Main Menu

ANR Fish Workgroup

Fish People

California Fish Species

Fish Search By Location

Cooperative Extension Links

California Fish Website Species Search

Cutthroat Trout, Oncorhynchus clarki
		Appearance and Identification: · 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 < 8cm TL) · 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 Cutthroats have: o More slender body o Larger mouth o Basibranchial teeth-found on bottom of throat · Coloration of Cutthroat sub-species: o Coastal: similar to rainbow, but heavier spotting, especially in posterior and ventral halves o Lahontan: fewer larger spots than coastal form, dark olive to reddish brown body o 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 cutthroats 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 of the 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 cutthroats 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 female fish cover the redds with gravel. Egg production increases with body size: females measuring 200-400 mm will produce a mean 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 don’t live longer than 7 years with a maximum life of 10 years.
Inland Paiute and Lahontan cutthroat Links to Other Research
	Here's a list of California watersheds where Cutthroat trout may be found. © 2003 - Regents of the University of California Division of Agriculture and Natural Resources Communication Services E-Mail Web Master ANR Non-Discrimination Statement