The California roach (''Hesperoleucus symmetricus'') is a

cyprinid Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest ...

fish Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...

native to western

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

and abundant in the intermittent streams throughout central

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

. Once considered the sole member of its genus, it has recently been split into a number of closely related species and subspecies.Baumsteiger J, Moyle PB 2019
A reappraisal of the California Roach/Hitch (Cypriniformes, Cyprinidae, Hesperoleucus/Lavinia) species complex
Zootaxa 4543 (2): 221–240

Characteristics of fish in the ''Hesperoleucus symmetricus'' species complex

These fishes are of a relatively chunky body shape, with a largish head and large eyes, but a small mouth oriented downwards. The color is a darker grayish-bluish above, and a dull silver underneath. During the breeding season, red-orange patches appear on the chin, operculum, and at the bases of pectoral, pelvic, and anal fins. The smallish dorsal fin has 7-10 rays, while the anal fin has 6-9 rays. They never get large, the maximum known being about 11 cm. Mainly bottom feeders, filamentous algae are the main part of their diet, followed by aquatic insects and crustaceans. They will also opportunistically eat insects and crustaceans at the surface. In turn, they are eaten by other fish, in particular green sunfish. Spawning occurs mainly from March through June. They move into shallow, flowing water, over bottoms covered with small rocks, and form up into schools. Females lay a few eggs at a time, eventually putting down from 250 to 900 eggs each. The adhesive eggs are laid in crevices, where they stick to the rocks, and then the males fertilize them. The fry continue to dwell in the crevices until they are strong enough to swim actively.

California roaches seem to be resilient fishes that take advantage of the intermittent waters of central California under conditions too difficult for other fishes. As the springtime streams dry up in summer, roaches accumulate in large number in pools, which may be alkaline, hot (up to 95 °F), and low in oxygen. They also seem to cope well with sewage-polluted waters. The distribution of the species complex comprises 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� ...

/ San Joaquin River drainage, including

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 ...

and Goose Lake, and many of the small coastal streams ( Russian River, Pajaro River, Salinas River, Adobe Creek, Permanente Creek, etc.). Populations in southern California and in Warner Valley, Oregon, may be introductions.

Taxonomic subdivision

In a recent revision of the California roach, previously considered a single species, it was split into four distinct species and two additional subspecies: * ''Hesperoleucus parvipinnis'' — Gualala roach * ''Hesperoleucos mitrulus'' — northern roach * ''Hesperoleucus venustus'' — coastal roach ** ''H. v. navarroensis'' — northern coastal roach ** ''H. v. subditus'' — southern coastal roach * ''Hesperoleucus symmetricus'' — California roach ** ''H. s. symmetricus'' — California roach ** ''H. s. serpentinus'' — Red Hills roach

References

External links

UC Davis California Fishes website
{{Taxonbar, from=Q3768513 Leuciscinae Fish of the Western United States Fish of North America Sacramento River San Joaquin River Fish described in 1854 Taxa named by Spencer Fullerton Baird