lake, California Date: 8/6/2008 Photo: Lisa Thompson

  • Very stout and slightly deep body
  • Rounded pectoral fins
  • Larger terminal mouth has maxillae that extend past the front margin of the eye
  • Short stiff opercular flaps
  • 10-12 dorsal, 8-10 anal, 5 pelvic, and 13-15 pectoral fin rays
  • 9-11 dorsal, 3 anal, and 1 pelvic spine(s)
  • Dark olive on back becoming lighter on the sides, often with iridescent green flecks and colored stripes
  • Yellow-orange breast and belly, iridescent green stripes on the cheek
  • Dorsal and anal fins have a dark blotch on their soft-rayed portion
  • Young show fine, closely spaced chains of iridescent blue green grid
  • Back, sides, and fins of breeding males turn dark along with yellow margins on the fins
Life History

 

Green sunfish are most common in small, warm streams with turbid, mud-bottom pools and aquatic vegetation, and are especially prevalent in streams that are intermittent in summer. They can also be found in ponds and large lakes in shallow weedy areas that are ill-suited to larger predators. This is important because green sunfish tend to do very poorly in areas with multiple fish species, especially bass. In contrast, areas that are disturbed and inhospitable to less tolerant fish support a community dominated by the green sunfish. They will often be found in small populations in deep, bedrock-lined pools of undisturbed streams, poised to invade the channel itself if the habitat is altered. This ability to thrive in disturbed streams is aided by their tolerance of temperatures greater than 38°C, dissolved oxygen levels less than 1 mg/L and alkalinities up to 2,000 mg/L. Their one major restriction seems to come from salinity as they avoid waters with salinity greater than 1-2 ppt. They are also an aggressive species with territorial feeding ranges that continually force young green sunfish into new areas. They are opportunistic predators, feeding primarily on invertebrates and small fish. Young of the year feed mainly on zooplankton, small benthic invertebrates, and the larvae of other fish, but, as they grow, the focus of their diet switches towards large aquatic and terrestrial insects, crayfish, and other fish.

 

Green sunfish mature at the beginning of their third year when they reach approximately 5-7 cm in length. Mating occurs between May and August, with the most prolific period in May and June. The preferred spawning areas are 4-50 cm deep with fine gravel bottoms near overhanging bushes or other cover. Here males will construct nests 15-38 cm in diameter while females circle the area in schools. When one is ready to spawn she will descend towards the nests and a group of males will begin courting her immediately. Once a male is selected the pair will return to his nest for a mating ritual where the female turns on her side to release eggs while the male remains upright. This creates a position where the male is perpendicular to the female, connected near their genital openings, so that the eggs can be fertilized as they are released. Both sexes have multiple mates with each female capable of laying 2,000-10,000 eggs a season depending on her size.

 

Fertilized eggs adhere to the substrate of the nest where the male will guard them for 5-7 days, at which point the eggs have hatched and the offspring have become free swimming. These young fish will be planktonic for a few days before settling into the local vegetation. They will grow to 3-5 cm in their first year and 8-13 cm SL by their third year. Green sunfish can live to be 10 years old and as long as 30 cm but this only occurs under optimal, less competitive conditions; many 4-5 year old fish only measure 8-10 cm.

Links to Other Research
Watershed

Hardhead

Scientific Name
Mylopharodon conocephalus
Native
Native Species
Identification

Hardhead, adult, right side. Location: Center for Aquatic Biology and Aquaculture, UC Davis. Date: 17 May 2007. Photo by Dave Giordano, Ecosite Media.
Hardhead, adult, right side. Location: Center for Aquatic Biology and Aquaculture, UC Davis. Date: 17 May 2007. Photo by Dave Giordano, Ecosite Media.

Hardhead, adult. Photo courtesy of Dennis Cocherell, UC Davis.
Hardhead, adult. Photo courtesy of Dennis Cocherell, UC Davis.

Hardhead. Location: Feather River. Date: 19 April 2010. Note the size of the mouth, which is smaller than that of a Sacramento pikeminnow. Photo by Lisa C. Thompson.
Hardhead. Location: Feather River. Date: 19 April 2010. Note the size of the mouth, which is smaller than that of a Sacramento pikeminnow. Photo by Lisa C. Thompson.

Hardhead, juvenile. Photo courtesy of Dennis Cocherell, UC Davis.
Hardhead, juvenile. Photo courtesy of Dennis Cocherell, UC Davis.

  • Large minnows, sometimes greater than 60 cm SL, rarely exceed 30 cm in smaller streams.
  • Slightly deeper bodied than Sacramento pikeminnow
  • Less pointed snout than Sacramento pikeminnow
  • Maxilla doesn’t extend past front margin of eye, has frenum (bridge of skin) connecting upper lip to snout (Sacramento pikeminnow lacks a frenum)
  • Coloration: brown or dusky bronze back, silvery sides
  • Young fish silver in color
  • Breeding males may develop white tubercles along snout and laterally along body
  • Fin rays: dorsal 8, anal 8-9
  • Lateral line scales: 69-81
Life History

Hardhead are typically found in small to large streams in a low to mid-elevation environment. Hardhead may also inhabit lakes or reservoirs. All ages are omnivores though the juvenile and adult fish have a slightly different diet and tooth structure for feeding. In general these fish will eat benthic invertebrates, aquatic plants and algae, or insects. The young fish typically feed on mayfly and caddisfly larvae, as well as small snails. Older fish may focus on plants, crayfish, and larger invertebrates. In a lake environment the fish may also feed on zooplankton. Within a stream hardhead tend to prefer warmer temperatures than salmonids and they are often found associated with pikeminnows and suckers. Their preferred stream temperature might easily exceed 20ºC, though these fish do not favor low dissolved oxygen levels. Therefore the hardhead minnow is usually found in clear deep streams with a slow but present flow. Most hardhead reach sexual maturity at 3 years and spawn in the spring around April-May, though spawning may take place as late as August. In small streams hardhead tend to spawn near their resident pools, while fish in larger rivers or lakes often move up to 30-75 km to find suitable spawning grounds. Though spawning may occur in pools, runs, or riffles, the bedding area will typically be characterized by gravel and rocky substrate. Females usually produce 7,000-24,000 eggs per year, though some fisheries biologists believe that the eggs may take two years to develop within the female. Upon hatching, young larval hardhead remain under vegetative cover along stream or lake margins. As the juveniles grow they may move to deeper water or be swept downstream to larger rivers below. Adult hardhead may live up to 9 or 10 years.

Links to Other Research

Temperature Preference and Tolerance of Hardhead Minnows research project webpage.

Thompson, L.C., N.A. Fangue, J.J. Cech, Jr., D.E. Cocherell, and R.C. Kaufman.  2012. Juvenile and adult hardhead thermal tolerances and preferences: Temperature preference, critical thermal limits, active and resting metabolism, and blood-oxygen equilibria. Center for Aquatic Biology and Aquaculture Technical Report, University of California, Davis. Download

 

Watershed
  • Cottonwood Headwaters Watershed
  • Honcut Headwaters Watershed
  • Lower American Watershed
  • Lower Bear Watershed
  • Lower Butte
  • Lower Cache Watershed
  • Lower Calaveras-Mormon Slough Watershed
  • Lower Cosumnes-Lower Mokelumne Watershed
  • Lower Cottonwood Watershed
  • Lower Feather Watershed
  • Lower Pit Watershed
  • Lower Sacramento Watershed
  • Lower Yuba Watershed
  • McCloud Watershed
  • Middle Fork Feather Watershed
  • Middle Kern-Upper Tehachapi-Grapevine Watershed
  • Middle San Joaquin-Lower Chowchilla Watershed
  • Middle San Joaquin-Lower Merced-Lower Stanislaus Watershed
  • Mill Watershed
  • Mill-Big Chico Watershed
  • North Fork American Watershed
  • North Fork Feather Watershed
  • Russian Watershed
  • Sacramento Headwaters Watershed
  • Sacramento-Lower Cow-Lower Clear Watershed
  • Sacramento-Lower Thomes Watershed
  • Sacramento-Stone Corral Watershed
  • Sacramento-Upper Clear Watershed
  • San Francisco Bay Watershed
  • San Joaquin Delta Watershed
  • South Fork American Watershed
  • South Fork Kern Watershed
  • Suisun Bay Watershed
  • Tulare-Buena Vista Lakes Watershed
  • Upper Bear Watershed
  • Upper Butte
  • Upper Cache Watershed
  • Upper Calaveras Watershed
  • Upper Chowchilla-Upper Fresno Watershed
  • Upper Coon-Upper Auburn Watershed
  • Upper Cosumnes Watershed
  • Upper Cow-Battle Watershed
  • Upper Dry Watershed
  • Upper Elder-Upper Thomes Watershed
  • Upper Kaweah Watershed
  • Upper Kern Watershed
  • Upper King Watershed
  • Upper Merced Watershed
  • Upper Mokelumne Watershed
  • Upper Pit Watershed
  • Upper Poso Watershed
  • Upper Putah Watershed
  • Upper San Joaquin Watershed
  • Upper Stanislaus Watershed
  • Upper Stony Watershed
  • Upper Tuolumne Watershed
  • Upper Yuba Watershed

Hitch

Scientific Name
Lavinia exilicauda
Native
Native Species
Identification

Hitch. Photo by Richard Macedo, California Department of Fish and Game.
Hitch. Photo by Richard Macedo, California Department of Fish and Game.

Hitch adult. Photo courtesy of Professor Peter B. Moyle.
Hitch adult. Photo courtesy of Professor Peter B. Moyle.

  • Deep, laterally compressed body, may exceed 35 cm SL
  • Large scales, small head, upturned mouth
  • Narrow caudal peduncle, large anal fin, large forked tail, keel absent
  • Brownish yellow back, no spot, progressively darker with age
  • Juveniles: silvery, possess spot
  • Fin rays: anal 11-14, dorsal 10-13
  • Lateral line scales: 54-62 (decurved)
Life History

Hitch are most often found in slow warm water, including lakes and quiet stretches of rivers. Hitch are sometimes found in cool and clear, low-gradient streams, hiding among aquatic vegetation in sandy runs or pools. They are the most heat tolerant of the native Central Valley fishes and can withstand water temperatures greater than 30°C under some conditions. They have also been found living in brackish water with salinities as high as 9 ppt. Within a pristine system hitch often share habitat with Sacramento blackfish, Sacramento suckers, and Sacramento pikeminnows. In altered systems hitch are found among introduced species like mosquitofish, catfish, and centrarchids. In a stream the hitch may use its upturned mouth to feed in the water column or to feed on the surface for insects. In a lake hitch may occupy different spaces depending upon age. Juveniles typically live in shallow vegetated areas near shore, while the older fish (>80 days) live in deeper offshore waters. Young hitch may shoal for the first two months of residency in a lake. The diet of a limnetic (lake-dwelling) hitch may include zooplankton, crustaceans, or various forms of insects. Growth rates of hitch vary depending upon the environmental conditions, though in general females reach sexual maturity in 2-3 years, while males may reach sexual maturity in years 1-3. Spawning typically happens in the tributaries to lakes and rivers, and may begin as early as February and end as late as July. Fecundity in hitch is relatively high as one female may produce 3,000 to 63,000 eggs, depending upon body size. When spawning adults reach a suitable riffle for breeding one female may be surrounded by 1-5 males. A ripe female releases her eggs into the current and the males immediately fertilize the eggs. The eggs then settle into the gravel substrate where the size of the ova will increase and help lodge it into the rock particles. In 3-7 days the embryos hatch, and 3-4 days after the hatch the embryos begin to swim freely. The young hitch may swim downstream to a lake or slough, or reside within the stream under the cover of aquatic plants. Hitch generally live for a total of 4-6 years.

 

Hitch jumping at Bell Hill Road Crossing on Adobe Creek (Clear Lake, CA) on 4/21/2006. Photo by Richard Macedo, California Department of Fish and Game.
Hitch jumping at Bell Hill Road Crossing on Adobe Creek (Clear Lake, CA) on 4/21/2006. Photo by Richard Macedo, California Department of Fish and Game.

Hitch spawning at Bell Hill Road Crossing on Adobe Creek (Clear Lake, CA) on 4/21/2006. Photo by Richard Macedo, California Department of Fish and Game.
Hitch spawning at Bell Hill Road Crossing on Adobe Creek (Clear Lake, CA) on 4/21/2006. Photo by Richard Macedo, California Department of Fish and Game.

 

Videos of Clear Lake hitch spawning:

<img src="//ucanr.edu/media/sb379596.png" alt="Image from Flash Video" />
Hitch (Clear Lake hitch) spawning in Kelsey Creek, a tributary of Clear Lake. Filmed 03/26/08 by Lisa Thompson. Thanks to Peter Windrem (Chi Council for the Clear Lake Hitch) for showing me the fish!

<img src="//ucanr.edu/media/sb379595.png" alt="Image from Flash Video" />
Hitch (Clear Lake hitch) spawning in Kelsey Creek, a tributary of Clear Lake. Single fish swimming along shore. Filmed 03/26/08 by Lisa Thompson. Thanks to Peter Windrem (Chi Council for the Clear Lake Hitch) for showing me the fish!

Links to Other Research

 

Clear Lake Annotated Bibliography

August 29, 2011

By Kristina L. Weber, Lisa C. Thompson, Gregory A. Giusti, and Ryan F. Keiffer

University of California Cooperative Extension

Wildlife, Fish, and Conservation Biology Department

UC Davis, 1 Shields Ave, Davis, CA 95616

Contact: lcthompson@ucdavis.edu

This bibliography contains 302 references, including journal articles, books, reports, newspaper articles, and videos. The main focus was on fish, particularly Clear Lake hitch and largemouth bass, but there are also references on culture, settlement, mining, and lake water chemistry.  Items are listed in alphabetical order by author, beginning with anonymous works (no author listed).

The bibliography is available for download as a pdf file:

Clear Lake Annotated Bibliography (pdf file)

and as an html link:

Clear Lake Annotated Bibliography (html file)

A version of this bibliography is also available in EndNote, at no cost. Please contact Lisa Thompson at lcthompson@ucdavis.edu to obtain a copy.

Watershed
  • Alisal-Elkhorn Sloughs Watershed
  • Carmel Watershed
  • Coyote Watershed
  • Honcut Headwaters Watershed
  • Lower American Watershed
  • Lower Bear Watershed
  • Lower Butte
  • Lower Cache Watershed
  • Lower Calaveras-Mormon Slough Watershed
  • Lower Cosumnes-Lower Mokelumne Watershed
  • Lower Feather Watershed
  • Lower Sacramento Watershed
  • Lower Yuba Watershed
  • Middle Fork Feather Watershed
  • Middle San Joaquin-Lower Chowchilla Watershed
  • Middle San Joaquin-Lower Merced-Lower Stanislaus Watershed
  • Mill Watershed
  • Pajaro Watershed
  • Russian Watershed
  • Sacramento-Lower Thomes Watershed
  • Sacramento-Stone Corral Watershed
  • Salinas Watershed
  • San Francisco Bay Watershed
  • San Joaquin Delta Watershed
  • San Pablo Bay Watershed
  • Suisun Bay Watershed
  • Tulare-Buena Vista Lakes Watershed
  • Upper Cache Watershed
  • Upper Calaveras Watershed
  • Upper Chowchilla-Upper Fresno Watershed
  • Upper Cosumnes Watershed
  • Upper Deer-Upper White Watershed
  • Upper Dry Watershed
  • Upper Kaweah Watershed
  • Upper King Watershed
  • Upper Merced Watershed
  • Upper Mokelumne Watershed
  • Upper Putah Watershed
  • Upper San Joaquin Watershed
  • Upper Stanislaus Watershed
  • Upper Stony Watershed
  • Upper Tule Watershed
  • Upper Tuolumne Watershed
  • Upper Yuba Watershed

Kern Brook Lamprey

Scientific Name
Lampetra hubbsi
Native
Native Species
Identification

missing fish photo

  • Small lamprey, adults: 8-14 cm TL, ammocoetes: 11-15 cm TL
  • Body segments (myomeres): 51-57, mean of 54
  • Coloration: Back and sides gray-brown, white underside
  • Dorsal fins absent of pigment, black pigmentation present on tail near notochord
  • Oral disc narrower than head
  • Plates or teeth:
    • Supraoral plate: 2 cusps
    • Lateral teeth: 3-4 teeth on each side, 1 cusp each
Life History

The non-predatory Kern brook lamprey has not been extensively studied and identified because of a limited and scattered distribution. They appear similar to the western brook lamprey in both appearance and life history. Kern brook lampreys tend to occupy slow backwaters of foothill streams. Ammocoetes burrow themselves into the soft silt or sandy substrate in the margins of runs or pools. Favorable conditions includes substrate depths of 30-110 cm and water temperatures that rarely exceed 25°C. Biologists presume that the Kern brook lamprey undergoes metamorphosis in fall and then spawns in gravelly substrate in the spring before dying.

Links to Other Research
Watershed
  • Middle San Joaquin-Lower Chowchilla Watershed
  • Middle San Joaquin-Lower Merced-Lower Stanislaus Watershed
  • Mill Watershed
  • Tulare-Buena Vista Lakes Watershed
  • Upper Dry Watershed
  • Upper Kaweah Watershed
  • Upper King Watershed
  • Upper Merced Watershed

Klamath Largescale Sucker

Scientific Name
Catostomus snyderi
Native
Native Species
Identification

missing fish photo

  • Fairly large sucker, may reach lengths up to 46 cm FL
  • Short head, thick caudal peduncle, solid body
  • Short dorsal fin, insertion closer to tip of snout than tail
  • Subterminal mouth
  • Narrow upper lip: 4-5 rows of papillae
  • Deep medial notch in lower lip, one complete row of papillae
  • Green back, yellow to gold underside
  • Fin rays: dorsal 11 (10-12), anal 7
  • Lateral line scales: 67-81, 11-14 scales above line, 8-12 scales below line

 

Life History

 

Klamath largescale suckers have not been extensively studied. Today they are found primarily in large streams where water quality is fairly high, though they may also be found in lakes Historically they were probably more abundant in lakes, especially those with deep water. Klamath largescale suckers have shown an ability to make significant journeys that may include using fish ladders. Klamath largescale suckers can survive short stints in water temperatures that exceed 32°C and where dissolved oxygen levels are around 1 mg/L. Like other suckers, Klamath largescale suckers are believed to be benthic omnivores. Juveniles have been found to feed on primarily zooplankton in Upper Klamath Lake. Most suckers reach sexual maturity in 4-6 years at a length of 20-30 cm FL. The oldest recorded Klamath largescale sucker was 31 years old and measured 46 cm FL. Spawning occurs in upstream tributaries with migration happening between March and May. Males probably arrive at spawning grounds before females. Females are estimated to produce an approximate range of 39,000 to 64,000 eggs.

Links to Other Research
Watershed
  • Lost Watershed
  • Upper Klamath Watershed

Klamath River Lamprey

Scientific Name
Lampetra similis
Native
Native Species
Identification

Klamath River lamprey. Captured attached to a brown trout from the upper Trinity River near river mile 85 on 22 July 2009. Total length: 27 cm. Photo courtesy of John Hileman, California Department of Fish and Game.
Klamath River lamprey. Captured attached to a brown trout from the upper Trinity River near river mile 85 on 22 July 2009. Total length: 27 cm. Photo courtesy of John Hileman, California Department of Fish and Game.

Klamath River lamprey, mouth. Captured attached to a brown trout from the upper Trinity River near river mile 85 on 22 July 2009. Photo courtesy of John Hileman, California Department of Fish and Game.
Klamath River lamprey, mouth. Captured attached to a brown trout from the upper Trinity River near river mile 85 on 22 July 2009. Photo courtesy of John Hileman, California Department of Fish and Game.

Klamath River lamprey, trunk myomeres. Blue arrows indicate section along which 63 trunk myomeres were counted. Photo courtesy of John Hileman, California Department of Fish and Game. Edited by Lisa Thompson, UC Davis.
Klamath River lamprey, trunk myomeres. Blue arrows indicate section along which 63 trunk myomeres were counted. Photo courtesy of John Hileman, California Department of Fish and Game. Edited by Lisa Thompson, UC Davis.

Brown trout with lamprey scar. Captured from the Trinity River on 29 July 2009. Photo courtesy of John Hileman, California Department of Fish and Game.
Brown trout with lamprey scar. Captured from the Trinity River on 29 July 2009. Photo courtesy of John Hileman, California Department of Fish and Game.

  • Small lamprey: 14-27 cm TL
  • Two dorsal fins
  • Body segments (myomeres): 58-65
  • Body coloration: dark body and lower oral hood, may have ridge of light pigmentation near tail
  • Oral disc length about 9% of TL, wider than head
  • Most prominent teeth of California lampreys
  • Supraoral lamina: 3 cusps
  • Transverse lingual lamina (tongue plate): 20-29 cusps
  • Four inner lateral plates on both sides: (bicuspid-tricuspid-tricuspid-bicuspid)
  • Anterior field above mouth:13 teeth
  • Posterior field below mouth:18 teeth
Life History

Klamath River lampreys have not been fully studied and documented. Fish biologists know that they occupy the Klamath River and nearby reservoirs and lakes, where they live a predatory lifestyle. Klamath River lampreys have been observed in the Upper Klamath River and Upper Klamath Lake, as well as the lower Klamath and Trinity Rivers and tributaries.

Links to Other Research
Watershed
  • Lost Watershed
  • Lower Klamath Watershed
  • South Fork Trinity Watershed
  • Trinity Watershed
  • Upper Klamath Watershed

Klamath Smallscale Sucker

Scientific Name
Catostomus rimiculus
Native
Native Species
Identification

Klamath smallscale sucker, captured from the maintstem Klamath River near Orleans, CA. Photo by Brian Hodge, Humboldt State University.
Klamath smallscale sucker, captured from the maintstem Klamath River near Orleans, CA. Photo by Brian Hodge, Humboldt State University.

