Tule perch
Encyclopedia
The tule perch Hysterocarpus traskii is a surfperch (Embiotocidae
) native to the rivers and estuaries of central California
, United States of America. It is the sole member of its genus, and the only freshwater surfperch.
The tule perch is small, at most 15 cm in length, and deep-bodied, with a definite hump shape between the head and the dorsal fin
. 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 has 3 spines and 20-16 soft rays, while the pectoral fins 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 tule perch occurs in three separate areas in California, which have become differentiated into subspecies:
The formal description of the tule perch was first read by W. P. Gibbons at a meeting of the California Academy of Natural Sciences 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, and traskii (sometimes seen as traski) in honor of J. B. Trask who sent Gibbons the first specimens of this fish.
Embiotocidae
The surfperches are a family, Embiotocidae, of perciform fishes. They are found in coastal waters of the northern Pacific and grow up to 45 cm long....
) native to the rivers and estuaries of central California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, United States of America. It is the sole member of its genus, and the only freshwater surfperch.
The tule perch is small, at most 15 cm in length, and deep-bodied, with a definite hump shape between the head and the dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
. 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 has 3 spines and 20-16 soft rays, while the pectoral fins 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 tule perch occurs in three separate areas in California, which have become differentiated into subspecies:
- Hysterocarpus traskii traskii originally occurred throughout the Sacramento RiverSacramento RiverThe Sacramento River is an important watercourse of Northern and Central California in the United States. The largest river in California, it rises on the eastern slopes of the Klamath Mountains, and after a journey south of over , empties into Suisun Bay, an arm of the San Francisco Bay, and...
-San Joaquin RiverSan Joaquin RiverThe San Joaquin River is the largest river of Central California in the United States. At over long, the river starts in the high Sierra Nevada, and flows through a rich agricultural region known as the San Joaquin Valley before reaching Suisun Bay, San Francisco Bay, and the Pacific Ocean...
and out into the estuaries around San Francisco BaySan Francisco BaySan Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...
, and is still common as far north as the Pit RiverPit RiverThe 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...
, 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 lagunae, the Clear Lake tule perch, is native to Clear Lake and the two Blue Lakes. Although threatened by alien fish introductions and loss of habitat, it remains common in the lake. A broad-barred color pattern is common only in this subspecies, at 27% of individuals.
- Hysterocarpus traskii pomoHysterocarpus traskii pomoThe Russian River tule perch is one of three subspecies of tule perch and is endemic to the Russian River. The subspecies name refers to the Pomo tribe of native Americans who occupied the region.-References:...
, the Russian River tule perch, occurs only in the Russian RiverRussian River (California)The Russian River, a southward-flowing river, drains of Sonoma and Mendocino counties in Northern California. With an annual average discharge of approximately , it is the second largest river flowing through the nine county Greater San Francisco Bay Area with a mainstem 110 miles ...
and the lower parts of its tributaries.
The formal description of the tule perch was first read by W. P. Gibbons at a meeting of the California Academy of Natural Sciences 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, and traskii (sometimes seen as traski) in honor of J. B. Trask who sent Gibbons the first specimens of this fish.