The tule perch ''Hysterocarpus traskii'' is a

surfperch The surfperches are a family of perciform fishes, the Embiotocidae. They are mainly found in northeast Pacific Ocean (as far south as Baja California), but a few species (genera '' Ditrema'' and '' Neoditrema'') are found in the northwest Pacifi ...

( Embiotocidae) native to the rivers and estuaries of central

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, United States of America. It is the sole member of its genus, and the only freshwater surfperch. The tule perch is small, at most in length, and deep-bodied, with a definite hump shape between the head and the

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

. Color is variable, with a dark back that may have a bluish or purplish cast, and a whitish or yellowish belly. The sides may have a pattern of narrow or wide bars; the frequency of barred patterns varies according to subspecies. The dorsal fin has a noticeable ridge of scales running along its base, and consists of 15-19 spines followed by 9-15 soft rays. The

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

has three spines and 20-16 soft rays, while the

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

s have 17-19 rays. They are fish of the lowlands, inhabiting lakes, sloughs, streams, and rivers, generally in areas with beds of vegetation or overhangs. They generally gather in groups, sometimes in large numbers. Their diet is primarily small invertebrates sucked up from the bottom or picked from the midwater column. The two subspecies of tule perch recognized by FishBase are: * '' Hysterocarpus traskii traskii'' Gibbons, 1854, the Russian River tule perch, originally occurred throughout Clear Lake, the Russian River, the

Sacramento River The Sacramento River ( es, Río Sacramento) is the principal river of Northern California in the United States and is the largest river in California. Rising in the Klamath Mountains, the river flows south for before reaching the Sacramento–S ...

San Joaquin River The San Joaquin River (; es, Río San Joaquín) is the longest river of Central California. The long river starts in the high Sierra Nevada, and flows through the rich agricultural region of the northern San Joaquin Valley before reaching Suis ...

and out into the estuaries around

San Francisco Bay San Francisco Bay is a large tidal estuary in the U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the big cities of San Francisco, San Jose, and Oakland. San Francisco Bay drains water from a ...

and the

Pajaro River The Pajaro River (''pájaro'' is ''bird'' in Spanish language, Spanish) is a U.S. river in the Central Coast (California), Central Coast region of California, forming part of the border between San Benito County, California, San Benito and Santa ...

- Salinas River drainages. It is still common as far north as the

Pit River The Pit River is a major river draining from northeastern California into the state's Central Valley. The Pit, the Klamath and the Columbia are the only three rivers in the U.S. that cross the Cascade Range. The longest tributary of the Sacr ...

, although it has mostly disappeared from the San Joaquin basin. The only unbarred fish occur in this subspecies, about 43% existing in this color pattern. * ''

Hysterocarpus traskii pomo ''Hysterocarpus traskii pomo'' is one of two subspecies of tule perch and is endemic to the Central Valley drainages of California, USA. The subspecies name refers to the Pomo The Pomo are an Indigenous people of California. Historical Pomo t ...

'' Hopkirk, 1974 is found in the Central Valley drainages. The formal description of the tule perch was first read by W. P. Gibbons at a meeting of the

California Academy of Natural Sciences The California Academy of Sciences is a research institute and natural history museum in San Francisco, California, that is among the largest museums of natural history in the world, housing over 46 million specimens. The Academy began in 1853 ...

on May 15, 1854, and then published in the San Francisco newspaper ''The Daily Placer Times and Transcript'' on May 18, making it a rare case of a new species being published in a newspaper rather than book or scientific journal. Gibbons chose the genus name ''Hysterocarpus'' "womb-fruit" referring to the livebearing common to all surfperches. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

honours

John B. Trask John is a common English name and surname: * John (given name) * John (surname) John may also refer to: New Testament Works * Gospel of John, a title often shortened to John * First Epistle of John, often shortened to 1 John * Second ...

(1824-1879), who was a friend of William P. Gibbons and was a

physician A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...

and amateur

geologist A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, althou ...

, he was also a founding member of the

California Academy of Sciences The California Academy of Sciences is a research institute and natural history museum in San Francisco, California, that is among the largest museums of natural history in the world, housing over 46 million specimens. The Academy began in 1853 ...

References

* * Peter B. Moyle, ''Inland Fishes of California'' (University of California Press, 2002), pp. 424–428 *
University of California, Division of Agriculture and Natural Resources; California Fish Website; California Fish Species
{{Taxonbar, from1=Q148825, from2=Q17141294 Embiotocidae Endemic fauna of California Fish of the Western United States Monotypic fish genera Sacramento River Salinas River (California) San Francisco Bay San Joaquin River Fish described in 1854