Klamath smallscale sucker (mouth), captured from the maintstem Klamath River near Orleans, CA. Photo by Brian Hodge, Humboldt State University.
Klamath smallscale sucker (mouth), captured from the maintstem Klamath River near Orleans, CA. Photo by Brian Hodge, Humboldt State University.

  • Adults may reach 35 cm SL, rarely exceed 50 cm FL
  • Subterminal “sucker” mouth
  • Small eyes, large lips with papillae, cleft in lower lip
  • Olive brown back and sides, yellow to white underside
  • Fin rays: dorsal 10-12, anal, 6-7, pectoral 16-18
  • Lateral line scales: 81-93
Life History

The Klamath smallscale sucker appears to have a life history similar to other species such as the Sacramento and mountain suckers. Smallscale suckers are found primarily in deep slow pools of major rivers, though they may also occupy slow stretches of tributary streams and reservoirs. The Klamath smallscale suckers have been observed feeding in schools along stream bottoms and are often found in association with speckled dace, sculpins, and juvenile steelhead. Spawning by this species occurs in springtime, and adults move into tributary streams to breed. Females may lay 15,000 to 20,000 eggs which are then fertilized by the males. Juvenile suckers spend the first part of their life in small tributary streams before moving into larger water bodies. The Klamath smallscale sucker may live up to 15 years.

Links to Other Research
Watershed
  • Lower Klamath Watershed
  • Salmon Watershed
  • Scott Watershed
  • Shasta Watershed
  • Smith Watershed
  • South Fork Trinity Watershed
  • Trinity Watershed
  • Upper Klamath Watershed

Kokanee (Sockeye Salmon)

Scientific Name
Oncorhynchus nerka
Native
Non-Native
Identification

Kokanee with sizes indicated (Canadian dollar used for reference) Location: Kootenay Lake, BC, Canada, Date: circa 1994, Photo by Lisa Thompson
Kokanee with sizes indicated (Canadian dollar used for reference) Location: Kootenay Lake, BC, Canada, Date: circa 1994, Photo by Lisa Thompson

Kokanee spawning in the Meadow Creek Spawning Channel, Kootenay Lake, BC, Canada, Date: circa 1994, Photo by Lisa Thompson
Kokanee spawning in the Meadow Creek Spawning Channel, Kootenay Lake, BC, Canada, Date: circa 1994, Photo by Lisa Thompson

  • Blue-green back with silvery sides when non-spawning
  • Solid, bright red body with green head when spawning
  • Spawning males also develop a distinct hump on their back and long and hooked snout
  • Slightly oblique mouth
  • 11-26 dorsal, 13-18 anal, 11-21 pectoral, and 9-11 pelvic rays
  • 120-150 scales along the lateral line
  • Parr have 8-14 oval parr marks, narrower than the spaces between them, centered on the lateral line
Life History

 

Kokanee is technically a sub-species of the sockeye salmon but its landlocked behavior and development makes it enough of a unique organism to be treated independently. Kokanee are most common in well oxygenated, open waters with temperatures in the range of 10-15°C, normally large lakes and reservoirs. Their diet consists mainly of zooplankton, including copepods and cladocerans, with a preference for a form of cladoceran called Daphnia (water fleas). Small fish and insects are occasionally taken as well. Their diet can change throughout the year and during an individual’s lifetime but this is based upon food availability and not a preference change.

The size and age of maturity varies based on environmental factors like food availability, light, and temperature, but also on the population origin of the individual. Depending on where the introduced kokanee came from, life cycles can be as short as 2 years or as long as 7, but most mature in 4 years, including the Lake Tahoe population. This will usually place adults at around 20 cm in length. Spawning begins in August and usually runs into early February but kokanee have been found spawning as late as April. Again genetic factors and environmental factors like temperature both play a role in this timing. Regardless of stock, when kokanee are ready to spawn they congregate near the mouths of streams or near lake spawning sites where they were spawned or planted using the smell of the river to home in. Females build redds out of the gravel substrate and both sexes will work to defend the nesting area. The female will then lay as many eggs as she can into the nest followed by at least one male who will then fertilize them. Once fertilized, the eggs are buried by the female beneath 5-15 cm of gravel. Fecundites vary between 200 and 1,800 eggs per female, depending on her size, and it is not uncommon for the female to die before she can release all of her eggs. Most kokanee die 2-4 days after spawning. Depending on when the spawning occurred, fry emerge in April through June and move downstream to mature in lakes. They will reach 10-25 cm TL their first year and 23-47 cm TL in their fourth. The Lake Tahoe population formerly averaged close to the upper edge of these numbers but the introduction of opossum shrimp (Mysis relicta), which competes with kokanee for zooplankton, has reduced food availability and brought kokanee growth rates down.

Links to Other Research
Watershed

Lahontan Redside

Scientific Name
Richardsonius egregius
Native
Native Species
Identification

Lahontan redside, caught in Bogard Spring Creek (Eagle Lake watershed) in 2011. Photo by Teejay O'Rear. Scale in cm.
Lahontan redside, caught in Bogard Spring Creek (Eagle Lake watershed) in 2011. Photo by Teejay O'Rear. Scale in cm.

Lahontan redside. Photo courtesy of Professor Peter B. Moyle.
Lahontan redside. Photo courtesy of Professor Peter B. Moyle.

  • Small, skinny minnow (TL 4 x body depth), max. length 16 cm TL
  • Large eyes, deeply forked tail, terminal mouth (maxilla only reaches front end of eye)
  • Breeding adults: red or scarlet lateral band amidst yellow, olivaceous back, silver underside, breeding tubercles present
  • Males: tubercles larger and more numerous, present on pectoral fins, darker colorations, pectoral fins reach pelvic origin when depressed
  • Non-breeding adults: red-stripe reduced or absent, lateral band still visible
  • Fin Rays: dorsal 7-8, anal 8-20
  • Lateral Line Scales: 52-63
Life History

Lahontan resides are native to both lakes and streams on the eastern side of the Sierra Nevada mountain range, although they have been introduced to the upper reaches of some watersheds on the western side of the range. River and stream inhabitants tend to occupy different niches within the waterway depending upon size. Adults hold in the top of pools near salmonids while the juvenile fish stick closer to the stream margins. The diet of stream residents may include drifting insects as well as benthic insects and algae. They tend to feed at night in order to avoid predators such as birds. Lahontan redsides may have important interactions with other species such as Tahoe suckers and brown trout. Sucker populations may suffer when their eggs provide food and nutrients for the Lahontan redsides, whereas the brown trout can prey heavily upon the redside and limit their populations. Lahontan redsides living in lakes tend to shoal and forage by swimming in the littoral zone. A diet study in Lake Tahoe found that these fish feed on both benthic and surface organisms, though primary food targets may vary highly throughout the day. In Eagle Lake the primary constituents of the Lahontan redside diet include caddisfly larvae, planktonic cladocerans, and amphipods. Lahontan redsides reach sexual maturity in the summer of year 3-4, and their growth rates are similar everywhere though fish in colder waters tend to grow slightly slower. Spawning occurs between late May and August with a peak at the end of June. During this time lake-dwelling Lahontan redsides often move up into tributary streams to breed. Spawning takes place over gravel in riffles or pool tails. Females in Lake Tahoe produce and average of 1,125 eggs. Groups of 20-100 fish swim over the spawning gravels and release their eggs and milt. The fertilized eggs become lodged in the substrate where they will incubate and later hatch. The newly hatched young swim down to slow water at the mouth of the spawning stream and hide in shoals under cover. The Lahontan redside has a maximum lifespan of around 5 years.

Links to Other Research
Watershed
  • East Branch North Fork Feather Watershed
  • East Walker Watershed
  • Honey-Eagle Lakes Watershed
  • Lake Tahoe Watershed
  • Middle Fork Feather Watershed
  • Mono Lake Watershed
  • North Fork American Watershed
  • North Fork Feather Watershed
  • Truckee Watershed
  • Upper Carson Watershed
  • Upper Mokelumne Watershed
  • West Walker Watershed

Lake Trout

Scientific Name
Salvelinus namaycush
Native
Non-Native
Identification

Lake trout, captured from Donner Lake on 12/21/2009. Length: 53 cm (21
Lake trout, captured from Donner Lake on 12/21/2009. Length: 53 cm (21") TL. Photo by Teejay O'Rear.

Lake trout. Caught at Caples Lake, California. Date: August 2008. Photo by Dan Worth, California Department of Fish and Game.
Lake trout. Caught at Caples Lake, California. Date: August 2008. Photo by Dan Worth, California Department of Fish and Game.

Lake trout caught in Seneca Lake, New York in October 2008. Photo by Arthur Masloski.
Lake trout caught in Seneca Lake, New York in October 2008. Photo by Arthur Masloski.

  • Heavy bodied with broad head taking up nearly a quarter of the length of the body
  • Large mouth with maxillae extending past the posterior margin of the eye and well developed teeth present on both jaws
  • Deeply forked tail with pointed lobes
  • Light green to gray over entire body with irregular white to yellow spots and a pale white border on the leading edge of the pectoral fins, pelvic fins, and anal fin
  • Parr have 7-12 irregular parr marks and small irregular white spots on their back
  • 8-10 dorsal, 8-10 anal, 8-11 pelvic, and 12-17 pectoral fin rays
  • 116-138 small scales on the lateral line
Life History

As their name would suggest, lake trout are most common in deep, cold water lakes but are also occasionally found in streams and other shallow waters. They will generally keep to the deeper water, usually just over 30 m but sometimes as deep as 430 m, except in spring and fall when they move towards shallower waters in order to feed. Regardless of depth they will always stay close to the bottom and will sometimes congregate around deep reefs. They are heavily dependent on cold water temperatures, preferring water below 13°C and dying in waters above 23°C. Their salinity tolerance is usually close to 11-13 ppt. Lake trout diet is dependent on size, with trout becoming more piscivorous as they get larger. In Lake Tahoe lake trout under 13 cm in length have traditionally fed on zooplankton but with the recent introduction of the opossum shrimp (Mysis relicta) the Daphnia zooplankton population in the lake has decreased, forcing small trout to prey on the Mysis instead. Individuals greater than 13 cm in length still feed heavily on zooplankton but begin to feed on small benthic fish species like the Paiute sculpin. By the time lake trout reach 50 cm in length fish like the Tahoe sucker have become the most common prey items.

Lake trout will reach maturity sometime between their fifth and eleventh year and will spawn every year after. Mating occurs between mid-September and mid-November in areas with rubble and boulder bottoms deeper than 37 m. Males arrive first to clean rocks and macrophytes of silt and debris with their fins and body. Spawning takes place at night with a brief courtship ceremony where a single female will mate with multiple males. Unlike most trout species, the fertilized eggs of lake trout fall between cracks in the rocks rather than a constructed redd. An average of 3,400 eggs per female was measured in Lake Tahoe. Embryos hatch in the rocks 4-6 months later. The young will stay here for a month or so after hatching and are believed to stay on the bottom feeding on invertebrates and zooplankton for the next 1 to 2 years. During that first year they will grow to 12 cm and add 5-7 cm per year over the next 10 years. In Lake Tahoe they can live to be 17 years old and individuals as old as 41 have been found elsewhere. Individuals have been found in Lake Tahoe measuring longer than 1 m and weighing more than 9.1 kg.

Links to Other Research
Watershed

Land Shark

Scientific Name
Chevus chasus
Native
Non-Native
Identification

Land shark (and incapacitated victim). South Fork American River, near Placerville, CA. October 22, 2011. Photo by Dave Giordano.
Land shark (and incapacitated victim). South Fork American River, near Placerville, CA. October 22, 2011. Photo by Dave Giordano.

  • Large body size – up to 6 feet (2 m) SL
  • Gray body color
  • Heterocercal tail
  • Small beady eyes
  • Row of large, pointed white teeth on top and bottom of mouth
  • May be accompanied by suspenseful, pulsing, threatening music
Life History

This fictional fish was first identified in 1975, with several other sightings in the late 1970s and early 1980s, and one report from 2001.  The land shark is native to the eastern United States, and is most often observed late on Saturday nights in New York City, although it occasionally makes appearances in Los Angeles, California. More rarely, it appears in television newsrooms or on airplanes. In October 2011 there was a rare sighting of a land shark along the South Fork American River, near Placerville, California.

The land shark usually inhabits urban areas, where it preys mainly upon young women, although it has also been known to attack bespectacled marine biologists and crusty sea captains. This is a very clever fish that is capable of disguising its voice and ringing doorbells.  It may pretend to be a plumber or a dolphin, or to be delivering a telegram, candygram, or flowers. It has been known to strike on Hallowe’en, impersonating a trick-or-treater and purporting to be collecting money for charity.

It is not clear how this shark reproduces, since it has a habit of eating its potential mates.

Links to Other Research

We continue to be on the lookout for land sharks during our fieldwork for other projects.  Please report any sightings to the webmaster. If a land shark is sighted, members of the public should exercise caution in approaching the fish.  As the photo above shows, even a highly trained wizard may be no match for a land shark.

Watershed

Largemouth Bass

Scientific Name
Micropterus salmoides
Native
Non-Native
Identification

Largemouth bass approximately 30 cm (12”) long. Location: Deer Creek, California Date 6/22/2007.
Largemouth bass approximately 30 cm (12”) long. Location: Deer Creek, California Date 6/22/2007.

Largemouth bass, captured from Snodgrass Slough, CA, and released. Length = 22.75
Largemouth bass, captured from Snodgrass Slough, CA, and released. Length = 22.75" (57.8 cm). Weight (est.) = 9.2 lb (4.17 kg). Photo by Gary Riddle.

Largemouth bass (showing maxilla) caught in Lake Berryessa Reservoir in March 2009 by Teejay O'Rear. Photo by Amber Manfree.
Largemouth bass (showing maxilla) caught in Lake Berryessa Reservoir in March 2009 by Teejay O'Rear. Photo by Amber Manfree.

Largemouth bass, approximately 17.5 cm (7”) long. Location: Deer Creek, California Date: 6/20/2007. Note: maxilla is less pronounced in juveniles than in adults.
Largemouth bass, approximately 17.5 cm (7”) long. Location: Deer Creek, California Date: 6/20/2007. Note: maxilla is less pronounced in juveniles than in adults.

Largemouth bass, approximately 11 cm (4.5”) long. Location: Deer Creek, CA. Date: 6/20/2007. Note: maxilla is less pronounced in juveniles than in adults.
Largemouth bass, approximately 11 cm (4.5”) long. Location: Deer Creek, CA. Date: 6/20/2007. Note: maxilla is less pronounced in juveniles than in adults.

Largemouth bass, approximately 11 cm (4.5”) long. Location: Deer Creek, CA. Date: 6/20/2007.
Largemouth bass, approximately 11 cm (4.5”) long. Location: Deer Creek, CA. Date: 6/20/2007.

Juvenile basses. Photos courtesy of Patrick Crain and Scott Matern.
Juvenile basses. Photos courtesy of Patrick Crain and Scott Matern.

  • Heavy but elongate body with a large mouth
  • 2 dorsal fin portions are nearly separate
  • Black lateral stripe
  • 12-14 dorsal, 11-12 anal, and 13-17 pectoral fin rays
  • 9 dorsal and 3 anal spines
  • 58-72 scales on the lateral line
  • Scales absent from the base of dorsal and anal fin
  • Olive gray to shiny green back and sides, white on the belly, with a stripe separating the two colors
  • Brown eyes
Life History

 

Largemouth Bass are most common in warm shallow waters with moderate clarity and beds of aquatic plants. This includes farm ponds, lakes, reservoirs, sloughs, and river backwaters. They may be pushed out of streams by high flows but will survive in flooded areas and recolonize when the flows drop again. Lake populations stay close to shore in water 1-3 m deep. Largemouth bass can survive temperatures up to 36-37°C but 27°C is generally preferred. They can also survive in water with dissolved oxygen levels as low as 1 mg/L but will avoid areas with salinities higher than 3 ppt and are intolerant of high alkalinity levels. Juveniles and populations in crowded lakes may school but the majority are solitary hunters that stalk around a piece of submerged debris or roam widely in open water. Foraging happens throughout the daylight hours but is most intense at dusk before becoming almost completely nonexistent at night. Pursuit and ambush strategies are both used to catch prey and a largemouth bass’s behavioral preference will change with availability of prey and the habitat. This changing of behavior will often lead to a largemouth bass specializing in a single type of prey at least for a short period of time, but switching this focus numerous times throughout the individual’s lifetime. In general, fry feed on crustaceans and rotifers before taking on insects and fish fry at 50-60 mm in length, and becoming primarily piscivorous at 100-125 mm in length. Crayfish, tadpoles, or frogs may also be preferred once a largemouth bass has grown large enough to digest them.

Maturity is reached when males have grown to 18-21 cm in length and females have grown to 20-25 cm in length. Spawning starts in March or April when temperatures reach 15-16°C and continues through June in temperatures up to 24°C. Males build nests by brushing out shallow depressions, up to 1 m in diameter, into sand, gravel, or debris-littered bottoms. This is usually in areas 0.5-2 m deep and commonly next to submerged objects. These nests may be built close together but they are not colonial, and males will defend their nest as vigorously against other males as they would predators. Spawning is initiated by a female repeatedly swimming by a nest, changing colors, and keeping her head down in a mating posture. Eventually the pair circle the nest with the male nipping at the female and the female occasionally rubbing her abdomen on the nest floor. The pair will then settle into the nest and release their eggs and milt simultaneously. Each female may lay 2,000-94,000 eggs per season as she visits multiple males in the area. These eggs adhere to the nest and hatch 2-7 days later. The offspring stay in the nest for 5-8 days before they become free swimming, and will remain guarded by the male for another 2-4 weeks. At this point they are left to school on their own near shore. Growth is highly variable depending on genetics, food availability, competition, temperature, and other conditions. This diversity of constraints results in fish growing to anywhere between 5 cm and 20 cm in their first year, and 20 cm to 41 cm in their fourth. The largest individual recorded measured 76 cm and weighed 10.5 kg, and the oldest individual was 16 years old.

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Watershed

Longfin Smelt

Scientific Name
Spirinchus thaleichthys
Native
Native Species
Identification

Longfin smelt, male, 141 mm FL. Photographed on March 7, 2008 at the Tracy Fish Collection Facility, Tracy, CA. Photo by René Reyes, US Bureau of Reclamation.
Longfin smelt, male, 141 mm FL. Photographed on March 7, 2008 at the Tracy Fish Collection Facility, Tracy, CA. Photo by René Reyes, US Bureau of Reclamation.

Longfin smelt, 110 mm FL. Photographed on February 14, 2008 at the Tracy Fish Collection Facility, Tracy, CA. Photo by René Reyes, US Bureau of Reclamation.
Longfin smelt, 110 mm FL. Photographed on February 14, 2008 at the Tracy Fish Collection Facility, Tracy, CA. Photo by René Reyes, US Bureau of Reclamation.

Longfin smelt, ventral view, 150 mm FL. Photographed on February 22, 2008 at the Tracy Fish Collection Facility, Tracy, CA. Photo by René Reyes, US Bureau of Reclamation.
Longfin smelt, ventral view, 150 mm FL. Photographed on February 22, 2008 at the Tracy Fish Collection Facility, Tracy, CA. Photo by René Reyes, US Bureau of Reclamation.

  • Small silvery fish, adipose fin present, adults reach 12-15 cm SL
  • Long pectoral fin may reach pelvic fin origin, long maxillary bone may reach past eye
  • Striations on operculum weak or absent, lower jaw protrudes
  • Teeth present on tongue, vomer, palatines, and both jaws
  • Olive to pink iridescent backs, silvery sides
  • Mature males: usually darker than mature females, dilated lateral line, large stiff dorsal and anal fins, breeding tubercles on scales and paired fins
  • Fin rays: dorsal 8-10, anal 15-22, pectoral 10-12
  • Lateral line scales: (incomplete) 54-65
Life History

 

Longfin smelt in California are primarily an anadromous estuarine species that can tolerate salinities ranging from freshwater to nearly pure seawater. Most longfin smelt occupy the middle or bottom of a water column and tend to favor temperatures in the range of 16-18°C and salinities ranging from 15-30 ppt. Their spatial distribution within a bay or estuary is seasonally variable. Generally speaking longfin smelt are found closer to the ocean during summer whereas they move upstream in cool seasons. They can survive summer temperatures up to 20°C. Longfin smelt may also make daily migrations; remaining deep during the day and rising to the surface at night. Avoiding surface waters at night helps these fish avoid predation from birds, marine mammals, and other fish. In addition longfin smelt may follow food sources which include opossum shrimp, copepods, and crustaceans. Longfin smelt reach 6-7 cm SL in the first 9-10 months of life. Growth is minimal during their first winter, but the growth rate increases again in their second summer and fall when they may reach 9-11 cm SL. The largest longfin smelt are female fish that reach standard lengths up to 15 cm in their third year. Longfin smelt move into freshwater to spawn, with the peak breeding season occurring between February and April. Older and larger fish tend to spawn in the later stages of the spawning season. Males are first to move into areas with gravel or sandy substrate where rocks and aquatic plants are present. Spawning occurs at night, when female smelt release an average of 5,000-24,000 adhesive eggs. Smelt typically die after spawning though a few females may survive another year. The eggs hatch in around 40 days and the larvae are washed downstream into the estuary. In the San Francisco estuary high stream flows seem to lead to higher resulting populations of smelt. Larvae are mobile and move according to salinity preferences. In 30-60 days the larvae morph into juvenile fish.

