University of California
California Fish Website

Fish Species


 Common Name Clear Lake Tule Perch
 Scientific Name Hysterocarpus traskii lagunae
 Native Yes
 Identification
Tule perch, 13 cm (5”) long. Location: Suisun March. Date: 8/6/2007.
Tule perch, 13 cm (5”) long. Location: Suisun March. Date: 8/6/2007.

Tule perch, barred morph, captured from the Russian River, CA in June 2009. Photo by David Cook, Sonoma County Water Agency.
Tule perch, barred morph, captured from the Russian River, CA in June 2009. Photo by David Cook, Sonoma County Water Agency.

Tule perch, 13 cm (5”) long, frontal view. Location: Suisun March. Date: 8/6/2007.
Tule perch, 13 cm (5”) long, frontal view. Location: Suisun March. Date: 8/6/2007.

Tule perch, 10 cm (4”) long, unbarred morph. Location: Suisun March. Date: 8/6/2007.
Tule perch, 10 cm (4”) long, unbarred morph. Location: Suisun March. Date: 8/6/2007.

Tule perch, 10 cm (4”) long, barred morph. Location: Suisun March. Date: 8/6/2007. Note: the red marks on the pectoral fin, anal fin, and side of this fish are not natural markings, and may be an infection.
Tule perch, 10 cm (4”) long, barred morph. Location: Suisun March. Date: 8/6/2007. Note: the red marks on the pectoral fin, anal fin, and side of this fish are not natural markings, and may be an infection.

Tule perch, juvenile, barred morph, captured from the Russian River, CA on 05/22/2009. Length approximately 2 cm (1
Tule perch, juvenile, barred morph, captured from the Russian River, CA on 05/22/2009. Length approximately 2 cm (1"). Photo by David Cook, Sonoma County Water Agency.

Juvenile Russian River tule perch photographed July 3, 2011 in Sonoma County, CA. Photo by Donald J. Loarie
Juvenile Russian River tule perch photographed July 3, 2011 in Sonoma County, CA. Photo by Donald J. Loarie

Clear Lake Tule Perch, 13 cm (5
Clear Lake Tule Perch, 13 cm (5") long. Location: Clear Lake, near town of Nice, California. Date: 11/3/2016. Photo by Brian Lutz.

PLEASE NOTE: Most of the photos and information shown here are for the species Tule Perch, of which the Clear Lake Tule Perch is a sub-species.

  • Deep bodied, usually < 15 cm TL, 22 cm SL max
  • Small terminal mouth, hump separates head from dorsal fin
  • Distinctive scale patch below dorsal fin
  • Contrasting dorsal/ventral surfaces, dorsal: blue to purple, ventral: white to yellow
  • Various barring patterns: un-barred, narrow-barred, broad-barred
  • Fin spines/rays: dorsal 15-19 spines/9-15 rays, anal 3 spines/20-26 rays, pectoral 17-19 rays
  • Lateral line scales: 34-43
 Life History Tule Perch are most often found in low-elevation lakes, streams, and estuarine environments. They typically require cool, well oxygenated water. These fish prefer water temperatures below 22°C and are scarce in water that exceeds 25°C. Tule Perch have a high salinity tolerance and have been found in water with a salinity as high as 30 ppt. Within a river or stream Tule Perch tend to occupy deep pools that have complex cover in the form of aquatic and overhanging vegetation. They feed on invertebrates, plants, and zooplankton, mostly by swimming along the bottom of the stream. The Perch may move into faster water for feeding by occupying small eddies and backwaters behind rocks and boulders. Tule Perch tend to share habitat with other native fish. In lakes Tule Perch favor deep water and areas where a slight flow might exist from water entering and exiting the basin. In addition these fish are found near tules in areas where the lake floor is made up of gravel and or sand. Tule Perch may form shoals or schools, and are often found associated with centrarchids. While the Perch focus their feeding on the bottom of a lake, they may also forage in the water column. Dietary components in various types of water may include shrimp, crabs, clams, chironomid midges, and aquatic insects. Tule Perch have a relatively elaborate reproductive cycle. Male Perch may “court” females in order to attract them for breeding. Males then inject sperm into the female with a modified anal spine, and each female may mate with multiple males. While the sperm may be injected in July-September, the sperm is not released to fertilize within the female till January. Young Perch then begin to develop within her, slowly at first, and more rapidly in the final two months. In around May or June the female bears 10-60 live fish. The number of young produced increases with body size and may vary from one environment to another. Tule Perch grow most rapidly during the first 18 months of life, and may live up to 7 or 8 years. The majority never exceed 16 cm SL nor do they live longer than 5 years.

 Links to Other Research

Thompson, L.C., G.A. Giusti, K. Weber, R.F. Keiffer. 2013. The native and introduced fishes of Clear Lake: A review of the past to assist with decisions of the future. California Fish and Game 99(1):7-41. Download

Weber, Kristina L., Lisa C. Thompson, Gregory A. Giusti, and Ryan F. Keiffer. 2011. Clear Lake Annotated Bibliography. University of California Cooperative Extension. 226 p. (302 references) Download

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).

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