Links to Other Research
Watershed
  • Coyote Watershed
  • Lower Eel Watershed
  • Lower Klamath Watershed
  • Lower Sacramento Watershed
  • Mad-Redwood Watershed
  • Russian Watershed
  • San Francisco Bay Watershed
  • San Joaquin Delta Watershed
  • San Pablo Bay Watershed
  • Suisun Bay Watershed

Longjaw Mudsucker

Scientific Name
Gillichthys mirabilis
Native
Native Species
Identification

Longjaw mudsucker. Location: Eureka Slough, Humboldt Bay, CA. Date: 2003. Photo by Mike Wallace, California Department of Fish and Game.
Longjaw mudsucker. Location: Eureka Slough, Humboldt Bay, CA. Date: 2003. Photo by Mike Wallace, California Department of Fish and Game.

  • Goby
  • Elongated body
  • Max. 150 mm TL, regularly 135-140 mm SL
  • Pelvic fins united to form suction cup, 2 dorsal fins,heavy bodied goby
  • Terminal mouth, upper jaw nearly reaches opercular opening (jaw reaches rear margin of eye in juveniles)
  • Blunt head, small widely-set eyes (eyes more lateral in juveniles)
  • Small scales: absent on front of belly, large on caudal peduncle
  • Coloration: Dark brown to olive back and sides,yellow bellies, often have faint vertical bars on sides
  • Juveniles: 8 vertical bars on sides, dark blotch on posterior side of 1st dorsal fin
  • Fin spines/rays: 1st dorsal 4-8 spines, 2nd dorsal 10-17 elements, anal 9-17 elements, pectoral 15-23 rays
  • Lateral line scales: 60-100
Life History

Longjaw mudsuckers primarily inhabit shallow sloughs and tidal mudflats in the upper ends of bays and estuaries. They are occasionally found in freshwater but cannot survive more than 3-7 days at such a low salinity level. They can sustain populations in water with salinities ranging from 12 ppt to 82.5 ppt, and in water with a temperature as high as 35°C. As the tide goes out longjaw mudsucker survive by burrowing in mud and gulping air. They also have the ability to move short distances across land to reach water. In northern California longjaw mudsuckers are commonly found in association with topsmelt, yellowfin goby, staghorn sculpin, rainwater killifish, and threespine stickleback. In southern California mudsuckers are commonly found around California killifish, arrow goby, and topsmelt. Their diet changes with the availability of prey. Adult inhabitants of the Salton Sea eat mostly pile worms, while coastal dwellers feed mostly on benthic prey such as algae, isopods, amphipods, and small fish. Longjaw mudsuckers live approximately 2 years and may reach sexual maturity and a length of 60-80 mm in several months. Growth is rapid during summer and slows during winter. Breeding typically occurs from January through July in the southern distribution and in December-June in the San Francisco Bay. Male mudsuckers create and defend breeding burrows. Females produce 8,000 to 27,000 eggs and spawn multiple times in a season. Fertilized eggs are attached to the walls of burrows and male fish defend the burrows for 10-12 days till the embryos hatch. Newly emerged larvae are pelagic and settle to the bottom as juveniles when they reach a total length of 8-12 mm.

Links to Other Research
Watershed
  • Aliso-San Onofre Watershed
  • Calleguas Watershed
  • Carmel Watershed
  • Central Coastal Watershed
  • Cottonwood Tijuana Watershed
  • Coyote Watershed
  • Los Angeles Watershed
  • Newport Bay Watershed
  • Pajaro Watershed
  • Salton Sea Watershed
  • San Antonio Watershed
  • San Diego Watershed
  • San Francisco Bay Watershed
  • San Francisco Coastal South Watershed
  • San Gabriel Watershed
  • San Lorenzo-Soquel Watershed
  • San Luis Rey-Escondido Watershed
  • San Pablo Bay Watershed
  • Santa Ana Watershed
  • Santa Barbara Coastal Watershed
  • Santa Margarita Watershed
  • Santa Maria Watershed
  • Santa Monica Bay Watershed
  • Seal Beach Watershed
  • Suisun Bay Watershed
  • Tomales-Drake Bays Watershed
  • Ventura Watershed

Lost River Sucker

Scientific Name
Deltistes luxatus
Native
Native Species
Identification

missing fish photo

  • Large sucker, up to 1 m TL (4.5kg)
  • Long narrow head, small eyes, small sub-terminal mouth (almost terminal)
  • Fleshy lips, upper lip: 2-5 rows of large papillae, lower lip: medial division, 1-3 rows of papillae
  • Dorsal fin origin slightly anterior of pelvic origin
  • Coloration: brown to black back, brassy sides, white to yellow ventrally
  • Fin rays: dorsal 10-12, pelvic 10, anal 7-8
  • Lateral line scales: 82-113 (13-16 scales above line, 8-12 scales below line)

 

Life History

 

Lost River suckers favor shallow lakes with clear, cool (16-24°C), well-oxygenated water. Such environmental conditions promote the growth of healthy aquatic vegetation and marshland, which provide food and cover for Lost River suckers. Though favorable, these conditions are limited, and in some lakes Lost River suckers are only found at the mouth of inflowing rivers. Suckers begin dying when dissolved oxygen levels drop below 1.58 mg/L, the pH exceeds 10, and when water temperatures exceed 31-32°C. Mortality rates are even higher when these conditions become more extreme. In Clear Lake (Modoc County) the Lost River suckers remain in deep water through winter and disperse throughout the lake in summer months. Like other suckers, Lost River suckers feed primarily on detritus by grazing the bottom of a lake. Other food items include chironomid midge larvae, amphipods and zooplankton. Historically zooplankton and invertebrates may have made up a greater relative percentage of the sucker diet. During the period of life before the onset of maturity, suckers grow rapidly, reaching 35-50 cm FL in 5 or 6 years. They begin spawning after 5-9 years, making a short migration into a large tributary stream to breed. The suckers enter a stream in early February through April when rivers are swollen with winter and spring runoff. Spawning grounds are usually found in gravelly or rocky riffles and runs. One female is surrounded by several males in the swiftwater. As she releases some 102,000 to 236,000 eggs the males simultaneously fertilize the eggs. Fertilized eggs fall into the substrate and become lodged in the interstices to incubate. When larvae emerge they almost immediately move downstream towards lakes, though the trip may take up to 6 weeks. In lakes the young suckers gather in shallow shorelines where water quality is high and aquatic vegetation is present. As the suckers grow they progressively spend more time on the lake floor. Lost River suckers may reach 20-30 years old, though they historically lived over 40 years. Female suckers typically reach greater lengths than male suckers.

Links to Other Research
Watershed
  • Lost Watershed
  • Upper Klamath Watershed

Marbled Sculpin

Scientific Name
Cottus klamathensis
Native
Native Species
Identification

Marbled sculpin, approximately 7.5 cm (3”) long, taken by Lisa Thompson and Daniel J. Drake (dorsal view). Location: Shasta River, California. Date: 12/16/2003.
Marbled sculpin, approximately 7.5 cm (3”) long, taken by Lisa Thompson and Daniel J. Drake (dorsal view). Location: Shasta River, California. Date: 12/16/2003.

Marbled sculpin, approximately 7.5 cm (3”) long, taken by Lisa Thompson and Daniel J. Drake (ventral view). Location: Shasta River, California. Date: 12/16/2003
Marbled sculpin, approximately 7.5 cm (3”) long, taken by Lisa Thompson and Daniel J. Drake (ventral view). Location: Shasta River, California. Date: 12/16/2003

  • Small fish, over 80 mm SL unusual, 111 mm SL max
  • Large wide head, widely separated eyes, flattened snout, maxillary bone doesn’t extend past rear of eye
  • Smooth skin, 1 pre-opercular spine: may have 1-2 nodes below spine, 2 chin pores
  • Prickling may be well developed in young, absent or limited to behind pectoral fins in adult
  • Pectoral fins often checkered, body may appear “marbled”
  • Dorsal fins (2) broadly joined, lack dark patch on first dorsal
  • Fin rays/spines: 1st dorsal 7-8 spines, 2nd dorsal 18-22 rays, anal 13-15 rays, pectoral 14-16 rays, caudal 11-12
  • Lateral line incomplete: 15-28 pores
Life History

 

Marbled sculpin are usually found in cold (<20°C) spring-fed streams that have a low gradient and adequate aquatic vegetation. They tend to occupy pools or runs with cover, where optimal temperatures might be 11-15°C. Temperatures above 15°C are considered stressful, while sustained temperatures at 25-27°C are considered lethal. In some isolated streams marbled sculpin are found to have greater temperature tolerances and may be found inhabiting riffles or shallow water. Marbled sculpin develop primarily from spring through fall each year with the largest annual growth occurring in the first year of life. After 2 years the sculpin are able to reproduce and spawning occurs from late February through March. Each female only produces 139-650 large eggs which are placed in nests under the protection of rocks. The males guard the nests which may contain eggs from multiple females. When the larvae hatch they are 6-8 mm long and fully capable of swimming. However, young sculpin tend to minimize vulnerability by staying close to the nest site. Marbled sculpin typically live up to 5 years.

Links to Other Research
Watershed
  • Butte Watershed
  • Lost Watershed
  • Lower Klamath Watershed
  • Lower Pit Watershed
  • Salmon Watershed
  • Scott Watershed
  • Shasta Watershed
  • South Fork Trinity Watershed
  • Trinity Watershed
  • Upper Klamath Watershed

Mississippi Silverside

Scientific Name
Menidia beryllina
Native
Non-Native
Identification

Mississippi silverside approximately 8 cm (3”) long. Location: Suisun Marsh, California Date: 8/8/2008
Mississippi silverside approximately 8 cm (3”) long. Location: Suisun Marsh, California Date: 8/8/2008

Mississippi silverside approximately 9 cm (3.5”) long. Location: Suisun Marsh, California Date: 8/6/2007
Mississippi silverside approximately 9 cm (3.5”) long. Location: Suisun Marsh, California Date: 8/6/2007

Mississippi silverside, captured in rotary screw trap on Sacramento River at Knight's Landing. Photo by Dan Worth, California Department of Fish and Game.
Mississippi silverside, captured in rotary screw trap on Sacramento River at Knight's Landing. Photo by Dan Worth, California Department of Fish and Game.

  • Elongate and slender bodies with large eyes, oblique mouths and pointed heads flattened on top
  • Yellowish on the back with a silvery band on each side and translucent green underside
  • Pigment spots outline the upper row of scales and form two rows on the caudal peduncle between the anal and caudal fins
  • Two dorsal fins widely separated with 4-5 weak spines in the first and 1 spine and 8-9 rays in the second
  • Sickle shaped anal fin with 1 spine and 16-18 rays
  • 36-44 scales on the lateral line
Life History

 

Mississippi silversides are most common in shallow, warmwater lakes, reservoirs, and estuaries. They school here in very large numbers, concentrated near protected areas with sand or gravel bottoms. Temperatures between 20°C and 25°C are preferred but Mississippi silversides have been found in waters as cold as 8°C and as warm as 34°C. They can also withstand salinities up to 33 ppt, but 15 ppt is the optimal salinity for larval growth. This hardiness allows them to do well in disturbed areas with heavy amounts of agricultural pollution. Schools are organized by size and make dramatic group movements within a lake circling each other in patterns or crossing over one another with no mixing of the two sizes. Feeding occurs in deep water but Mississippi silversides are a common prey choice and will quickly return to shallow areas for protection. Zooplankton is their main prey followed by copepods and cladocreans and peek feeding hours are 1 to 3 hours after daybreak and just before dusk.

Spawning occurs any time of the day in April-September when temperatures are between 15°C and 30°C. Groups of males wait in beds of aquatic vegetation for a school of females to pass and then chase after a single or pair of females. The males will nip at her swollen abdomen until she settles into the vegetation bed where the group quivers violently and releases eggs and milt together. The eggs are attached to the substrate and stay there on their own until they hatch 4-30 days later. The young are planktonic for several weeks until they join a larger school. They will grow to 8-10 cm in their first year and most die immediately after spawning in their 1st or 2nd summer. A single female could produce 200-2,000 eggs per day for 3 months in proper conditions but most die before that 3 month time is complete.

Links to Other Research
Watershed

Modoc Sucker

Scientific Name
Catostomus microps
Native
Native Species
Identification

Modoc sucker, spawning. Photo by Stewart Reid, Western Fishes, Ashland, OR.
Modoc sucker, spawning. Photo by Stewart Reid, Western Fishes, Ashland, OR.

 

 

  • Small sucker: usually less than 16 cm SL, maximum 28 cm SL
  • Short head (TL = 4-5x head length), small eyes
  • Subterminal mouth with fleshy lips
  • Upper lip has 2-4 continuous rows of papillae
  • Lower lip has deep medial notch, 5-6 rows of papillae, 1 row connects two halves of lower lip
  • Coloration: deep gray to greenish brown, yellow to white underside
  • Breeding males: orange-red lateral band, orange fins, tubercles on body and fins
  • Breeding females, less colorful, lack tubercles
  • Lateral line scales (small): 79-89
Life History

Modoc suckers inhabit the cool (<25°C) pools of headwater streams that usually have high spring flows and low summer flows. Favorable streams have moderate gradients with large mud or rock bottomed pools where the suckers can seek refuge during summer. Within a pool the younger fish tend to stay in shallow water while larger fish seek cover in the deepest holes. Modoc suckers are commonly found in association with rainbow trout, speckled dace, Pit-Klamath brook lampreys, California roach, and Pit sculpin. Their populations may be adversely affected by the presence of predators like pikeminnow and brown trout. Modoc suckers feed primarily on detritus and algae, at which they are adept, though they may also feed on insect larvae and crustaceans found on soft substrates and aquatic vegetation. They undergo the most rapid growth during their 1st year and typically don’t exceed 15 cm SL in a 4 year life span (5 years max.). Modoc suckers reach sexual maturity at age 3 and have a relatively high fecundity for their body size. When snow-melt increases flows in mid-April to early June, Modoc suckers move up into tributary streams where water temperatures are in the range of 13-16°C. Spawning males arrive at gravelly riffles first and await the females. From mid-morning to late afternoon the females release some 6,400 to 12,600 eggs while 2-3 males simultaneously release their milt. The fertilized eggs fall into the spaces and crevices of the substrate where they incubate.

Links to Other Research
Watershed
  • Goose Lake Watershed
  • Upper Pit Watershed

Mountain Sucker

Scientific Name
Catostomus platyrhynchus
Native
Native Species
Identification

Mountain sucker. Photo courtesy of Professor Peter B. Moyle.
Mountain sucker. Photo courtesy of Professor Peter B. Moyle.

  • Small, fusiform sucker, up to 23 cm TL
  • Subterminal mouth, fleshy lips with papillae
  • Upper and lower lips notched at lateral margins, lower lip has median “cleft”
  • Front of upper lip lacks papillae
  • Lower lip lacks papillae in two semi-circles on inner margin, cartilaginous scraper may be evident
  • Coloration: Brown to olive back and sides, white to yellow underside, lateral band of splotches usually present
  • Mature males: dark red-orange lateral band above black-green lateral band
  • Spawning males: red-orange fins present, breeding tubercles cover entire body and all fins except dorsal, tubercles prominent on anal fin
  • Spawning females: tubercles present on back and sides of head and body
  • Fin rays: dorsal 8-13, pelvic 9
  • Lateral line scales: 75-92
Life History

 

Mountain suckers are appropriately named as these fish are found predominately in cool mountain streams with a temperature range of 1-28°C. In California the mountain sucker is native to several drainages on the eastern slope of the Sierra, though it has also been found in the Feather River watershed. They are usually found in clear mountain streams with a moderate gradient and a stream substrate composed of boulders, sand, or rubble. Mountain suckers also live in large rivers, turbid streams, and lakes. In California they are often found in association with Tahoe suckers and speckled dace, though the mountain sucker typically isolates itself form other sucker species. Within a stream mountain suckers favor pools with ample cover in the form of logs, overhanging banks, and aquatic vegetation. Juveniles feed on algae, diatoms, insects, and other aquatic invertebrates whereas adults tend to consume a smaller proportion of insects. The growth rate of the mountain sucker is greatest in the first year of life with females eventually reaching larger sizes than the male suckers. Male suckers reach sexual maturity in year 2-3 of a maximum 7 year life span, and females reach sexual maturity in year 3-4 of a possible 9 year life span. Spawning happens between June and early August in gravelly riffles of small streams when suckers move into those reaches to feed on algae. The act of spawning likely occurs at night when water temperatures are in a range of 11-19°C. Fertilized eggs fall into and adhere to the spaces between the gravel composite.

Links to Other Research
Watershed
  • East Branch North Fork Feather Watershed
  • East Walker Watershed
  • Honey-Eagle Lakes Watershed
  • Lake Tahoe Watershed
  • Middle Fork Feather Watershed
  • North Fork Feather Watershed
  • Truckee Watershed
  • Upper Carson Watershed
  • West Walker Watershed

Mountain Whitefish

Scientific Name
Prosopium williamsoni
Native
Native Species
Identification

Mountain whitefish. Location: Lower Truckee River, NV. Date: Oct. 2007. Photo by Marianne Denton, Department of Natural Resources and Environmental Science, University of Nevada, Reno.
Mountain whitefish. Location: Lower Truckee River, NV. Date: Oct. 2007. Photo by Marianne Denton, Department of Natural Resources and Environmental Science, University of Nevada, Reno.

  • Slim, cylindrical body, maximum 51 cm FL, (2.9kg)
  • Adipose fin present, large scales, forked tail
  • Short head, narrow snout overhangs mouth
  • Small ventral mouth: no teeth
  • Olive to dusky back, silvery body
  • Juveniles: 7-11 dark parr marks
  • Breeding males: nuptial tubercles on sides and head
  • Fin rays: anal 11-13, pelvic 10-12, pectoral 14-18
  • Lateral line scales: 74-90

 

Life History

Mountain whitefish typically live in clear cold waters, and primarily at high elevations in California. Favorable habitat might include mountain lakes or mountain streams with deep pools (>1 m) where summer temperatures range from 11-21°C. Mountain whitefish are found in Lake Tahoe where they swim in schools of 5-20 fish and occupy relatively deep water. Mountain whitefish generally use their ventral mouth to feed on bottom dwelling insects in both streams and lakes. They may use their tail or fins to stir up prey from the substrate. Mountain whitefish increase the diversity of their diet as they grow and tend to feed on the most abundant food organisms. Juvenile mountain whitefish in one stream may feed on mayfly, blackfly, and chironomid midges, while in another stream they may focus on mayfly and caddisfly larvae. In Lake Tahoe mountain whitefish eat a wide variety of bottom oriented invertebrates. Peak feeding occurs at dawn and dusk, though some whitefish may feed on terrestrial insects during daylight hours. Growth in mountain whitefish is variable, though generally growth rates are greater in large low-elevation streams than in small alpine lakes. Mountain whitefish reach sexual maturity in 2-4 years and spawning occurs between October and early December when water temperatures are below 11°C. Migration to favorable spawning gravels may be a short trip to a riffle or might include movement from a lake up into a small tributary. Large groups of mountain whitefish gather above rocky or gravelly substrate at night when females release an average of 5,500 eggs. The fertilized eggs fall into the spaces between the gravel and rocks and the eggs hatch in 6-10 weeks. The hatchlings are carried downstream to slower backwater areas. When the fry grow larger they move into deeper and faster water. In lakes young fry hide under aquatic vegetation.

Links to Other Research
Watershed
  • East Walker Watershed
  • Lake Tahoe Watershed
  • Truckee Watershed
  • Upper Carson Watershed
  • West Walker Watershed

Mozambique Tilapia

Scientific Name
Oreochromis mossambicus
Native
Non-Native
Identification

Mozambique tilapia hybrid, male, observed in the Salton Sea on 10/05/06. Photo by Sharon Keeney, California Department of Fish and Game. Note: this is a California Mozambique tilapia hybrid (Oreochromis mossambicus x O. urolepis hornorum).
Mozambique tilapia hybrid, male, observed in the Salton Sea on 10/05/06. Photo by Sharon Keeney, California Department of Fish and Game. Note: this is a California Mozambique tilapia hybrid (Oreochromis mossambicus x O. urolepis hornorum).

Mozambique tilapia hybrid, female (top) and male (bottom), captured from the Salton Sea in 2006. Photo by Sharon Keeney, California Department of Fish and Game. Note: these are tilapia hybrids (O. mossambicus x O. urolepis hornorum).
Mozambique tilapia hybrid, female (top) and male (bottom), captured from the Salton Sea in 2006. Photo by Sharon Keeney, California Department of Fish and Game. Note: these are tilapia hybrids (O. mossambicus x O. urolepis hornorum).

  • Deep, elongate, laterally compressed body
  • 29-33 cycloid scales on the lateral line
  • Bluntly pointed snout with a slightly oblique mouth that extends past the outer margins of the eye
  • 14-18 spines and 7-13 rays on the dorsal fin
  • 2-5 spines and 6-13 rays on the anal fin
  • 14-15 rays on the pectoral fin
  • Rounded caudal fin
  • Females and non-breeding males are normally a pale gray to washed-out yellow with 3-4 dark spots on their side
  • Normal coloration also includes caudal fin with distinctive stripes, dorsal fin with a gray to black margin often suffused with red
  • Spawning males have enlarged mouths and blue, thickened upper lips, black bodies, with mottling or an iridescent blue tinge, a pale throat and lower portion of the head, black dorsal fins with a red border, red pectoral fins, and a caudal fin with a wide red band at the end
Life History

Mozambique tilapia are commonly found in warm weedy ponds, canals, and river backwaters. A somewhat unique population is found in the Salton Sea where they are most common along the shore and in estuaries. They can survive in temperatures as low as 5.5°C for short periods but below 15°C they become sluggish and are easily infected by fungus and parasites. A couple of days in these conditions is almost always lethal. Anything above 37°C is usually also lethal making the optimum temperature for growth between 25°C and 30°C. Mozambique tilapia can also survive in salinities as high as 120 ppt and even reproduce in salinities as high as 69 ppt. Males are usually found in soft bottomed areas ideal for nest construction while females and young stay in areas with harder bottoms and more food. This food is usually made up of planktonic algae, aquatic plants, detritus, invertebrates, and even other fish if they are available. Zooplankton are especially important to juveniles. While Mozambique tilapia have often been used as a method of weed control it is believed that this omnivorous diet and the large size of male territories limits the Mozambique tilapia from being useful in this regard.

Mozambique tilapia mature at 6-14 cm in length and can breed continuously in temperatures over 20°C. Spawning occurs when a male claims a territory 15-140 cm in diameter and digs a shallow pit for a nest. He then displays in front of the female school convincing a female to follow him back to the nest. The pair will swim in circles before the female first deposits 100-600 eggs onto the nest and then takes them into her mouth. The male responds by releasing his milt which the female also takes into her mouth to fertilize the eggs. Once this process is complete the male chases that female away and begins displaying for another. The female incubates the eggs in her mouth for 11-12 days at which point she ejects her already free swimming offspring into the water. The young stay with their mother for 4-8 days during which time they can retreat to the safety of her mouth when a predator approaches. At the end of this period the young form massive schools in shallow water while the female returns to the adult school to find another mate. She can spawn again in 10-30 days. The young can grow as fast as 25-61 mm per month in ideal experimental situations but in more natural settings they usually reach 16-18 cm in 3-5 years. The largest individual recorded in California was 38 cm in length.

Links to Other Research
Watershed

Nile Tilapia

Scientific Name
Oreochromis niloticus
Native
Non-Native
Identification

missing fish photo

  • Deep, elongate, laterally compressed bodies
  • 30-34 cycloid scales on the lateral line
  • Bluntly pointed snout with a slightly oblique mouth that rarely extends past the outer margins of the eye
  • 15-18 spines and 12-14 rays on the dorsal fin
  • 3 spines and 7-12 rays on the anal fin
  • Truncate caudal fin
  • Females and non-breeding males are normally a pale gray to washed out yellow with a series of bands on the side
  • Normal coloration also includes caudal fin with distinctive stripes, dorsal fin with a gray to black margin often tinted with red
  • Spawning males are flushed with red throughout the head and sides
Life History

No definitive information is currently available for wild Nile tilapia in California. It is a common species for aquaculture farming where they are likely to have escaped from into the Colorado River. They can survive temperatures as high as 39-40°C but are less tolerant of high salinities than other tilapia. Fry will start on a diet of zooplankton and small insects but will become almost completely herbivorous when the reach 5-6 cm. As they get larger their diet will focus on phytoplankton like cyanobacteria but will also include bacteria, aquatic plants, and the small invertebrates that can be found on such plants.

 

Nile tilapia reach maturity when they are 18-30 cm in length and breeding begins when temperatures pass 18-19°C. Spawning occurs when males claim a territory and dig a shallow pit for a nest. He then displays in front of the female school convincing a female to follow him back to the nest. The pair will swim in circles before the female first deposits her eggs onto the nest and then takes them into her mouth. The male responds by releasing his milt which the female also takes into her mouth to fertilize the eggs. Once complete the male chases that female away and begins displaying for another. The female incubates the eggs in her mouth until they hatch and keeps the young there until they are free swimming and capable of being released into the water. The young stay with their mother for a few days after release during which time they can retreat to the safety of her mouth when a predator approaches. At the end of this period the young form massive schools in shallow water while the female returns to the adult school to find another mate. Nile tilapia are known to reach lengths of 40-65 cm and weights of 4-7 kg.

Links to Other Research
Watershed

Northern Pike

Scientific Name
Esox lucius
Native
Non-Native
Identification

Northern pike, captured from Lake Davis, CA. Photo by Robert Vincik, California Department of Fish and Game.
Northern pike, captured from Lake Davis, CA. Photo by Robert Vincik, California Department of Fish and Game.

Northern Pike caught in Seneca Lake, New York in September 2007. Photo by Arthur Masloski.
Northern Pike caught in Seneca Lake, New York in September 2007. Photo by Arthur Masloski.

Northern pike (group), captured from Lake Davis, CA. Photo by Robert Vincik, California Department of Fish and Game.
Northern pike (group), captured from Lake Davis, CA. Photo by Robert Vincik, California Department of Fish and Game.

  • Elongate, cylindrical, body with a strongly flattened snout half the length of the head
  • Mouth lined with sharp teeth and extending past the middle of the eye
  • Lower jaw extends past upper and contains large canine-like teeth
  • 105-148 fine cycloid scales on the lateral line
  • Slimy while alive
  • Forked tail
  • 15-19 dorsal, 12-15 anal, 14-17 pectoral, and 10-11 pelvic fin rays
  • Dark olive or grey on back and sides with a white to yellow belly, and typically rows of light oval spots on the side and head
  • Paired fins are normally tinged orange, and median fins commonly contain black splotches
  • Juveniles often have dark oblique lines running down their side

 

Life History

 

 

Northern Pike are commonly found in a variety of habitats including cool clear lakes, sluggish streams, and river backwaters, provided they have abundant shallow water (less than 4 m) and large amounts of vegetation growth. As they get older and larger northern pike will move towards the edges of the vegetation beds and into deeper water. This movement brings with it a drop in temperature down to as low as 1-4°C. The species’ lethal maximum temperature is believed to be 28-30°C. They are most common in freshwater areas but northern pike are capable of living in salinities as high as 10 ppt and breeding in areas up to 7 ppt.

Outside of breeding times northern pike are solitary creatures that patrol non-territorial home ranges for food. The northern pike is a sight-based, ambush hunter, taking advantage of clear water and thick vegetation to see and hide from its prey respectively. When prey passes in front of its hiding spot the northern pike will shoot forward, propelled by both its strong fins and a stream of water squeezed from its bucchal cavity, catching its target in its protruding jaws. In order to further disguise themselves, northern pike will defecate outside of their ranges in order to minimize the presence of fear scent that certain prey species have evolved to avoid. The type of prey pursued changes with the northern pike’s size. Fry will hunt mostly zooplankton, amphipods, and increasingly large benthic invertebrate larvae. By the time northern pike reach 25 cm, other fish, especially soft-rayed fish, make up the majority of their diet. Despite this preference, the northern pike is an opportunistic species, and frogs, snakes, mammals, and birds have all been found in northern pike stomachs.

Pike will mature in their second to third year when they are between 30 cm and 50 cm in length. Spawning occurs between February and April, when temperatures are between 5°C and 19°C. Shallow areas with dense vegetation beds are the preferred spawning location and some individuals will travel as much as 50 km to spawn in a suitable location. This search is aided by a homing ability that leads them to either their birthplace or locations where they have safely spawned before. Spawning may also occur in deeper areas if the near shore zone is too warm. Males arrive at spawning areas first and will rush in groups to court the females as they enter the area. A female will then release 5-60 eggs which are fertilized by the courting males as they fall before adhering to the vegetation below. Fecundity varies with size and age but in Lake Davis Reservoir, in the Feather River watershed, 3 year old females weighing 2.1-2.5 kg could produce between 30,000 and 80,000 eggs a season.

The embryos hatch in 12-14 days but the larvae stay attached to the plant body for another 4-15 days until they grow to approximately 10-12 mm and begin feeding within the spawning area. They will stay in this bed until they grow to approximately 20 cm, at which point they disperse by their own power or on the currents of increased stream flow. In their native ranges average growth rates put northern pike at 18 cm by their first year, 32 cm in their second, and 42 cm in their third, but California populations have consistently averaged higher growth rates (23 cm, 39 cm, and 53 cm in the first, second, and third years, respectively). Few individuals live past 10-12 years and 7 years old is a common maximum. The largest individual on record was a 29 year old Canadian fish that measured 110 cm and weighed 14.2 kg.

Links to Other Research
Watershed

Owens Pupfish

Scientific Name
Cyprinodon radiosus
Native
Native Species
Identification

Owens pupfish, male. Location: Fish Slough, CA. Photo by Joe Ferreira, California Department of Fish and Game.
Owens pupfish, male. Location: Fish Slough, CA. Photo by Joe Ferreira, California Department of Fish and Game.

Owens pupfish, male (blue) and female (brown). Photo by Stacey Brown, MD. If you look closely you can find at least 5 additional females and 3 males.
Owens pupfish, male (blue) and female (brown). Photo by Stacey Brown, MD. If you look closely you can find at least 5 additional females and 3 males.

 

  • Small, deep bodied, up to 65 mm TL
  • Large eyes, terminal mouth, protrusible lips
  • Large scales, spines absent on circuli, interspaces between circuli reticulated
  • First dorsal ray thick, equidistant from base of tail and tip of snout
  • Sexual dimorphism present: males larger and deeper bodied
  • Breeding males: bright blue, purple lateral bars
  • Females: olive brown with purple sheen, lateral blotches and bars present
  • Fin rays: dorsal 10-12, anal 9-12, pectoral 13-17, pelvic 6-8, caudal 16-19
  • Lateral series scales: 26-27
Life History

Owens pupfish historically occupied a variety of shallow water locations in the Owens Valley. Typical waters included spring pools, sloughs, and irrigation ditches. Such water bodies were characterized by shallow clear water, and by the presence of emergent and aquatic vegetation. Historical water temperatures probably ranged from 10 to 25°C and associated species would have included Owens speckled dace, Owens tui chub, and Owens suckers. Today Owens pupfish are found in a limited number of refuges where the water is clear and primarily shallow, and where predators are limited. They forage in shoals of 30-50 fish, feeding mostly on aquatic organisms like crustaceans, snails, chironomid midge larvae, etc. During the nighttime and winter months pupfish are sedentary and rest on or in the substrate. Within one year Owens pupfish reach adult size and begin breeding, rarely living more than two years total. Spawning seasons vary between locations. In some places spawning might begin in February and end by late June but in locations affected by large seasonal temperature fluctuations spawning typically begins in March and lasts through August. Spawning behavior involves both courtship and competition. Non-territorial males might initiate breeding while territorial males stick to a specific area near shore. Females remain under the cover of vegetation till they are ready to spawn, and spawning commences over different kinds of substrate including silt, plants, or rocks. Female Owens pupfish may engage with a potential mate up to 200 times in one day, though 60-70% of courtship fails to result in an egg. A successful spawn results in 1 or 2 fertilized eggs. The eggs hatch in 4-10 days at 24-27°C. Emerging larvae and subsequent juveniles tend to remain close to the stream substrate.

Links to Other Research
Watershed
  • Crowley Lake Watershed
  • Owens Lake Watershed

Owens Sucker

Scientific Name
Catostomus fumeiventris
Native
Native Species
Identification

Owens sucker, underwater. Location: Hot Creek, CA. Photo by Joe Ferreira, California Department of Fish and Game.
Owens sucker, underwater. Location: Hot Creek, CA. Photo by Joe Ferreira, California Department of Fish and Game.

Owens sucker. Location: Hot Creek, CA. Photo by Joe Ferreira, California Department of Fish and Game.
Owens sucker. Location: Hot Creek, CA. Photo by Joe Ferreira, California Department of Fish and Game.

Owens sucker, ventral view. Location: Hot Creek, CA. Photo by Joe Ferreira, California Department of Fish and Game. Note: the scientific name of this species, fumeiventris, means
Owens sucker, ventral view. Location: Hot Creek, CA. Photo by Joe Ferreira, California Department of Fish and Game. Note: the scientific name of this species, fumeiventris, means "smoky belly".

 

  • Usually
  • Large head, long snout, thick caudal peduncle, coarse scales
  • Subterminal mouth: lower lip with deep median cleft and prominent papillae
  • Coloration: dusky to smoky underside, may have blue iridescence on sides, slate-colored back
  • Breeding adults: reddish stripe on sides, reddish-amber color may be present on paired fins
  • Fin rays: pectoral 16-19, dorsal 10, pelvic 9-10
  • Lateral line scales: 66-85, 13-16 rows above line, 9-11 rows below line
Life History

Owens suckers occupy waters in southeastern California and specifically in the Owens Valley. The species has been introduced into June Lake (Mono Lake Basin) and the Santa Clara River drainage (via the Owens Aqueduct). They are primarily found in long stretches of soft-bottomed runs in cool-water streams. They also inhabit the bottoms of lakes and reservoirs. Owens suckers feed at night on a diet of aquatic insects, algae, detritus, and organic matter. Their life history is similar to the Tahoe sucker and they spawn from early May through early July. Like other suckers, Owens suckers probably spawn in groups over gravel substrate. Larval suckers become juveniles at a total length of 19-22 mm and hide under cover along stream margins and in backwaters.

Links to Other Research
Watershed
  • Crowley Lake Watershed
  • Mono Lake Watershed
  • Owens Lake Watershed
  • Santa Clara Watershed

Pacific Lamprey

Scientific Name
Lampetra tridentata
Native
Native Species
Identification

Pacific lamprey, captured in rotary screw trap on Sacramento River at Knight's Landing. Photo by Dan Worth, California Department of Fish and Game.
Pacific lamprey, captured in rotary screw trap on Sacramento River at Knight's Landing. Photo by Dan Worth, California Department of Fish and Game.

Pacific lamprey (mouth), captured in rotary screw trap on Sacramento River at Knight's Landing. Photo by Robert Vincik, California Department of Fish and Game.
Pacific lamprey (mouth), captured in rotary screw trap on Sacramento River at Knight's Landing. Photo by Robert Vincik, California Department of Fish and Game.

Pacific lamprey juvenile (albino), captured in rotary screw trap on Sacramento River at Knight's Landing. Photo by Robert Vincik, California Department of Fish and Game.
Pacific lamprey juvenile (albino), captured in rotary screw trap on Sacramento River at Knight's Landing. Photo by Robert Vincik, California Department of Fish and Game.

  • Largest of CA lampreys, commonly exceed 40 cm TL, dwarfs exist
  • Two dorsal fins, slightly separated, 2nd dorsal continuous with caudal fin
  • Body segments (myomeres): 62-71
  • Males: taller dorsal fins, anal fin absent, may possess small genital papillae
  • Females: short dorsal fins, possess anal fin
  • Larvae: 68-70 segments between anus and last gill opening, dark back and lower oral hood
  • Newly morphed adults silvery in color
  • Spawning adults: dark greenish black
  • Oral disc 6-8% of TL
  • Sucking disc full of horny plates
  • Supraoral lamina has 1 small center cusp and 2 larger lateral cusps
  • Inner lateral plates (4) on each side: middle 2 tricuspid, outer 2 bicuspid
  • Tongue ends in 14-21 small points, center point largest

 

Life History

 

Pacific lampreys are usually anadromous with two very distinct parts of their life cycle, though some landlocked forms of lamprey exist. Pacific lampreys begin their life cycle as an ammocoete or larvae, usually within a freshwater stream. Ammocoetes burrow tail first into mud or soft substrate where they filter feed on algae and organic matter. The larval lampreys often move around the stream in their 5-7 year stay in freshwater. When the ammocoetes reach a length of around 14-16 cm TL they begin a drastic change in physiology and physical appearance. The larval lampreys take on a silvery form with large eyes and a sucking disc. The newly morphed lampreys swim downstream to the Pacific Ocean where they take on a new predatory lifestyle in an estuarine or saltwater environment. Lampreys rarely stray far from the mouth of their home stream. Pacific lampreys attack and feed on fish including salmon and flatfish. The stay at sea usually lasts 3-4 years in Canada but may be shortened in more southern populations. Like salmon, the lampreys return to freshwater and migrate upstream to spawn and die. Most upstream movement occurs during the night under high flow conditions, and some streams have different runs of lampreys. Runs may be different in the timing of entry to freshwater or in the amount of time spent in freshwater before breeding occurs. Breeding males and females dig a nest in moderately swift water by removing rock and gravel from the stream floor. A female will attach herself to a rock upstream of the nest, and the male will attach himself to the female or to a nearby anchor. The female releases 20,000 to 200,000 eggs in total, and the male releases his milt. The nest is then covered by stirring the substrate upstream of the fertilized eggs. Often one female will have her eggs fertilized by multiple males, as individual nests may be constructed in close proximity to others. Usually the male and female then die, though studies have shown that some adult lampreys live to spawn again the following year. The embryos hatch after roughly 19 days, and the resulting ammocoetes often stay within the safety of the gravel substrate before venturing into the current.

Links to Other Research
Watershed
  • Alisal-Elkhorn Sloughs Watershed
  • Applegate Watershed
  • Big-Navarro-Garcia Watershed
  • Bodega Bay Watershed
  • Butte Watershed
  • Calleguas Watershed
  • Carmel Watershed
  • Central Coastal Watershed
  • Chetco Watershed
  • Cottonwood Headwaters Watershed
  • Coyote Watershed
  • Cuyama Watershed
  • Estrella Watershed
  • Goose Lake Watershed
  • Gualala-Salmon Watershed
  • Honcut Headwaters Watershed
  • Illinois Watershed
  • Los Angeles Watershed
  • Lost Watershed
  • Lower American Watershed
  • Lower Bear Watershed
  • Lower Butte
  • Lower Cache Watershed
  • Lower Calaveras-Mormon Slough Watershed
  • Lower Cosumnes-Lower Mokelumne Watershed
  • Lower Cottonwood Watershed
  • Lower Eel Watershed
  • Lower Feather Watershed
  • Lower Klamath Watershed
  • Lower Sacramento Watershed
  • Lower Yuba Watershed
  • Mad-Redwood Watershed
  • Mattole Watershed
  • Middle Fork Eel Watershed
  • Middle San Joaquin-Lower Chowchilla Watershed
  • Middle San Joaquin-Lower Merced-Lower Stanislaus Watershed
  • Mill Watershed
  • Mill-Big Chico Watershed
  • Pajaro Watershed
  • Russian Watershed
  • Sacramento-Lower Cow-Lower Clear Watershed
  • Sacramento-Lower Thomes Watershed
  • Sacramento-Stone Corral Watershed
  • Salinas Watershed
  • Salmon Watershed
  • San Antonio Watershed
  • San Diego Watershed
  • San Francisco Bay Watershed
  • San Francisco Coastal South Watershed
  • San Joaquin Delta Watershed
  • San Lorenzo-Soquel Watershed
  • San Pablo Bay Watershed
  • Santa Ana Watershed
  • Santa Barbara Coastal Watershed
  • Santa Clara Watershed
  • Santa Margarita Watershed
  • Santa Maria Watershed
  • Santa Monica Bay Watershed
  • Santa Ynez Watershed
  • Scott Watershed
  • Seal Beach Watershed
  • Shasta Watershed
  • Smith Watershed
  • South Fork Eel Watershed
  • South Fork Trinity Watershed
  • Suisun Bay Watershed
  • Tomales-Drake Bays Watershed
  • Trinity Watershed
  • Upper Butte
  • Upper Cache Watershed
  • Upper Coon-Upper Auburn Watershed
  • Upper Cosumnes Watershed
  • Upper Cow-Battle Watershed
  • Upper Eel Watershed
  • Upper Elder-Upper Thomes Watershed
  • Upper Klamath Watershed
  • Ventura Watershed

Pacific Staghorn Sculpin

Scientific Name
Leptocottus armatus
Native
Native Species
Identification

Pacific staghorn sculpin, at Corona del Mar, CA on 22 May 2007. Photo by  Jonathan S. Klenk, PADI IDCS 179360.
Pacific staghorn sculpin, at Corona del Mar, CA on 22 May 2007. Photo by Jonathan S. Klenk, PADI IDCS 179360.

Pacific staghorn sculpin caught in Suisun Marsh, CA on 20 August 2008. Photo by Amber Manfree.
Pacific staghorn sculpin caught in Suisun Marsh, CA on 20 August 2008. Photo by Amber Manfree.

Pacific staghorn sculpin (head) caught in Suisun Marsh, CA on 20 August 2008. Note the large, branched spine (the
Pacific staghorn sculpin (head) caught in Suisun Marsh, CA on 20 August 2008. Note the large, branched spine (the "stag horn" or "antler") on each operculum, raised in defense. Photo by Amber Manfree.

  • 12-15 cm SL at maturity, typically at age 1
  • Large flat head, small eyes, gill covers extend into antler-like projections with 3-4 spines, narrow caudal peduncle
  • Long jaw extends ahead of eyes and bears significant teeth
  • Fin rays: pelvic 4, 1st dorsal 7 spines, 2nd dorsal 17 rays, anal 17 rays
  • Smooth skin is grayish olive on back, yellow on sides, white on underside
  • 1st dorsal fin has dark splotch on tail end, other fins have bars

 

Life History

 

The Pacific staghorn sculpin spend most of their lives in salt and brackish waters, though they are capable of adapting to fresh water as well as extremely saline waters. The larvae begin their lives in the estuary where they spread out onto a soft and sandy substrate. As they develop into juveniles, the young fish depart in many directions including into freshwater. Most fish found in freshwater or less salty areas are the young juveniles which feed on amphipods, invertebrates, small fish, and aquatic insect larvae. The older Pacific staghorn sculpins tend to be the farthest upstream, giving way for more young fish to push up from the marine or estuary environments. The marine dwelling fish may follow the tide and have a diet of crabs, shrimp, and fish. Most Pacific staghorn sculpins feed actively at night, though they may eat throughout the day. Throughout the west coast spawning occurs in saltwater or brackish water from October to April, though in California the Pacific staghorn sculpin spawn in January and February.

Links to Other Research
Watershed
  • Alisal-Elkhorn Sloughs Watershed
  • Aliso-San Onofre Watershed
  • Big-Navarro-Garcia Watershed
  • Bodega Bay Watershed
  • Calleguas Watershed
  • Carmel Watershed
  • Central Coastal Watershed
  • Chetco Watershed
  • Cottonwood Tijuana Watershed
  • Coyote Watershed
  • Gualala-Salmon Watershed
  • Los Angeles Watershed
  • Lower Eel Watershed
  • Lower Klamath Watershed
  • Lower Sacramento Watershed
  • Mad-Redwood Watershed
  • Mattole Watershed
  • Newport Bay Watershed
  • Pajaro Watershed
  • Russian Watershed
  • Salinas Watershed
  • Salmon Watershed
  • San Antonio Watershed
  • San Diego Watershed
  • San Francisco Bay Watershed
  • San Francisco Coastal South Watershed
  • San Gabriel Watershed
  • San Joaquin Delta Watershed
  • San Lorenzo-Soquel Watershed
  • San Luis Rey-Escondido Watershed
  • San Pablo Bay Watershed
  • Santa Ana Watershed
  • Santa Barbara Coastal Watershed
  • Santa Clara Watershed
  • Santa Margarita Watershed
  • Santa Maria Watershed
  • Santa Monica Bay Watershed
  • Santa Ynez Watershed
  • Seal Beach Watershed
  • Smith Watershed
  • Suisun Bay Watershed
  • Tomales-Drake Bays Watershed
  • Ventura Watershed

Paiute Sculpin

Scientific Name
Cottus beldingi
Native
Native Species
Identification

Paiute sculpin (lateral view)  from Sagehen Creek, CA in 2012. Photo by Matt Young.
Paiute sculpin (lateral view) from Sagehen Creek, CA in 2012. Photo by Matt Young.

Paiute sculpin (frontal view)  from Sagehen Creek, CA in 2012. Photo by Matt Young.
Paiute sculpin (frontal view) from Sagehen Creek, CA in 2012. Photo by Matt Young.

Paiute sculpin in Sagehen Creek, CA in 2012. Photo by Matt Young. See photo below for the location of this highly camouflaged fish.
Paiute sculpin in Sagehen Creek, CA in 2012. Photo by Matt Young. See photo below for the location of this highly camouflaged fish.

Paiute sculpin in Sagehen Creek, CA in 2012. Photo by Matt Young.
Paiute sculpin in Sagehen Creek, CA in 2012. Photo by Matt Young.

  • Large sizes rare, maximum 127 mm TL
  • Prickling absent, rounded caudal fin, separated dorsal fins, pelvic fins may extend past vent
  • Long maxillary: may extend past medial margin of eye
  • Pre-opercular spines (2): upper - long and slender, lower - inconspicuous
  • Median chin pores (2): rarely (1 or 0)
  • Coloration: variable, usually 4-5 vertical bands on sides, fins mottled or barred
  • Males: long anal papillae, width of mouth > distance between anus and pelvic fins
  • Females: width of mouth < distance between anus and pelvic fins
  • Fin spines/rays: 1st dorsal 6-8 spines, 2nd dorsal 13-16 rays, pectoral 14-15
  • Lateral line: incomplete, more than 23-35 pores
Life History

Paiute sculpins favor living on rubble or gravel in cold, moderate-gradient streams where water temperatures rarely exceed 20°C. They are also found living in lakes and surviving sustained temperatures in the range of 20-25°C where water flow is ample. Because Paiute sculpins typically live in the riffles of clear streams they are often found in association with trout. In Lake Tahoe Paiute sculpin are most often found in deepwater near aquatic macrophytes. In both stream and lake environments the sculpins feed primarily at night when they can more easily ambush and capture prey. Their diet in a stream may consist of aquatic insect larvae, aquatic beetles, snails, water mites, or algae. Dragonfly larvae are a focal point of feeding in meadow streams. Feeding in Lake Tahoe varies with the depth of the sculpin. Deep water dwellers feed on mostly detritus and algae, with other prey items supplementing their diet. Paiute sculpins in shallower regions eat primarily benthic organisms such as chironomid midge larvae. The feeding habits of Paiute sculpins vary with body size and seasonal changes, as certain prey are more available during specific time periods. They feed year-round with decreased consumption rates in fall and winter. Paiute sculpin reach sexual maturity in their 2nd or 3rd year, with spawning occurring primarily in May and June. Spawning sites are usually found where there is adequate rocky or gravelly substrate to hide nests. Presumably each female deposits her eggs in one nest to be fertilized. One study revealed mean fecundity in Lake Tahoe was 123 eggs per female, similar to egg production in Sagehen Creek, CA. When the fry hatch they remain within the nest for another 1-2 weeks, absorbing the yolk sac. The post-larval sculpins may then be washed away by downstream currents or littoral waves sometime in the following weeks. The success of Paiute sculpin has great variance and populations seem to thrive in the absence of winter flooding, though overall stream conditions may suffer.

Links to Other Research
Watershed
  • East Walker Watershed
  • Honey-Eagle Lakes Watershed
  • Lake Tahoe Watershed
  • Truckee Watershed
  • Upper Carson Watershed
  • West Walker Watershed

Pit Sculpin

Scientific Name
Cottus pitensis
Native
Native Species
Identification

Pit sculpin. Modoc County, CA. July 10, 2007.
Pit sculpin. Modoc County, CA. July 10, 2007.

Pit sculpin, head. Modoc County, CA. Date: July 10, 2007.
Pit sculpin, head. Modoc County, CA. Date: July 10, 2007.

  • Resembles riffle sculpin
  • Up to 127 mm SL
  • Pre-opercular spines (2), sometimes (3)
  • Median chin pore usually absent
  • Prickles present behind and above origin of pectoral fins
  • Coloration: variable, light underside
  • Dark dorsal saddles present (5-6): 2 below 1st dorsal, 3-4 below 2nd dorsal
  • Dark band may be present on caudal peduncle
  • Bands present on pectoral, caudal, and 2nd dorsal fins
  • Large blotch on back of 1st dorsal fin
  • Fin rays/spines: pectoral 12-16 rays, pelvic 3-4 rays/1 spine, 1st dorsal 8-9 spines, 2nd dorsal 16-19 rays, anal 12-15 rays
  • Lateral line: usually complete, 31-39 pores
Life History

 

Pit sculpins are found predominantly in streams with temperatures below 25°C and oxygen levels near saturation. These waterways include fast rocky streams, spring fed creeks, and large boulder filled rivers. Pit sculpins are usually found in swift currents in riffles or runs. In some rare cases Pit sculpins may share habitat with marbled and rough sculpins, and they are often found in association with rainbow trout, speckled dace, and Sacramento suckers. Pit sculpins feed mostly on aquatic insects throughout the day and night and may become aggressive at times. Peak feeding is typically in the early morning. Pit sculpins become sexually mature in their second year and the age-class population decreases with every passing year. The sculpins spawn in February through early May with most breeding occurring in late February and March. Male Pit sculpins develop dark breeding colors and an orange band on their dorsal fin. They entice females to lay eggs within their rock cave. Male Pit sculpins may fertilize the eggs of several females. The fertilized eggs stick to the substrate within the caches and eventually larval sculpins hatch, though they remain close to the cave for some time.

Links to Other Research
Watershed
  • Goose Lake Watershed
  • Lower Pit Watershed
  • Upper Pit Watershed

Pit-Klamath Brook Lamprey

Scientific Name
Lampetra lethophaga
Native
Native Species
Identification

Pit-Klamath brook lamprey adult (top) & ammocoete (bottom). Location:  Dry Creek, Lake County, Oregon. Date:  9/18/2007. Photo by Michael P. Heck, Oregon Department of Fish and Wildlife.
Pit-Klamath brook lamprey adult (top) & ammocoete (bottom). Location: Dry Creek, Lake County, Oregon. Date: 9/18/2007. Photo by Michael P. Heck, Oregon Department of Fish and Wildlife.

Pit-Klamath brook lamprey in Lassen Creek (Goose Lake), Modoc County, CA on 3 June 2009.  Each lamprey is holding on to the rock using its oral disc. Photo by Steve Howard.
Pit-Klamath brook lamprey in Lassen Creek (Goose Lake), Modoc County, CA on 3 June 2009. Each lamprey is holding on to the rock using its oral disc. Photo by Steve Howard.

Note: There is a chance that the lampreys in the photo above are dwarf Pacific lamprey, which are also present in Goose Lake.  The two species are very similar, and you would need to compare the oral discs and plates to tell them apart.

Pit-Klamath brook lamprey ammocoete. Date:  7/10/2007.
Pit-Klamath brook lamprey ammocoete. Date: 7/10/2007.

Pit-Klamath brook lamprey ammocoete head. Date: 7/10/2007.
Pit-Klamath brook lamprey ammocoete head. Date: 7/10/2007.

  • Small lamprey, < 21cm TL
  • Body segments (myomeres): 60-70
  • Adults: dark gray back, brass to bronze underside
  • Spawners: contrasting ventral/dorsal surfaces, 1 thick and frilled dorsal fin, enlarged anal fin
  • Oral disc < 5% of TL
  • Supraoral plate: 3 cusps, middle one may be missing
  • Lateral circumoral plates cusps 1-2-2-1 or 2-3-3-2
  • Posterior circumoral plates: 9-15, often 1 cusp
  • Cusps frequently missing from plates
  • Infraoral teeth: usually 5
Life History

 

The Pit-Klamath brook lamprey is a non-predatory lamprey that is closely related to the predatory Pacific lamprey, and often shares habitat with trout, marbled sculpins, rough sculpins, and speckled dace. Pit-Klamath brook lampreys are found within the Pit River drainage and the upper Klamath River upstream of the Klamath lakes. They are typically found in cool, clear, low gradient streams with sandy or muddy edges and bottoms. The larval lampreys or ammocoetes burrow tail first into the soft substrate where they feed on algae and detritus. The ammocoetes often burrow into areas covered by aquatic vegetation. After at least 4 years the ammocoetes metamorphose into the adult lamprey form, probably in the autumn. Spawning begins in the spring and may continue into the summer.

Links to Other Research
Watershed
  • Goose Lake Watershed
  • Lost Watershed
  • Lower Pit Watershed
  • Upper Pit Watershed

Porthole Livebearer

Scientific Name
Poeciliopsis gracilis
Native
Non-Native
Identification

Porthole livebearer, female. Location: Irrigation drain (Oasis-Grant) at the north end of the Salton Sea. Length: approximately 40 mm TL. Date: 5/20/2010. Photo by Sharon Keeney, California Department of Fish and Game.
Porthole livebearer, female. Location: Irrigation drain (Oasis-Grant) at the north end of the Salton Sea. Length: approximately 40 mm TL. Date: 5/20/2010. Photo by Sharon Keeney, California Department of Fish and Game.

Porthole livebearer, two females. Location: Irrigation drain (Oasis-Grant) at the north end of the Salton Sea. Length: approximately 40 mm TL. Date: 5/20/2010. Photo by Sharon Keeney, California Department of Fish and Game.
Porthole livebearer, two females. Location: Irrigation drain (Oasis-Grant) at the north end of the Salton Sea. Length: approximately 40 mm TL. Date: 5/20/2010. Photo by Sharon Keeney, California Department of Fish and Game.

Porthole livebearer, female, left side. Location: Irrigation drain (Oasis-Grant) at the north end of the Salton Sea. Length: approximately 40 mm TL. Date: 5/20/2010. Photo by Sharon Keeney, California Department of Fish and Game.
Porthole livebearer, female, left side. Location: Irrigation drain (Oasis-Grant) at the north end of the Salton Sea. Length: approximately 40 mm TL. Date: 5/20/2010. Photo by Sharon Keeney, California Department of Fish and Game.

  • Chunky body with large eyes and a small head
  • Long gonopodium from rays of the anal fin extends nearly to the caudal fin
  • Rounded tail
  • Short dorsal fin entirely behind the base of the anal fin
  • 29 large scales on the lateral line
  • Pale brown and translucent with 3-8 large black spots running down each midline usually on the rear of the body

 

Life History

Most information about the porthole livebearer is gathered from aquarium fish but wild populations are known to exist near the Salton Sea. They have been found in drains with salinities up to 18 ppt and temperatures as high as 26-28°C and seem to prefer shallow, flowing waters. They are an omnivorous species and will eat from both the bottom and water column of their chosen area. Most only live to be a year old, growing to approximately 75 mm. Males are mature by the time they are 22-25 mm and will defend small territories to attract females. Females do not mature until they reach 36 mm in length. Females can hold between 1 and 140 embryos at a time and can reproduce all year long in the right conditions. In the Salton Sea these conditions are only found during the summer and therefore reproduction does not occur during the winter in California.

Links to Other Research
Watershed

Prickly Sculpin

Scientific Name
Cottus asper
Native
Native Species
Identification

Prickly sculpin, approximately 10 cm (4”) long. Location: Suisun Marsh, California. Date: 8/6/2007.
Prickly sculpin, approximately 10 cm (4”) long. Location: Suisun Marsh, California. Date: 8/6/2007.

Prickly sculpin (anterior view), captured in rotary screw trap on the Sacramento River at Knight's Landing on 2/26/2009. Photo by Dan Worth, California Department of Fish and Game.
Prickly sculpin (anterior view), captured in rotary screw trap on the Sacramento River at Knight's Landing on 2/26/2009. Photo by Dan Worth, California Department of Fish and Game.

Prickly sculpin (dorsal view), captured in rotary screw trap on the Sacramento River at Knight's Landing on 2/26/2009. Photo by Dan Worth, California Department of Fish and Game.
Prickly sculpin (dorsal view), captured in rotary screw trap on the Sacramento River at Knight's Landing on 2/26/2009. Photo by Dan Worth, California Department of Fish and Game.

  • Maximum size in California is about 20 cm SL
  • Long anal fin (3 X longer than caudal peduncle)
  • Long dorsal fins connected at base
  • Palatine teeth usually visible, single chin pore (sometimes 2), 2-3 pre-opercular spines, 28-43 lateral line pores
  • Mottled reddish brown to dark brown coloring, 4-5 dark saddles, white to yellow underside
  • Fins often barred, 1st dorsal fin may have dark spot on posterior/tail side
  • Males have long v-shaped genital papilla
  • During breeding both sexes have dark coloring and orange leading edge on 1st dorsal fin
  • Fin rays/spines: anal 16-19 rays, 1st dorsal 7-10 soft spines, 2nd dorsal 19-23 rays, pectoral 15-18 rays
  • Pelvic fin "elements": 4 (1 spine, 4 rays, but the spine is fused with the 1st ray)
Life History

The prickly sculpin is adaptable to environments ranging from fresh to saltwater, and from small cool stream to large warm rivers and lakes. The prickly sculpin has a variety of forms as some are coastal, others live in the valley, and some are limited to Clear Lake proper. The coastal forms rarely live in a stream without an estuary and rarely go farther than 50 km upstream though they have been found present over 120 km upstream, often sharing habitat with the coastrange sculpin. In the Central Valley of California these fish inhabit low elevation waters. The limitation to the spread of these fish seems to be water quality, as the prickly sculpin is not found in highly polluted waters. In streams these fish use a variety of habitats though good cover or overhanging vegetation is a common thread. The prickly sculpin spends most of the day sedentarily hiding and they then becomes active in feeding and movement at night. When prickly sculpins reach sexual maturity after 2, 3, or 4 years they move to a suitable place in freshwater to spawn and hide the eggs under loose rock substrate. Most spawning occurs between February and June. The male will guard the fertilized eggs until they hatch. When the larvae emerge they are quickly washed downstream to an estuary or deep slow pool. In lakes and in estuaries the larvae become pelagic. As the larvae develop into juvenile fish they begin to move to area of prosperous feeding, often moving upstream a considerable distance. In many cases the movement of fish, and especially young prickly sculpin, is limited by man-made barriers or diversions. In lakes, juvenile prickly sculpin forage around the lake shores and then gradually move into deeper water as they grow.

Feeding patterns in the prickly sculpin vary depending upon geographical location and/or by size. For example in Clear Lake these fish may feed more consistently throughout the day. Both adults an juveniles eating midges and amphipods. While in coastal streams the food source includes benthic invertebrates, aquatic insects, and mollusks. Adult sculpins may supplement their diet with small fish and frogs.

 

Links to Other Research
Watershed
  • Alisal-Elkhorn Sloughs Watershed
  • Big-Navarro-Garcia Watershed
  • Bodega Bay Watershed
  • Carmel Watershed
  • Central Coastal Watershed
  • Chetco Watershed
  • Cottonwood Headwaters Watershed
  • Coyote Watershed
  • Gualala-Salmon Watershed
  • Lower American Watershed
  • Lower Butte
  • Lower Cache Watershed
  • Lower Calaveras-Mormon Slough Watershed
  • Lower Cosumnes-Lower Mokelumne Watershed
  • Lower Cottonwood Watershed
  • Lower Eel Watershed
  • Lower Feather Watershed
  • Lower Klamath Watershed
  • Lower Sacramento Watershed
  • Mad-Redwood Watershed
  • Mattole Watershed
  • Middle San Joaquin-Lower Chowchilla Watershed
  • Middle San Joaquin-Lower Merced-Lower Stanislaus Watershed
  • Mill Watershed
  • Newport Bay Watershed
  • Pajaro Watershed
  • Panoche-San Luis Reservoir Watershed
  • Russian Watershed
  • Sacramento-Lower Cow-Lower Clear Watershed
  • Sacramento-Lower Thomes Watershed
  • Sacramento-Stone Corral Watershed
  • Sacramento-Upper Clear Watershed
  • Salinas Watershed
  • Salmon Watershed
  • San Antonio Watershed
  • San Francisco Bay Watershed
  • San Francisco Coastal South Watershed
  • San Gabriel Watershed
  • San Joaquin Delta Watershed
  • San Lorenzo-Soquel Watershed
  • San Pablo Bay Watershed
  • Santa Ana Watershed
  • Santa Barbara Coastal Watershed
  • Santa Clara Watershed
  • Santa Maria Watershed
  • Santa Ynez Watershed
  • Seal Beach Watershed
  • Smith Watershed
  • South Fork Eel Watershed
  • South Fork Trinity Watershed
  • Suisun Bay Watershed
  • Tomales-Drake Bays Watershed
  • Trinity Watershed
  • Tulare-Buena Vista Lakes Watershed
  • Upper Cache Watershed
  • Upper Calaveras Watershed
  • Upper Chowchilla-Upper Fresno Watershed
  • Upper Cosumnes Watershed
  • Upper Cow-Battle Watershed
  • Upper Dry Watershed
  • Upper Kaweah Watershed
  • Upper King Watershed
  • Upper Merced Watershed
  • Upper Mokelumne Watershed
  • Upper Putah Watershed
  • Upper San Joaquin Watershed
  • Upper Stanislaus Watershed
  • Upper Tuolumne Watershed
  • Ventura Watershed

Pumpkinseed

Scientific Name
Lepomis gibbosus
Native
Non-Native
Identification

Pumpkinseed, captured from Lake Davis, CA. Photo by Robert Vincik, California Department of Fish and Game.
Pumpkinseed, captured from Lake Davis, CA. Photo by Robert Vincik, California Department of Fish and Game.

Pumpkinseed, caught in Seneca County, New York. Photo by Arthur Masloski, December 2008.
Pumpkinseed, caught in Seneca County, New York. Photo by Arthur Masloski, December 2008.

Pumpkinseed, captured at Lake Davis, CA. Photo by Dan Worth, California Department of Fish and Game.
Pumpkinseed, captured at Lake Davis, CA. Photo by Dan Worth, California Department of Fish and Game.

 

  • Deep body with small oblique mouth
  • Long pectoral fins
  • Short stiff opercular flaps
  • 10-12 dorsal, 9-11 anal, 5 pelvic, 12-13 pectoral fin rays
  • 10 dorsal, 3-4 anal, 1 pelvic spine(s)
  • Small spots on the soft part of the dorsal fin
  • Orange and blue streaks on the dark operculum
  • 36-44 scales on the lateral line
  • Gray-green to greenish brown body with orange, yellow, blue, and green spots, and 7-10 faint blue green vertical bands, yellow to orange throat and belly, and a cheek with a series of wavy blue lines
  • Juveniles are a more uniform gray-green with conspicuous vertical bars
Life History


Pumpkinseeds are most common in clear to slightly turbid lakes, sloughs, and sluggish streams with beds of aquatic plants and large snail populations. While lab results show preference for temperatures between 24°C and 32°C, wild populations tend to be more frequent in cooler areas. In these cooler areas they can survive with dissolved oxygen levels less than 1 mg/L but warmer waters require at least 4 mg/L in order to be habitable.  Pumpkinseeds can also survive in salinities up to 17 ppt. Hard-shelled invertebrates make up the majority of the pumpkinseed diet, with snails and clams from the bottom and aquatic plants being the most common targets. This is made possible by molar-like teeth that can crush the shells, allowing hard parts to be ejected and soft parts digested. While the hard-shelled prey items are the most common food for the pumpkinseed, bottom dwelling insect larvae like dragonflies and midges are preferred and become more important in the summer when they are abundant.

Pumpkinseeds reach maturity by their second or third year and spawn between April and June, when temperatures reach 13-17°C. Males construct nest depressions in colonies to protect their young from outside predators but each individual male will also strictly defend his nest from other males in the colony. Large males control the preferred mating sites, usually in sand or gravel, less than 1 m deep, and filled with copious woody debris. Males guard embryos until they hatch but it is believed that there are multiple mating strategies for males that may relieve some of this duty (see bluegill page for potential scenario). Females will lay 600-7,000 eggs per season in multiple males’ nests, the number increasing with female age and size. When the eggs hatch 3-5 days later the pumpkinseed offspring make their way into open water where they will feed on plankton before settling into a bed of aquatic vegetation another several weeks later. In an area where bluegills dominate the vegetation beds, pumpkinseed young will move into the food rich but heavily predated open water. Those that survive will have grown at a superior rate as compared to juveniles that fed only in aquatic plant beds but the size of open water populations is greatly reduced. On average however, pumpkinseeds will grow to 25 mm in one year, and reach 132 mm in 4 years. Some pumpkinseeds can live as long as 12 years but even at this age they rarely exceed 30 cm in length.

Links to Other Research
Watershed

Rainbow Trout and/or Steelhead Trout

Scientific Name
Oncorhynchus mykiss
Native
Native Species
Identification

Rainbow trout, 18 cm (7”) long. Location: Deer Creek, California (Yuba River basin). Date: 6/21/2007.
Rainbow trout, 18 cm (7”) long. Location: Deer Creek, California (Yuba River basin). Date: 6/21/2007.

Steelhead. Caught and released in the South Fork Mokelumne River, San Joaquin County, CA, 18 Oct 2013. Photo by Gary Riddle.
Steelhead. Caught and released in the South Fork Mokelumne River, San Joaquin County, CA, 18 Oct 2013. Photo by Gary Riddle.

Steelhead in a Santa Monica Bay coastal stream, southern California, in February 2009. Photo by Steve Williams, The Resource Conservation District of the Santa Monica Mountains. California Department of Fish and Game provided funding for the study.
Steelhead in a Santa Monica Bay coastal stream, southern California, in February 2009. Photo by Steve Williams, The Resource Conservation District of the Santa Monica Mountains. California Department of Fish and Game provided funding for the study.

Steelhead. Location: A river in Alaska. Photo courtesy of Steve Tjosvold, UC Cooperative Extension.
Steelhead. Location: A river in Alaska. Photo courtesy of Steve Tjosvold, UC Cooperative Extension.

Rainbow trout (McCloud River redband), photographed at Trout Creek, California in October 2006. Photo by Michael Carl.
Rainbow trout (McCloud River redband), photographed at Trout Creek, California in October 2006. Photo by Michael Carl.

Rainbow trout (Warner Lakes redband), photographed at Mud Creek, Oregon in July 2009. Photo by Michael Carl.
Rainbow trout (Warner Lakes redband), photographed at Mud Creek, Oregon in July 2009. Photo by Michael Carl.

Rainbow trout fry, redband sub-species.  Date: 7/10/2007.
Rainbow trout fry, redband sub-species. Date: 7/10/2007.

Rainbow trout, frontal view. Location: Deer Creek, California (Yuba River basin). Date: 6/22/2007.
Rainbow trout, frontal view. Location: Deer Creek, California (Yuba River basin). Date: 6/22/2007.

Rainbow trout, head. Date: 7/10/2007.
Rainbow trout, head. Date: 7/10/2007.

Rainbow trout, tail. Date: 7/10/2007.
Rainbow trout, tail. Date: 7/10/2007.

 

  • Commonly 35-65 cm FL and 1.4-5.4 kg; largest in CA, 12.4 kg steelhead
  • Large mouth with teeth on both upper and lower jaws
  • Silvery body, black spots on the adipose, dorsal, and caudal fins, pink to red lateral band
  • Juvenile fish have similar appearance, possess 5-13 dark spots called parr marks that run laterally along fish’s body, parr marks are smaller than the gaps between them
  • Young fish also have 5-10 dark dorsal spots between the head and dorsal fin
  • Steelhead usually lighter in color than resident rainbow trout
  • Fin rays: dorsal 10-12, anal 8-12, pelvic 9-10, pectoral 11-17
Life History

Rainbow trout are by definition a cold water fish. Optimal growth occurs at 15-18ºC and mortality typically results at 24-27ºC. New research is revealing populations of trout that are sustaining life in conditions previously considered lethal. Trout or steelhead require near saturation levels of dissolved oxygen to grow, though these fish can live at levels as low as 1.5-2.0 mg/L. Oncorhynchus mykiss generally have one of two distinct life patterns: resident inland trout and sea-run or anadromous steelhead. Some inland trout do migrate for the purpose of spawning or food foraging. Resident forms of O. mykiss often spend their entire lives within a few hundred meters of stream or within the same lake. Steelhead or sea-run trout hatch in freshwater and then migrate to the ocean, finally returning home to spawn. Times spent in freshwater and in the ocean vary according to geography, life history patterns, and effects of natural phenomena. Spawning occurs in places where the streambed is composed of gravelly substrate, usually in riffles or pool tails. The female fish digs a redd (nest) and deposits 200 to 12,000 eggs depending upon her body size. Resident rainbow trout usually produce less than 1,000 eggs per year while steelhead may produce up to 2,000 eggs per kg of body weight. After breeding the resident trout disperse to slower waters and the steelhead rest before moving back out to sea. In 3-4 weeks the eggs hatch and the young trout spend another 2-3 weeks under the cover of the gravel before emerging as fry. In some instances the fry of anadromous steelhead will emerge soon after hatching and swim straight to the ocean to avoid dry summer periods. Typically the young steelhead or parr reside in freshwater for 1-3 years before smoltification (transition to being able live in salt water). When the smolts finally reach the ocean they begin feeding on estuarine invertebrates, krill, and then focus on fish. Steelhead may stay in saltwater for 1-2 years before returning to their native streams. Most anadromous salmonids die after spawning but steelhead may make numerous trips back and forth between fresh and salt water to breed. Steelhead may spawn up to four times per life span, though the mortality rate between successive cycles is high. Rainbow trout do not commonly live beyond 6 years, though fish have been recorded to reach 9-11 years. Within a stream resident rainbows and freshwater phase steelhead have in-stream habitat preferences generally determined by size. The smallest fish are mostly found in riffles, medium sized fish in runs, and larger fish predominantly in pools. In streams and lakes rainbow trout feed on zooplankton, invertebrates, insects, drifting organisms, and sometimes other fish. Feeding usually peaks at dawn and dusk and summer consumption is greater than that in winter.

See the Golden Trout page for information about California's state fish. Golden trout are three subspecies of rainbow trout.

Video of rainbow trout:

<img src="//ucanr.edu/media/sb379612.png" alt="Image from Flash Video" />
Rainbow trout in Cow Creek, 7 June 2005. Videography by Richard Enos. Edited by Lisa Thompson, with permission. Some of this video footage was originally shown in the KVIE documentary "Sacramento: River of Life", produced by Craig Miller.

Links to Other Research

Wild Eagle Lake Rainbow Trout Restoration Project. 

Video of collaborative research project conducted by UC Cooperative Extension, UC Davis, California Department of Fish and Game, US Forest Service, Pine Creek Coordinated Resource Management Planning Group, Susanville Indian Rancheria, and many volunteers. Produced and directed by Dave Giordano, Ecosite Media. Running time: 5 minutes 15 seconds.

<img src="//ucanr.edu/media/sb379669.png" alt="Image from Flash Video" />
Wild Eagle Lake Rainbow Trout Restoration Project

Steelhead Distribution and Habitat Use in the Salinas River Watershed

Effects of Pulsed Flows from Dams on Fishes: Field and Lab Studies

Restoration of Wild Eagle Lake Rainbow Trout

Rainbow Trout Distribution and Habitat Use in Rangeland Streams

Conservation of Shasta River Coho Salmon (see reports for rainbow trout distribution)

Watershed
  • Alisal-Elkhorn Sloughs Watershed
  • Aliso-San Onofre Watershed
  • Antelope-Fremont Valleys Watershed
  • Applegate Watershed
  • Big-Navarro-Garcia Watershed
  • Bodega Bay Watershed
  • Butte Watershed
  • Calleguas Watershed
  • Carmel Watershed
  • Central Coastal Watershed
  • Chetco Watershed
  • Cottonwood Headwaters Watershed
  • Cottonwood Tijuana Watershed
  • Coyote Watershed
  • Cuyama Watershed
  • East Branch North Fork Feather Watershed
  • Estrella Watershed
  • Goose Lake Watershed
  • Honcut Headwaters Watershed
  • Honey-Eagle Lakes Watershed
  • Illinois Watershed
  • Lake Tahoe Watershed
  • Los Angeles Watershed
  • Lost Watershed
  • Lower American Watershed
  • Lower Bear Watershed
  • Lower Butte
  • Lower Cache Watershed
  • Lower Calaveras-Mormon Slough Watershed
  • Lower Cosumnes-Lower Mokelumne Watershed
  • Lower Cottonwood Watershed
  • Lower Eel Watershed
  • Lower Feather Watershed
  • Lower Klamath Watershed
  • Lower Pit Watershed
  • Lower Sacramento Watershed
  • Lower Yuba Watershed
  • Mad-Redwood Watershed
  • Madeline Plains Watershed
  • Mattole Watershed
  • McCloud Watershed
  • Middle Fork Eel Watershed
  • Middle Fork Feather Watershed
  • Middle Kern-Upper Tehachapi-Grapevine Watershed
  • Middle San Joaquin-Lower Chowchilla Watershed
  • Middle San Joaquin-Lower Merced-Lower Stanislaus Watershed
  • Mill Watershed
  • Mill-Big Chico Watershed
  • Mojave Watershed
  • Newport Bay Watershed
  • North Fork American Watershed
  • North Fork Feather Watershed
  • Owens Lake Watershed
  • Pajaro Watershed
  • Panoche-San Luis Reservoir Watershed
  • Russian Watershed
  • Sacramento Headwaters Watershed
  • Sacramento-Lower Cow-Lower Clear Watershed
  • Sacramento-Lower Thomes Watershed
  • Sacramento-Stone Corral Watershed
  • Sacramento-Upper Clear Watershed
  • Salinas Watershed
  • Salmon Watershed
  • San Antonio Watershed
  • San Diego Watershed
  • San Francisco Bay Watershed
  • San Francisco Coastal South Watershed
  • San Gabriel Watershed
  • San Jacinto Watershed
  • San Joaquin Delta Watershed
  • San Lorenzo-Soquel Watershed
  • San Luis Rey-Escondido Watershed
  • San Pablo Bay Watershed
  • Santa Ana Watershed
  • Santa Barbara Coastal Watershed
  • Santa Clara Watershed
  • Santa Margarita Watershed
  • Santa Maria Watershed
  • Santa Monica Bay Watershed
  • Santa Ynez Watershed
  • Scott Watershed
  • Seal Beach Watershed
  • Shasta Watershed
  • Smith Watershed
  • Smoke Creek Desert Watershed
  • South Fork American Watershed
  • South Fork Eel Watershed
  • South Fork Kern Watershed
  • South Fork Trinity Watershed
  • Suisun Bay Watershed
  • Surprise Valley Watershed
  • Tomales-Drake Bays Watershed
  • Trinity Watershed
  • Truckee Watershed
  • Tulare-Buena Vista Lakes Watershed
  • Upper Bear Watershed
  • Upper Butte
  • Upper Cache Watershed
  • Upper Calaveras Watershed
  • Upper Chowchilla-Upper Fresno Watershed
  • Upper Coon-Upper Auburn Watershed
  • Upper Cosumnes Watershed
  • Upper Cow-Battle Watershed
  • Upper Deer-Upper White Watershed
  • Upper Dry Watershed
  • Upper Eel Watershed
  • Upper Elder-Upper Thomes Watershed
  • Upper Kaweah Watershed
  • Upper Kern Watershed
  • Upper King Watershed
  • Upper Klamath Watershed
  • Upper Los Gatos-Avenal Watershed
  • Upper Merced Watershed
  • Upper Mokelumne Watershed
  • Upper Pit Watershed
  • Upper Poso Watershed
  • Upper Putah Watershed
  • Upper San Joaquin Watershed
  • Upper Stanislaus Watershed
  • Upper Stony Watershed
  • Upper Tule Watershed
  • Upper Tuolumne Watershed
  • Upper Yuba Watershed
  • Ventura Watershed
  • Warner Lakes Watershed

Rainwater Killifish

Scientific Name
Lucania parva
Native
Non-Native
Identification

missing fish photo

  • Chunky body
  • Rounded dorsal and caudal fins
  • Oblique mouth with single row of teeth
  • Olive colored on the back with silvery-blue sides and yellow bellies
  • 9-14 dorsal, 8-13 anal, 12-18 caudal, 10-15 pectoral, and 4-7 pelvic fin rays
  • Males have black on the anterior dorsal fin rays and the edges of the dorsal and anal fins and acquire orange fins and a crosshatch pattern when mating
  • Females have a pouch covering the posterior of the anal fin
  • 23-29 scales on the lateral line
  • Large eyes
Life History

 

Rainwater killifish are usually found in brackish water and are able to withstand salinities anywhere between 0 ppt and 80 ppt. In California this is most often tidal ditches, channelized ends of inflowing streams, ponds in diked areas, and in streams with unshaded silt bottom pools. They can also be found in shallow salt evaporation ponds with high salinities and dissolved oxygen levels between 2 and 3 mg/L. In most cases this leaves only western mosquitofish and threespine sticklebacks as companions. Rainwater killifish will feed on whatever invertebrates are available with younger individuals feeding most commonly on mosquito larvae. As they get larger their diet can diversify making copepods, brine shrimp, and amphipods more common prey items.

Rainwater killifish can survive in high salinity waters but reproduction is best conducted in salinities below 18 ppt, so while it has not been observed in California, large scale migrations into freshwater are common in the killifish's native distribution. It is known that the California mating season is between May and July when temperatures are between 17°C and 25°C. Males establish territories above aquatic vegetation beds by fiercely displaying to other males and circling females when they pass through. If a female stops the male will swim underneath her and push up towards the surface. Here they wrap around each other before dropping their fertilized eggs to stick on the vegetation below. This is often a small amount compared to other fish species and females will only lay 10-100 eggs a season. These eggs hatch in about 12 days when temperatures are approximately 24-25°C. The larvae settle to the bottom to feed off their yolk sac for about a week after hatching before joining free-swimming schools under cover of vegetation or in the very shallow water where predation is limited. They will mature in 3-5 months at sizes as small as 25 mm.

Links to Other Research
Watershed

Razorback Sucker

Scientific Name
Xyrauchen texanus
Native
Native Species
Identification

Razorback sucker. Photo taken at the Ouray National Fish Hatchery by Mark Fuller, a biologist for the US Fish and Wildlife Service, and provided by Tim Modde, USFWS.
Razorback sucker. Photo taken at the Ouray National Fish Hatchery by Mark Fuller, a biologist for the US Fish and Wildlife Service, and provided by Tim Modde, USFWS.

  • Sucker body, rarely exceed 50 cm SL, max 76 cm SL (5-6 kg)
  • Presence of bulging fontanel and sharp keel anterior to dorsal fin
  • Sub-terminal mouth: few papillae, lower lip with deep medial notch,
  • Olive to dusky back, brownish sides, yellow-orange to white underside
  • Spawning males: bright yellow underside, orange side bands, breeding tubercles on pelvic, anal, and caudal fins
  • Spawning females: similar coloration, less developed tubercles may be present
  • Fin rays: dorsal 13-16, anal 7
  • Lateral line scales: 68-87
Life History

Razorback suckers are listed as an endangered species and in California fail to have any remaining naturally propagating populations. Razorback suckers primarily inhabit large slow moving sections of river within the Colorado River drainage, though they also inhabit scattered lakes and basins. They are found in deep pools, oxbow lakes, and backwaters within a stream and may also move into reservoirs or gravel pits. During high flows the suckers have the keel and hump (acting like a spoiler) to help them resist being pulled downstream. Razorback suckers are usually found above mud and sand and may have historically moved into the floodplain. Juvenile suckers tend to live in shallow water such as man-made canals and ditches. Larval suckers feed on detritus, diatoms and algae. As they grow they begin to consume rotifers and planktonic crustaceans. Eventually as they become more bottom oriented they feed on chironomid larvae and small insects. Adult suckers tend to swim in small schools and feed on the bottom of a stream. In lakes the suckers move into deeper water and feed on detritus, algae, zooplankton, and aquatic insect larvae. Razorback suckers grow at an average rate of 7-8 mm per year for about the first 5 years of life, at which time they reach sexual maturity. Under optimal conditions they may reach 40 cm TL in their first year. In the 1980s and 1990s razorback suckers in the lower Colorado River were aged at 24-45 years old. Sexually mature males form loose shoals in spawning sites and await the females in November or December. Once the females arrive, the fish spawn for the next two months. Each female is surrounded by two or more males. The female and male fish release eggs and milt simultaneously. Female suckers spawn repeatedly until they release a total of 36,000 to 140,000 eggs. The eggs stick to the substrate for the 1-2 week incubation period. The emergent larvae consume a yolk sac for another 7-12 days before drifting downstream. The larvae may thrive in isolated ponds or backwaters, but are often eaten when in the presence of alien predators.

Links to Other Research
Watershed
  • Havasu-Mohave Lakes Watershed
  • Imperial Reservoir Watershed
  • Lower Colorado Watershed
  • Piute Wash Watershed

Red Shiner

Scientific Name
Cyprinella lutrensis
Native
Non-Native
Identification

Red shiner. Caught in the Rock River, Rock County, Minnesota, in July 2002. Photo by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.
Red shiner. Caught in the Rock River, Rock County, Minnesota, in July 2002. Photo by Konrad Schmidt, Nongame Fish Biologist, Division of Ecological Services, Minnesota Department of Natural Resources.

 

  • Deep, compressed body with a terminal mouth
  • Breeding males have tubercles on their head, sides, and fins
  • Buff to steely blue on back with silver on the sides and white on the belly
  • Breeding males have red to orange caudal, anal, pelvic, and pectoral fins, steely blue sides, heads that are red on top and pinkish on the side, and purplish crescents behind the opercles
  • 8 dorsal, 8-9 anal, 13-15 pectoral, and 8 pelvic fin rays
  • 33-36 scales on a lateral line that curves down from the head
Life History

Red shiners are adapted to, and most frequently found in, unstable environments that other species may have difficulty surviving in. This includes intermittent streams and highly disturbed, polluted areas like drainage ditches and certain reservoirs. They are capable of surviving in pHs from 4-11, salinities as high as 10ppt, dissolved oxygen levels as low as 1.5 mg/L, and temperatures as high as 39.5°C. They can also withstand rapid temperature shifts as dramatic as 21°C. In California there are two major populations with different habitat preferences. In the San Joaquin Valley turbid, alkaline, shallow, and slow moving streams are the preferred red shiner habitat. In contrast, the Colorado River finds the majority of its red shiners in backwaters and sloughs avoiding high currents. Overall, areas of silt and other fine substrates, less than 30 cm deep, with velocities between 10 and 50 cm/sec and vegetative cover are the most common locations for the species. Red shiners swim in large schools during the day individually picking off whatever is prey is most abundant. This commonly means a diet high in small crustaceans, aquatic insect larvae, and surface insects but can also include larval fish when they are available and algae when other resources are limited.

Red shiners are mature by their second summer and mate when temperatures are between 15°C and 30°C. In California this can make for a fairly long season, potentially May through October. Spawning occurs in slow moving water in both a territorial and group fashion. Non-territorial males will begin by chasing after a female in the school, often jumping out of the water as they go. After a meter or so, the two will settle down and begin swimming next to each other using the male’s tubercles to stay connected. Being fractional spawners, fecundity can vary but unspawned females have been found to hold 485-1,200 eggs. When laid, these eggs stick to plants, gravel, roots, logs, and other submerged debris but little is known about red shiners early life history beyond this. However, it is known that they will grow to between 25 mm and 30 mm by their first summer and grow another 5-15 mm over the next year reaching a maximum of 80 mm in 2.5 to 3 years.

Links to Other Research
Watershed

Redbelly Tilapia

Scientific Name
Tilapia zillii
Native
Non-Native
Identification

Redbelly tilapia, spawning colors. Location: Arthur 0.5 Drain, Salton Sea. Date: Oct. 28, 2010. Photo by Sharon Keeney, California Department of Fish and Game.
Redbelly tilapia, spawning colors. Location: Arthur 0.5 Drain, Salton Sea. Date: Oct. 28, 2010. Photo by Sharon Keeney, California Department of Fish and Game.

Redbelly tilapia, non-spawning colors. Location: Arthur 0.5 Drain, Salton Sea. Date: Oct. 28, 2010. Photo by Sharon Keeney, California Department of Fish and Game.
Redbelly tilapia, non-spawning colors. Location: Arthur 0.5 Drain, Salton Sea. Date: Oct. 28, 2010. Photo by Sharon Keeney, California Department of Fish and Game.

Redbelly tilapia, spawning colors (left side). Location: Arthur 0.5 Drain, Salton Sea. Date: Oct. 28, 2010. Photo by Sharon Keeney, California Department of Fish and Game.
Redbelly tilapia, spawning colors (left side). Location: Arthur 0.5 Drain, Salton Sea. Date: Oct. 28, 2010. Photo by Sharon Keeney, California Department of Fish and Game.

Redbelly tilapia, non-spawning colors (left side). Location: Oasis-Grant Drain, Salton Sea. Date: Oct. 25, 2010. Photo by Sharon Keeney, California Department of Fish and Game.
Redbelly tilapia, non-spawning colors (left side). Location: Oasis-Grant Drain, Salton Sea. Date: Oct. 25, 2010. Photo by Sharon Keeney, California Department of Fish and Game.

  • Deep, elongate, laterally compressed body with the head wider than the rest of the body
  • Nearly horizontal mouth
  • Normally dark olive on back, light olive or brown sides, a yellow to white belly, and brown to yellow fins
  • Sides often have an iridescent sheen and 6-7 poorly defined vertical bars
  • Both the operculum and dorsal fin have a dark spot. The dorsal fin’s spot is often outlined in yellow and surrounded by smaller yellow spots
  • Spawning fish become a shiny dark green on the back and sides with a bright red throat and belly, distinct vertical bands on the side, and mottled blue-green spots over a dark blue-black head
  • 14-16 spinesand 10-13 rays in the long dorsal fin, many of the rays are longer than the spines
  • 3-4 spines and 7-10 rays in the anal fin
  • 14-15 rays in the pectoral fins
  • Rounded caudal fin
  • 28-30 cycloid scales on the lateral line
Life History

 

Redbelly tilapia are naturally found in large lakes and rivers but have successfully invaded a variety of ponds, irrigation ditches, and other artificial habitats. In California this is especially true in the warm, saline, irrigation return waters of the Imperial Valley. They have been found in salinities of 29-35 ppt and temperatures as high as 38°C. Low temperatures seem to be a restraint however as temperatures below 13°C are usually lethal and reproduction can not happen below 20°C. Aquatic plants and algae make up the majority of their diet and their teeth are designed for optimum foraging of these materials. Despite this adaptation tilapia will still eat invertebrates, often when found on aquatic vegetation, and even fish provided they are dead or dying. The young also feed substantially on crustaceans for the first few months of life.

 

Mating begins whenever waters are above 20°C, which in Southern California is about 6 months of the year. Redbelly tilapia will look for shallow, protected areas with bottoms of rock, sand, or mud, but prefer a softer substrate to dig their nests into. They breed in circular colonies with the outer fish providing a line of protection for those inside of the circle. Spawning occurs when a mating pair is formed and a nest is built into the substrate. The female will then lay her 1,000-6,000 eggs inside the nest for the male to fertilize. Both parents will care for the embryos by fanning water across the eggs to increase oxygen intake, removing debris from the nest, and blocking the entrance with their bodies as protection from predators. The embryos hatch in 2-3 days and the young are then transferred by mouth or fin fanning to a nearby depression for 3-4 days until their yolk sac is absorbed and they become free swimming. Adults can mate again in a month and can continue to do so as long as conditions are acceptable. In California this usually means between 4 and 6 broods a season. Growth for young tilapia is very dependent on the size of their population. In low densities like those found in irrigation ditches they can grow as much as 17 cm in first year but tilapia found in crowded ponds can take as long as 2 years to reach a length of only 7 cm. Redbelly tilapia normally measure 13-14 cm TL before breeding, but may mature at smaller sizes in Imperial Valley ditches and Coachella Valley ditches.

Links to Other Research
Watershed

Redear Sunfish

Scientific Name
Lepomis microlophus
Native
Non-Native
Identification

Redear sunfish (left) and bluegill (right). Photo courtesy of Professor Peter B. Moyle.
Redear sunfish (left) and bluegill (right). Photo courtesy of Professor Peter B. Moyle.

  • Deep bodied
  • Small oblique mouth
  • Long pointed pectoral fins
  • Opercular flap has an orange-red edge ahead of a dark splotch
  • Coloration:
    • Dorsal fin dusky without a dark spot near the rear
    • Adults light olive on the back, pale mottled brown to silver on the sides, often with speckling and yellow on the lower sides and belly
    • Young-of-the-year can have 7-8 vertical bars on the side (faint)
  • 10 spines and 11-12 rays in the dorsal fin
  • 3 spines and 10-11 rays in the anal fin
  • 13 rays in the pectoral fins
  • 1 spine and 5 rays in the pelvic fins
  • 34-43 scales on the lateral line
Life History


Redear sunfish are most commonly found in the deeper waters of warm, quiet ponds and lakes, or in back waters and sloughs with substantial beds of aquatic vegetation. They will avoid turbid or shallow water where increased food competition limits their reproductive ability. They can survive in salinities up to 20 ppt but in California they tend to avoid brackish water. Hard shelled invertebrates make up the majority of the redear sunfish diet, with bottom dwelling snails and clams and aquatic plants being the most common targets. This is made possible by molar-like teeth that can crush shells, allowing inedible parts to be ejected and soft parts digested. While the hard shelled prey items are the most common food for the redear sunfish this because they are so readily abundant. Bottom dwelling insect larvae like dragonflies and midges are actually preferred and become more important in the summer when they become more abundant.

Redear sunfish are estimated to reach maturity in California in approximately 3-4 years or when they have grown to between 13 cm and 18 cm in length. Spawning occurs throughout the summer when temperatures reach 21-24°C, potentially as early as mid-April in lowland areas. Males construct 25-61 cm wide nest depressions in sand, gravel, or mud 5-10 cm deep. The nests are built in colonies to protect them from outside predators but each individual male will also strictly defend his nest from other males in the colony. Most males guard the nests until the embryos hatch but it is believed that there are multiple mating strategies for male redear sunfish that may relieve some of this duty (see bluegill page for potential scenario). Females will lay 9,000-80,000 eggs per season in multiple males’ nests, the number increasing with age and size. When the eggs hatch 3-5 days later the larvae make their way into open water where they will feed on plankton before settling into a bed of aquatic vegetation several weeks later.

Growth can be quite variable, with a small turbid lake producing fish 48 mm long in their first year and 163 mm in their fourth, while a larger, clearer lake may produce fish 69 mm their first year and 170 mm in their fourth. However, growth rates in these large lake populations can level off near 200 mm, while fish in smaller lakes will see continued growth, resulting in 5-6 year olds that average 254 mm. The largest recorded redear sunfish was 2.4 kg and the oldest was 7 years old.

Links to Other Research
Watershed

Redeye Bass

Scientific Name
Micropterus coosae
Native
Non-Native
Identification

Redeye bass, adult. Caught in eastern USA. Photo courtesy of Drew Gregory.
Redeye bass, adult. Caught in eastern USA. Photo courtesy of Drew Gregory.

Redeye bass, juvenile. Photo courtesy of Drew Gregory.
Redeye bass, juvenile. Photo courtesy of Drew Gregory.

Juvenile basses. Photos courtesy of Patrick Crain and Scott Matern.
Juvenile basses. Photos courtesy of Patrick Crain and Scott Matern.

  • Brightly colored with a purplish or greenish cast to the sides, and a distinct white band on the upper and lower edges of the caudal fin
  • Reddish eyes (but several other bass species, including smallmouth bass and spotted bass, may also have red eyes)
  • Rows of dark spots on the lower sides and there may be a row of diamond shaped bars along the midline
  • Strongly patterned with irregular blotching along the back
  • Upper jaw extends to the middle of the eye
  • 9-11 dorsal and 3 anal spines
  • 11-13 dorsal, 9-11 anal, and 14-17 pectoral fin rays
  • 64-73 scales on the lateral line
  • Scales on cheek are arranged in 14 rows and are smaller than the opercular scales
  • Scales are usually present on the base of the dorsal and anal fin
  • Young have distinct vertical bands on their sides that extend below the lateral line and rusty red base of the caudal fin
  • Second dorsal, caudal, and front of anal fin brick red on young
Life History

Redeye bass are most common in small, clear, upland streams with pools, pockets of water near boulders and undercut banks, and summer temperatures near 26-28°C. They are also rarely found in reservoirs. Redeye bass are opportunistic predators, hunting at the surface, in the water column, and off the bottom. Terrestrial insects make up the majority of their diet, but aquatic insects, fish, crayfish, and salamanders are also common prey items. Redeye bass can make these captures by either ambush or from just cruising around their home area, both methods utilizing a rapid burst of speed that catches the prey off guard. This predator is so skilled that even before reaching adulthood, relatively small redeye bass are capable of eating small mosquitofish.

Maturity is reached when the individual is 12-13 cm long, usually between 2 and 4 years of age. In late spring, when temperatures reach 17-21°C, these adults move up small tributary streams to construct nests. It is believed that mating is similar to that of smallmouth bass, where spawning is initiated by a female repeatedly swimming by a male’s nest, changing colors, and keeping her head down in a mating posture. Eventually the pair circle the nest with the male nipping at the female, and the female occasionally rubbing her abdomen on the nest floor. The pair will then settle into the nest and release their eggs and milt simultaneously. While this behavior has yet to be accurately recorded, we do know that redeye bass have fecundities that vary with size, and that females at 15 cm TL average 2,084 eggs per season. These eggs will produce juveniles that grow to 4.5-6.5 cm TL in first year, but take another 9-10 years to reach 25 cm TL. The rare populations that exist in reservoirs grow more quickly and will reach 7-8 cm in a year. Even this measure is much smaller than the growth rates in their native territories, where individuals will reach 22 cm TL by their second year. In California any redeye bass greater than 35 cm are believed to be hybrids with smallmouth bass.

Links to Other Research
Watershed

Reticulate Sculpin

Scientific Name
Cottus perplexus
Native
Native Species
Identification

missing fish photo

  • Maximum size 110 mm SL, resembles riffle sculpin and marbled sculpin
  • Dorsal fins broadly joined, narrow mouth
  • Preopercular spines: (1-4), usually (2) visible
  • Prickling variable, axillary patch present
  • Coloration: body covered with wavy lines and patches of dark pigment, checkerboard pattern on pectoral fins, dark blotch on back of 1st dorsal fin
  • Fin rays/spines: 1st dorsal 7-8 spines, 2nd dorsal 18-20 rays, pectoral 13-16 rays, anal 13-16 rays
Life History

 

Reticulate sculpins are abundant in the slow moving reaches of coastal headwater streams. In California their distribution is limited to several streams that are part of an Oregon-bound watersheds. Favorable habitat for reticulate sculpin includes riffles in small streams with water temperatures that do not exceed 20°C. Though these fish prefer rubble or gravel substrate, they will keep to stream margins and silty pools in the presence of other sculpin species. Reticulate sculpins have a tolerance for high temperatures and moderate salinities, leaving them as the sole sculpin species in streams with such conditions. They are capable of living in water conditions that include temperatures of 30°C and salinities of 18 ppt. The diet of reticulate sculpins is made up of mostly aquatic invertebrates such as mayflies, stoneflies, beetles, caddisflies, and chironomid midges. They reach sexual maturity early in life but fail to reach large sizes. On average a 4 year old fish might only measure 64 mm SL. Reticulate sculpin spawn in March through May when water temperatures have reached a suitable range of 6-7°C. Male sculpins create nests in gravel or cobble substrate where several females may deposit 35-315 eggs each. Nests are created in swiftwater reaches where other species of sculpins are absent and in slow flowing water when competitors are present. Male sculpins guard the nests and the larval fish until the fry are capable of surviving alone. Young sculpin spend the early part of their life swimming along the bottom in slow water.

 

Links to Other Research
Watershed
  • Applegate Watershed

Riffle Sculpin

Scientific Name
Cottus gulosus
Native
Native Species
Identification

Riffle sculpin, side view. Location: South Fork American River. Date: 5 May 2010. Photo by Lisa C. Thompson.
Riffle sculpin, side view. Location: South Fork American River. Date: 5 May 2010. Photo by Lisa C. Thompson.

Riffle sculpin, ventral view. Location: South Fork American River. Date: 5 May 2010. Photo by Lisa C. Thompson.
Riffle sculpin, ventral view. Location: South Fork American River. Date: 5 May 2010. Photo by Lisa C. Thompson.

Riffle sculpin, frontal view. Location: South Fork American River. Date: 5 May 2010. Photo by Lisa C. Thompson.
Riffle sculpin, frontal view. Location: South Fork American River. Date: 5 May 2010. Photo by Lisa C. Thompson.

  • Adults up to 100 mm SL, larger sizes rare
  • Large mouth, maxillary may reach rear margin of eye
  • Prickles behind pectoral fins
  • Pre-opercular spines: 2-3
  • One median chin pore
  • Joined dorsal fins (usually)
  • Mottled coloration, black spot on rear side of 1st dorsal fin
  • Spawning males dark, may have orange edge of 1st dorsal
  • Fin spines/rays: pelvic 1 spine/3-4 rays, 1st dorsal 7-8 spines, 2nd dorsal 16-19 rays, pectoral 15-16 rays, anal 12-16 rays
  • Pelvic fin "elements": 4 (1 spine, 3-4 rays, but the spine may be fused with the 1st ray)
  • Lateral line: complete or incomplete, 22-36 pores
Life History

Riffle sculpins are found in headwater streams with cold water and rocky or gravelly substrate. They prefer permanent streams where the water does not exceed 25-26°C, and where ample flow keeps the dissolved oxygen level near saturation. Riffle sculpins may occupy riffles or pools, though they tend to favor areas that have adequate cover in the form of rocks, logs, or overhanging banks. These fish have similar habitat requirements similar to those of rainbow trout and are often found in association with them. Riffle sculpins are opportunistic feeders that may pursue prey by night or ambush during the day. The diet of a sculpin may include amphipods, benthic invertebrates, fish, and various stages of caddisflies and mayflies. Riffle sculpins reach sexual maturity in the end of their second year, with spawning taking place in late winter to early spring. Females lay 462-1,000 or more eggs under rocks within swiftwater reaches of a stream. The male takes the responsibility of guarding the nest which may contain the eggs of multiple females. Riffle sculpins rarely exceed 4 years of life.

Links to Other Research
Watershed
  • Alisal-Elkhorn Sloughs Watershed
  • Bodega Bay Watershed
  • Coyote Watershed
  • East Branch North Fork Feather Watershed
  • Gualala-Salmon Watershed
  • Honcut Headwaters Watershed
  • Lower American Watershed
  • Lower Bear Watershed
  • Lower Butte
  • Lower Cache Watershed
  • Lower Cosumnes-Lower Mokelumne Watershed
  • Lower Cottonwood Watershed
  • Lower Feather Watershed
  • Lower Pit Watershed
  • Lower Sacramento Watershed
  • Lower Yuba Watershed
  • McCloud Watershed
  • Middle Fork Feather Watershed
  • Middle San Joaquin-Lower Chowchilla Watershed
  • Middle San Joaquin-Lower Merced-Lower Stanislaus Watershed
  • Mill Watershed
  • North Fork American Watershed
  • North Fork Feather Watershed
  • Pajaro Watershed
  • Russian Watershed
  • Sacramento Headwaters Watershed
  • Sacramento-Lower Cow-Lower Clear Watershed
  • Sacramento-Lower Thomes Watershed
  • Sacramento-Stone Corral Watershed
  • Sacramento-Upper Clear Watershed
  • Salinas Watershed
  • Salmon Watershed
  • San Francisco Bay Watershed
  • San Pablo Bay Watershed
  • South Fork American Watershed
  • Suisun Bay Watershed
  • Tomales-Drake Bays Watershed
  • Upper Bear Watershed
  • Upper Butte
  • Upper Cache Watershed
  • Upper Calaveras Watershed
  • Upper Coon-Upper Auburn Watershed
  • Upper Cosumnes Watershed
  • Upper Cow-Battle Watershed
  • Upper Kaweah Watershed
  • Upper King Watershed
  • Upper Merced Watershed
  • Upper Mokelumne Watershed
  • Upper Putah Watershed
  • Upper San Joaquin Watershed
  • Upper Stanislaus Watershed
  • Upper Tuolumne Watershed
  • Upper Yuba Watershed

River Lamprey

Scientific Name
Lampetra ayresi
Native
Native Species
Identification

River lamprey, captured in rotary screw trap on Sacramento River at Knight's Landing. Photo by Dan Worth, California Department of Fish and Game.
River lamprey, captured in rotary screw trap on Sacramento River at Knight's Landing. Photo by Dan Worth, California Department of Fish and Game.

  • Small lamprey, average spawning adult: 17 cm TL
  • Large eyes: diameter of eye 1-1.5 x distance between rear edge of eye and first branchial opening
  • Body segments (myomeres): adults 68, ammocoetes 67 (65-70)
  • Sexually mature adults: 2 dorsal fins grow into 1 dorsal fin
  • Adult coloration: dark back and sides, silver to yellow belly, heavily pigmented tail
  • Ammocoetes coloration: lightly pigmented tail, pale head, line behind eye spot
  • Oral disc is as wide or wider than head, horny plates or teeth well developed
  • Transverse lingual lamina (tongue plate): middle cusp well developed
  • Infraoral plate: 7-10 cusps
  • Supraoral plate: 2 cusps
  • Circumoral plates: 3 on each side (bicuspid-tricuspid-bicuspid)
Life History

 

The life history of river lampreys is not fully understood and any studies were documented in British Columbia where the life pattern and timing of events might differ from California and the southern reaches of distribution.

River lampreys are anadromous and they live a predaceous life when in the ocean. Larval lampreys or ammocoetes probably spend the first 3-5 years within a freshwater stream. Ammocoetes burrow themselves tail-first into the soft substrate of a backwater where they feed on drifting matter such as algae and microorganisms. When the ammocoetes reach around 12 cm TL and several years of age they begin to transform into adults during the summer. Metamorphosis takes 9-10 months, which is the longest transition of all the lampreys. Before river lampreys have completed the change they assemble at the mouth of the river, finally entering the ocean in late spring. River lampreys are believed to spend only 3-4 months at sea where they grow rapidly by attaching to fish such as salmon and herring and feeding on muscle tissue. The voracious lampreys may kill the prey though feeding continues even after death. In the fall of the same year the river lampreys return to their natal streams and spawn from February to May. During the last part of their life the lampreys actually shrink up to 20% in length. Spawners dig nests or depressions in gravel where a female lays her eggs. Fecundity is not well recorded, but egg production was estimated in one stream to be 11,400-37,300 eggs per female.

Links to Other Research
Watershed
  • Big-Navarro-Garcia Watershed
  • Bodega Bay Watershed
  • Chetco Watershed
  • Coyote Watershed
  • Gualala-Salmon Watershed
  • Lower American Watershed
  • Lower Butte
  • Lower Cache Watershed
  • Lower Cosumnes-Lower Mokelumne Watershed
  • Lower Eel Watershed
  • Lower Feather Watershed
  • Lower Klamath Watershed
  • Lower Sacramento Watershed
  • Mad-Redwood Watershed
  • Mattole Watershed
  • Middle Fork Eel Watershed
  • Russian Watershed
  • Sacramento-Lower Thomes Watershed
  • Sacramento-Stone Corral Watershed
  • Salmon Watershed
  • San Francisco Bay Watershed
  • San Joaquin Delta Watershed
  • San Pablo Bay Watershed
  • Smith Watershed
  • South Fork Eel Watershed
  • Suisun Bay Watershed
  • Tomales-Drake Bays Watershed
  • Trinity Watershed
  • Upper Eel Watershed

Rough Sculpin

Scientific Name
Cottus asperrimus
Native
Native Species
Identification

missing fish photo

  • Small and slim, maximum 81 mm SL
  • Body covered with prickles, giving “rough” feel
  • Light to purplish brown, dusky sides with 4-5 blotches, speckled underside
  • Dorsal fin brown to red with streaks
  • Fin spines/rays: pelvic 1 spine/3 rays, 1st dorsal 5-7 spines, 2nd dorsal 17-19 rays, anal 13-17 rays, pectoral 14-16 rays
  • Pelvic fin "elements": 3 (1 spine, 3 rays, but the spine is fused with the 1st ray)
  • Lateral line (incomplete): doesn’t extend past posterior margin of 2nd dorsal, 19-29 pores

 

Life History

Rough sculpins are primarily found in clear, cool, fast water. They live in spring-fed streams where water temperatures rarely exceed 15°C and occupy areas with aquatic vegetation and a sand or gravel substrate. While rough sculpins have shown a preference for cool water, they are capable of surviving in lakes or reservoirs where surface water temperatures reach 30°C. They are commonly found in association with marbled sculpins, rainbow trout, Sacramento suckers, tui chubs, and Pit-Klamath brook lampreys. Feeding occurs during both day and night, with peaks at dawn and dusk. Prey such as amphipods and isopods are captured at night, and are generally larger and more active than daytime prey. Throughout the year rough sculpins feed on chironomid and baetid mayfly larvae, though they tend to avoid snails and stonefly larvae. The diversity in a sculpins diet increases with body size. Rough sculpins grow slower than other sculpin species. Both sexes grow at a similar rate, though male sculpins reach larger maximum sizes. They reach sexual maturity in around 2 years and when they are bigger than 35 mm SL. The time of spawning varies between streams, with some populations spawning in fall to winter, and others spawning in winter through spring. Males find a secure nest site in various kind of habitat, where they try to entice females to spawn. Egg production is size dependent, with most females producing 140-580 large eggs. One male might have 800 to 3,000 eggs in a nest which he guards for several weeks till the larvae hatch. The newly emerged larvae remain close to the nest while developing.

Links to Other Research
Watershed
  • Lower Pit Watershed

Sacramento Blackfish

Scientific Name
Orthodon microlepidotus
Native
Native Species
Identification

Sacramento blackfish, caught in the San Joaquin river near Stockton on 11/11/08. Photo by Steve Reem.
Sacramento blackfish, caught in the San Joaquin river near Stockton on 11/11/08. Photo by Steve Reem.

 

  • Size rarely exceeds 50 cm SL and 1.5 kg, male/female growth may differ
  • Round elongated body, long narrow caudal peduncle, tiny scales: (90-105) laterally
  • Cone shaped head with flat sloping forehead, small eyes
  • Terminal mouth with thin lips, slightly upturned
  • Dorsal fin origin in front of pelvic fin origin
  • Adults light to dark gray, with olive sheen, progressively darker with size
  • Young fish silver in color
  • Males may grow breeding tubercles and develop darker coloration during breeding season
  • Fin rays: dorsal 9-11, anal 9-11, pelvic 10
Life History

 

Sacramento blackfish are native to the Sacramento and San Joaquin drainages as well as to Clear Lake. These fish however are found in other various streams and reservoirs in California, and have extended into parts of Nevada. Sacramento blackfish prefer warm turbid waters in small to large streams, and often share habitat with an array of non-natives. Sacramento blackfish prefer water temperatures in the range of 22-28°C. They have shown a great ability to adapt to extreme environments including water temperatures exceeding 30°C and salinities in excess of 9 ppt. Blackfish are typically suspension feeders with a diet of planktonic algae and zooplankton, including copepods, insect larvae, rotifers, cladocerans, and detritus. Young fish tend to feed in the water column or stream bottom on zooplankton and insects. Juvenile fish may school along lake shores where prey is abundant. As Sacramento blackfish grow they become increasingly reliant upon pumping suspended material into their mouths, using their gill rakers as a filter, and trapping food in mucous in the roof of their mouth. Adults can live on a diet of primarily organic matter and algae. Pond and lake inhabitants can feed on diatoms, algae, and zooplankton, or may pick up organic matter and small invertebrates from the bottom. Sacramento blackfish may become sexually mature in their first, second, third, or fourth years, depending upon their growth rate. Males tend to reach sexual maturity before the females, and the production of eggs in females seems to be directly related to body size. A female of 171 mm FL may produce 14,700 eggs, while a female of 466 mm FL can produce some 346,500 eggs. Spawning generally occurs in spring but may happen anytime between March and July when water temperatures are in the range of 12-24°C. Spawning beds are usually found in areas of thick vegetation and shallow water. The eggs will cling to the local substrate till the larvae emerge and begin foraging in the same region.

Links to Other Research
Watershed
  • Alisal-Elkhorn Sloughs Watershed
  • Coyote Watershed
  • Lower American Watershed
  • Lower Bear Watershed
  • Lower Butte
  • Lower Cache Watershed
  • Lower Calaveras-Mormon Slough Watershed
  • Lower Cosumnes-Lower Mokelumne Watershed
  • Lower Cottonwood Watershed
  • Lower Feather Watershed
  • Lower Pit Watershed
  • Lower Sacramento Watershed
  • Lower Yuba Watershed
  • McCloud Watershed
  • Middle Kern-Upper Tehachapi-Grapevine Watershed
  • Middle San Joaquin-Lower Chowchilla Watershed
  • Middle San Joaquin-Lower Merced-Lower Stanislaus Watershed
  • Mill Watershed
  • North Fork American Watershed
  • Pajaro Watershed
  • Panoche-San Luis Reservoir Watershed
  • Russian Watershed
  • Sacramento Headwaters Watershed
  • Sacramento-Lower Cow-Lower Clear Watershed
  • Sacramento-Lower Thomes Watershed
  • Sacramento-Stone Corral Watershed
  • Sacramento-Upper Clear Watershed
  • Salinas Watershed
  • San Francisco Bay Watershed
  • San Joaquin Delta Watershed
  • San Pablo Bay Watershed
  • South Fork American Watershed
  • Suisun Bay Watershed
  • Tulare-Buena Vista Lakes Watershed
  • Upper Bear Watershed
  • Upper Cache Watershed
  • Upper Coon-Upper Auburn Watershed
  • Upper Cosumnes Watershed
  • Upper Cow-Battle Watershed
  • Upper Deer-Upper White Watershed
  • Upper Los Gatos-Avenal Watershed
  • Upper Poso Watershed
  • Upper Putah Watershed
  • Upper Stanislaus Watershed
  • Upper Stony Watershed
  • Upper Tuolumne Watershed
  • Upper Yuba Watershed

Sacramento Perch

Scientific Name
Archoplites interruptus
Native
Native Species
Identification

Sacramento perch, juvenile (5 months old). Crowley Lake strain, reared at Contra Costa Mosquito & Vector Control District, CA.  FL = 131 mm. Photographed on 11/19/09 by Chris Miller, CCMVCD.  Note: This fish is a cannibal and grew very fast.
Sacramento perch, juvenile (5 months old). Crowley Lake strain, reared at Contra Costa Mosquito & Vector Control District, CA. FL = 131 mm. Photographed on 11/19/09 by Chris Miller, CCMVCD. Note: This fish is a cannibal and grew very fast.

Sacramento perch, adult male. Captured from Sindicich Lagoon, Martinez, California in May 2001. SL = 238 mm. Photo by Chris Miller, Contra Costa Mosquito & Vector Control District, California.
Sacramento perch, adult male. Captured from Sindicich Lagoon, Martinez, California in May 2001. SL = 238 mm. Photo by Chris Miller, Contra Costa Mosquito & Vector Control District, California.

Sacramento perch (probably a breeding male, based on dark color). Captured from Sindicich Lagoon, Martinez, CA in May 2001. SL = 221 mm. Weight = 260 g. Photo by Chris Miller, Contra Costa Mosquito & Vector Control District, CA.
Sacramento perch (probably a breeding male, based on dark color). Captured from Sindicich Lagoon, Martinez, CA in May 2001. SL = 221 mm. Weight = 260 g. Photo by Chris Miller, Contra Costa Mosquito & Vector Control District, CA.

Sacramento perch, juvenile (170 days old). Raised from wild brood fish from Sindicich Lagoon, Concord, California.  SL = 68 mm. Photographed in January 2002 by Chris Miller, Contra Costa Mosquito & Vector Control District, California.
Sacramento perch, juvenile (170 days old). Raised from wild brood fish from Sindicich Lagoon, Concord, California. SL = 68 mm. Photographed in January 2002 by Chris Miller, Contra Costa Mosquito & Vector Control District, California.

Sacramento perch, juveniles (107 days old). Raised from wild brood fish from Sindicich Lagoon, Concord, CA.  Average SL = 32 mm. Photographed in October 2002 by Chris Miller, Contra Costa Mosquito & Vector Control District, CA.
Sacramento perch, juveniles (107 days old). Raised from wild brood fish from Sindicich Lagoon, Concord, CA. Average SL = 32 mm. Photographed in October 2002 by Chris Miller, Contra Costa Mosquito & Vector Control District, CA.

  • Deep bodied (depth up to 2.5 times SL), laterally compressed, max. 61 cm TL (3.6 kg)
  • Large and oblique terminal mouth, maxilla extends to middle of eye
  • Teeth present on jaws, tongue, and roof of mouth
  • Coloration: brown sides and back with metallic green to purple sheen, white underside, 6-7 vertical bars on sides, black spot on opercula
  • Breeding males: darker than normal, opercula purple, silvery spotting
  • Breeding females: uniform coloration
  • Fin spines/rays: dorsal 12-14 spines/10-11 rays, anal 6-8 spines/10-11 rays, pectoral 13-15 rays
  • Lateral line scales (large): 38-48
Life History

Sacramento perch were historically abundant predators throughout the Central Valley of California, where they occupied sloughs, lakes, and slow moving rivers. Today they are rare in their native waters, but still exist in Clear Lake and Alameda Creek/Calaveras Reservoir, as well as in some farm ponds and reservoirs. They have been introduced through the state including the upper Klamath basin, upper Pit River watershed, Walker River watershed, Mono Lake watershed, and Owens River watershed, and may exist in Sonoma Reservoir in the Russian River watershed. Sacramento perch are most often found in warm reservoirs and ponds where summer temperature range form 18-28°C. Sacramento perch are capable of surviving high temperatures, high salinities (up to 17 ppt), high turbidity, and low water clarity. Though Sacramento perch are often found in clear water among beds of aquatic vegetation, they achieve greater numbers in turbid lakes absent of plants. Typically they are found along the bottom of inshore regions. Young-of-year perch form shoals in these areas where aquatic and overhanging vegetation provide cover. Sacramento perch are most abundant where other centrarchids are absent. They feed by stalking, and prey items vary with time, availability, and fish size. Sacramento perch are opportunistic and feeding occurs all day with peaks at dawn and dusk. Their diet is more diverse in summer than in winter. Young-of-year fish feed primarily on small crustaceans found on plants and in the substrate. Juvenile perch in Clear Lake were found to feed mostly on copepods and later cladocerans. Aquatic insect larvae and pupae become increasingly important as the fish grow. Adult fish may begin to feed on other fish, including young-of-year perch. Growth is variable and factors such as diet, overcrowding, and gender affect growth rates. Females tend to be larger than males and adult fish grow more in weight than in length. Sacramento perch reach sexual maturity in year 2 or 3 and generally spawn from March through early August when water temperatures range from 18-29°C. Prior to spawning, perch gather in shallow areas abundant with filamentous algae and macrophytes. These assembly areas may also have submerged roots, rock piles, and sticks. Male fish begin defending territories along shore where they create shallow nests. They vehemently defend their space until the arrival of a female perch, at which time they begin courting. The male and female perch release eggs and milt simultaneously, and upon completion the female perch abandons the nest. Females spawn with multiple males, producing a total of about 8,400-125,000 eggs. Egg production varies with body size. Male perch guard their nests and the embryos for several days. The emergent larvae are planktonic for a time period assumed to be about 1-2 weeks.

Links to Other Research
Watershed
  • Crowley Lake Watershed
  • East Walker Watershed
  • Honey-Eagle Lakes Watershed
  • Lost Watershed
  • Lower Sacramento Watershed
  • Mono Lake Watershed
  • North Fork Feather Watershed
  • Owens Lake Watershed
  • Panoche-San Luis Reservoir Watershed
  • Russian Watershed
  • San Francisco Bay Watershed
  • Tomales-Drake Bays Watershed
  • Upper Cache Watershed
  • Upper Klamath Watershed
  • Upper Pit Watershed
  • West Walker Watershed

Sacramento Pikeminnow

Scientific Name
Ptychocheilus grandis
Native
Native Species
Identification

Sacramento pikeminnow, juvenile. Location: Deer Creek California (Yuba River basin). Date: 6/20/2007.
Sacramento pikeminnow, juvenile. Location: Deer Creek California (Yuba River basin). Date: 6/20/2007.

Sacramento pikeminnow, adult. Photo courtesy of Dennis Cocherell, UC Davis.
Sacramento pikeminnow, adult. Photo courtesy of Dennis Cocherell, UC Davis.

Sacramento pikeminnow. Location: Feather River. Date: 19 April 2010. Photo by Lisa C. Thompson. Note the size of the mouth, which is larger than that of a hardhead.
Sacramento pikeminnow. Location: Feather River. Date: 19 April 2010. Photo by Lisa C. Thompson. Note the size of the mouth, which is larger than that of a hardhead.

Sacramento pikeminnow. Side view of mouth, showing lack of a frenum. Caught & released in the So. Fork Mokelumne R., 27 June 2012. Photo - Gary Riddle
Sacramento pikeminnow. Side view of mouth, showing lack of a frenum. Caught & released in the So. Fork Mokelumne R., 27 June 2012. Photo - Gary Riddle

Sacramento pikeminnow, head. Location: Feather River. Date: 19 April 2010. Photo by Lisa C. Thompson. Note the lack of a frenum (bridge of skin) in the groove between the snout and upper lip.
Sacramento pikeminnow, head. Location: Feather River. Date: 19 April 2010. Photo by Lisa C. Thompson. Note the lack of a frenum (bridge of skin) in the groove between the snout and upper lip.

  • Big elongated fish, may exceed 1 m TL, maximum 115 cm (14.6 kg)
  • Flattened head, large mouth, deeply forked tail
  • Bigger adults dark brown to olive in coloration, gold-yellow underside
  • Smaller fish, silver, dark spot at the base of the tail
  • Spawning fish may develop orange-reddish hue on tail, males may develop nodes or breeding tubercles on head
  • Fin rays: anal 8, dorsal 8, pectoral 15-18, pelvic 9
  • Lateral line scales: 65-78
Life History

Sacramento pikeminnows, formerly known as “squawfish”, are typically found in clear low to mid-elevation streams and rivers. Pikeminnows favor streams with deep pools and slow runs that have cover in the form of undercut banks or aquatic vegetation. While pikeminnows are often found in association with native fishes in slightly disturbed streams, they are rarely found in highly polluted rivers or sharing habitat with centrarchids in lakes. They are found where water temperatures are usually in the range of 18-28°C, though they are capable of withstanding extremes up to 38°C and salinities as high as 8 ppt. Pikeminnows grow most rapidly in the first five years of life, especially in the summer months. Fish in larger warmer waters tend to grow faster and bigger than fish found in smaller cooler waters. Younger fish feed and forage during the day, while adults tend to reside in deeper pools during the day and move into riffles to feed during dawn and dusk. Juveniles may feed on aquatic insects and change the focus of their diet to crustaceans and fish as they grow bigger. Large adults are voracious opportunistic predators and may take prey anywhere at anytime. In addition to fish, prey items may include: frogs, lamprey ammocoetes, large stoneflies, and even small rodents. At age 3-4 Sacramento pikeminnows become sexually mature and begin spawning in April – May. Ideal spawning grounds are riffles and pool tails with gravel substrate. Residents of small streams might only move to a nearby riffle whereas residents of lakes and large rivers usually move up into a small tributary stream. Male pikeminnows arrive at spawning grounds before female fish when water temperatures reach a range of 15-20°C. Spawning may occur annually or less frequently when adverse conditions exist. Females measuring 31-65 cm SL produce an average of 15,000 to 40,000 eggs each. The eggs hatch in a week or less (4-7 days) under favorable conditions. Young fish gradually spread out into small schools and move into deeper water with time, often occupying protected riffles and fast water. Pikeminnows grow and develop slowly but may reach great lengths, and ages in excess of 16 years.

Links to Other Research
Watershed
  • Alisal-Elkhorn Sloughs Watershed
  • Carmel Watershed
  • Central Coastal Watershed
  • Cottonwood Headwaters Watershed
  • Coyote Watershed
  • East Branch North Fork Feather Watershed
  • Estrella Watershed
  • Honcut Headwaters Watershed
  • Lower American Watershed
  • Lower Bear Watershed
  • Lower Butte
  • Lower Cache Watershed
  • Lower Calaveras-Mormon Slough Watershed
  • Lower Cosumnes-Lower Mokelumne Watershed
  • Lower Cottonwood Watershed
  • Lower Eel Watershed
  • Lower Feather Watershed
  • Lower Pit Watershed
  • Lower Sacramento Watershed
  • Lower Yuba Watershed
  • McCloud Watershed
  • Middle Fork Eel Watershed
  • Middle Fork Feather Watershed
  • Middle Kern-Upper Tehachapi-Grapevine Watershed
  • Middle San Joaquin-Lower Chowchilla Watershed
  • Middle San Joaquin-Lower Merced-Lower Stanislaus Watershed
  • Mill Watershed
  • Mill-Big Chico Watershed
  • North Fork American Watershed
  • North Fork Feather Watershed
  • Pajaro Watershed
  • Panoche-San Luis Reservoir Watershed
  • Russian Watershed
  • Sacramento Headwaters Watershed
  • Sacramento-Lower Cow-Lower Clear Watershed
  • Sacramento-Lower Thomes Watershed
  • Sacramento-Stone Corral Watershed
  • Sacramento-Upper Clear Watershed
  • Salinas Watershed
  • San Francisco Bay Watershed
  • San Francisco Coastal South Watershed
  • San Joaquin Delta Watershed
  • San Pablo Bay Watershed
  • South Fork American Watershed
  • South Fork Eel Watershed
  • South Fork Kern Watershed
  • Suisun Bay Watershed
  • Tulare-Buena Vista Lakes Watershed
  • Upper Bear Watershed
  • Upper Butte
  • Upper Cache Watershed
  • Upper Calaveras Watershed
  • Upper Chowchilla-Upper Fresno Watershed
  • Upper Coon-Upper Auburn Watershed
  • Upper Cosumnes Watershed
  • Upper Cow-Battle Watershed
  • Upper Deer-Upper White Watershed
  • Upper Dry Watershed
  • Upper Eel Watershed
  • Upper Elder-Upper Thomes Watershed
  • Upper Kaweah Watershed
  • Upper Kern Watershed
  • Upper King Watershed
  • Upper Los Gatos-Avenal Watershed
  • Upper Merced Watershed
  • Upper Mokelumne Watershed
  • Upper Pit Watershed
  • Upper Poso Watershed
  • Upper Putah Watershed
  • Upper San Joaquin Watershed
  • Upper Stanislaus Watershed
  • Upper Stony Watershed
  • Upper Tule Watershed
  • Upper Tuolumne Watershed
  • Upper Yuba Watershed

Sacramento Splittail

Scientific Name
Pogonichthys macrolepidotus
Native
Native Species
Identification

Sacramento splittail, juvenile , approximately 10 cm (4”) long. Location: Suisun Marsh, California. Date: 8/6/2007.
Sacramento splittail, juvenile , approximately 10 cm (4”) long. Location: Suisun Marsh, California. Date: 8/6/2007.

Sacramento splittail, adult, from the Cosumnes River, CA. Photo courtesy of Professor Peter B. Moyle.
Sacramento splittail, adult, from the Cosumnes River, CA. Photo courtesy of Professor Peter B. Moyle.

  • Large minnow, to over 40 cm SL
  • Oversized upper lobe of caudal fin, elongate body, adults with hump
  • Slightly sub-terminal mouth, barbels present at margins
  • Hooked pharyngeal teeth, tiny inner-tooth row
  • Coloration: silver, fading with age, dusky olive gray back
  • Breeding adults: caudal, anal, dorsal, and paired fins have red-orange tinge
  • Breeding males: darker than normal, white tubercles on head and bases of fins
  • Fin rays: dorsal 9-10, pectoral 16-19, pelvic 8-9, anal 7-9
  • Lateral line scales: 57-64

 

Life History

 

Sacramento splittail are hearty minnows that live in fluctuating environments and can tolerate relatively high salinities and low oxygen levels (< 1.0 mg/L). Typically they are found in estuarine environments and are commonly found in water with salinities from 10-18 ppt. They prefer slightly lower salinities but can survive short term exposures to water with a salinity as high as 29 ppt. Splittail are usually found where water temperatures range from 5-24°C, though under laboratory conditions they have shown an ability to survive short exposures to temperatures as high as 33°C. These adaptations make splittail well suited for slow moving rivers, sloughs, and alkaline lakes. Sacramento splittail feed on bottom dwelling invertebrates and detritus in low to moderate currents. Young splittail focus their feeding on benthic crustaceans and they show an ability to swim against strong tides and currents. In the Sacramento-San Joaquin Delta splittail feed opportunistically during the day with peak feeding early in the morning. Prey items include clams, crustaceans, insect larvae, and other invertebrates. During high flows they may enter the floodplain where they feed on earthworms. In the Suisun Marsh opossum and then mysid shrimp have been focal points of feeding for the splittail. Sacramento splittail live relatively long lives of up to 5-7 years, possibly longer. Females live longer than males and reach greater total lengths. Splittail typically reach sexual maturity by the end of their second year (around 170 mm SL). Males may mature in their first year (110 m SL) while females may not mature until their third year (215 mm SL). After their third year splittail grow an average of 35 mm/year for the remainder of their life. During winter and spring adult splittail move upstream to forage and later spawn between late February and early July. Spawning is presumably triggered by day length, increased flows, and water temperatures rising to a range of 14-19°C. Spawning occurs in flooded vegetation with older fish spawning first. Peak reproduction occurs in March and April though splittail are fractional spawners, so the process may take months. Typically egg production increases with body size and one large female may produce over 100,000 eggs. Fertilized eggs stick to the flooded vegetation till the embryos hatch 3-7 days later. Hatch time is temperature dependent. Active feeding and swim bladder function in the larvae begins 5-7 days after the hatch. The larvae remain in the vegetation for 10-14 days where they have adequate cover and access to small prey. Young-of-year splittail move into the estuary in April-August where they occupy water less than 2 m deep.

Links to Other Research
Watershed
  • Coyote Watershed
  • Lower American Watershed
  • Lower Bear Watershed
  • Lower Feather Watershed
  • Lower Sacramento Watershed
  • Lower Yuba Watershed
  • Middle San Joaquin-Lower Chowchilla Watershed
  • Middle San Joaquin-Lower Merced-Lower Stanislaus Watershed
  • Sacramento-Stone Corral Watershed
  • San Joaquin Delta Watershed
  • San Pablo Bay Watershed
  • Suisun Bay Watershed

Sacramento Sucker

Scientific Name
Catostomus occidentalis
Native
Native Species
Identification

Sacramento sucker, adult, caught in Putah Creek, California on 26 June 2008 by Teejay O'Rear. Photo by Amber Manfree.
Sacramento sucker, adult, caught in Putah Creek, California on 26 June 2008 by Teejay O'Rear. Photo by Amber Manfree.

Sacramento sucker, juvenile, approximately 15 cm (6”) long. Location: Deer Creek, California (Yuba River basin). Date: 6/20/2007.
Sacramento sucker, juvenile, approximately 15 cm (6”) long. Location: Deer Creek, California (Yuba River basin). Date: 6/20/2007.

Sacramento sucker, young-of-the-year, approximately 5 cm (2”) long.  Location: Deer Creek, California (Yuba River basin). Date: 6/22/2007.
Sacramento sucker, young-of-the-year, approximately 5 cm (2”) long. Location: Deer Creek, California (Yuba River basin). Date: 6/22/2007.

Sacramento sucker (sub-species, Pajaro sucker, Catostomus occidentalis mniotiltus) photographed in a tributary of the upper Salinas River on 11 March 2010, by Royce Larsen, UC Cooperative Extension.
Sacramento sucker (sub-species, Pajaro sucker, Catostomus occidentalis mniotiltus) photographed in a tributary of the upper Salinas River on 11 March 2010, by Royce Larsen, UC Cooperative Extension.

Sacramento sucker (head), caught in Suisun Marsh on 17 July 2008 by Teejay O'Rear. Photo by Amber Manfree.
Sacramento sucker (head), caught in Suisun Marsh on 17 July 2008 by Teejay O'Rear. Photo by Amber Manfree.