Freshwater Fishes of the Columbia Basin Return to Table of Contents Return to Species List

Native Fishes: Family Cyprinidae (Chub, Minnows, Dace)

Acrocheilus alutaceus (Agassiz and Pickering)	Chiselmouth
Acrocheilus=sharp lip alutaceus=leathery

Chiselmouth are endemic to the rivers and lakes of British Columbia and the northwestern United States. It was unknown in British Columbia waters until 1950 when a population was discovered in Skaha Lake (Scott and Crossman 1973). This species has a spotty distribution pattern in British Columbia that suggests it requires warmer waters than many other cyprinid species. There has been sporadic historical reports of Chiselmouth in Windermere Lake, in the upper Columbia region, and a single adult specimen was collected in 1957 by H.V. Hopkins near Windermere Lake outlet (RBCM collection records). Recent surveys of Windermere Lake suggest that Chiselmouth are now extirpated from the Upper Columbia. The feeding behaviour of Chiselmouth is unique and, as their common name implies, they posses a sharp chisel-like lower jaw that is used to scrape algae from smooth rocks and submerged logs (Moodie and Lindsey 1972). After the Chiselmouth eats the algae, the algae remains relatively undigested in the fish'slong gut, but the nutritive portions of diatoms contained within the algae are absorbed. Chiselmouths are rare in British Columbia, and little is known about the life-history and habitat requirements of this unique species.

The distribution of Chiselmouth in the Columbia Basin is restricted to below barriers in the Similkameen, Okanagan, Kettle and lower Columbia systems.

Chiselmouth have a long, slender caudal peduncle and a deeply forked caudal fin. The lower jaw is covered with a rigid cartilaginous plate that appears honed to an edge, like that of a chisel.

Couesius plumbeus (Agassiz)	Lake Chub
Couesius=after ornithologist Elliot Coues plumbeus=lead-coloured

Lake Chub have a wide native distribution that includes streams, rivers and lakes throughout Canada. This species is capable of tolerating a wide variety of habitats, and some populations even inhabit hot springs in portions of the Mackenzie Drainage. Lake Chub are a small, schooling, cyprinid fish that mature in their third or fourth year, and are an important diet item for larger piscivorus fish. Females have shorter paired fins, generally grow faster and live longer than the males. Lake Chub come into reproductive condition in early spring, and deposit small, yellow eggs along the rocky margins of streams and lakes. The eggs hatch about two weeks after they are laid, depending on water temperature (Breder and Rosen 1966). The males develop tubercles on their head, pectoral and pelvic fins as they come into breeding condition. It has been suggested that Lake Chub west of the Rocky Mountain Divide are a subspecies that has been isolated from the rest of North America since the Pleistocene Glaciation (McPhail and Lindsey 1970). Like many cyprinid species, Lake Chub are prone to hybridization; and Nelson (1966) and Butcher (1980) provided evidence that Lake Chub and Longnose Dace were hybridizing in the Kananaskis Reservoirs, Alberta.

Lake Chub have a small terminal barbel near the corner of their mouth, and the insertion of their dorsal fin is slightly anterior to the insertion of their pelvic fins when viewed latterly.

In the Columbia Basin, Lake Chub are confined to small lakes in the warm waters of the Kettle, Okanagan and Similkameen systems.

Mylocheilus caurinus (Richardson)	Peamouth Chub
Mylocheilus=grinder lip caurinus=wind from the northwest

This species is endemic to western North America, and is the sole member of the genus Mylocheilus (Bailey et al. 1970). Peamouth Chub are commonly found in the weedy shallows of rivers and lakes, and grow to a maximum of about 35 cm. Peamouth Chub are one of the most abundant cyprinid species in the Columbia Basin, and are easily angled on a variety of baits including dry flies. Near the turn of the last century Peamouth Chub were erroneously advertised as freshwater herring or whitefish, and served up in hotels throughout the Columbia Basin.

Spawning takes place in the inlets, outlets and gravel shallows of lakes during May and June once waters reach about 12ºC (Wydoski and Whitney 1979). During spawning, Peamouth Chub aggregate in schools, then females broadcast release large numbers of sticky, greenish eggs that hatch in seven to eight days depending on water temperatures. Male and female Peamouth Chub are dimorphic during the breeding season, with the ripe males developing tubercles on the head, pectoral and pelvic fins. Breeding males also develop a dark lateral stripe flanked with tinges of red, and exhibit a dark green dorsal surface. Ripe females are less colourful than males, and lack well-developed lateral stripes.

Like many cyprinids, Peamouth Chub hybridize easily with other family members, and in 1856 a specimen was described from the lower Columbia as a new species, Cheonda cooperi (Carl et al. 1967). Nearly a hundred years later a similar specimen was found in Flathead Lake, Montana that was correctly identified as a hybrid between the Redside Shiner and Peamouth Chub (Weisel 1954). A similar case of hybridization has been noted for Northern Squawfish (Ptychocheilus oregonesis) and Peamouth Chub (Scott and Crossman 1973).

Peamouth Chub are currently found throughout the Columbia Basin except the Flathead system. Peamouth Chub can be identified by their deeply forked tail, small mouth that ends in a small terminal barbel and well-developed pelvic auxiliary process (finlette) above the pelvic fin.

Return to Table of Contents Return to Species List

Richardsonius balteatus (Richardson)	Redside Shiner
Richardsonius=after Sir John Richardson balteatus=girdled

Redside Shiners are native to the pacific slope of North America, where they are abundant and widespread in lakes, ponds and slow rivers. The biology of this abundant species has received a lot of attention compared with other cyprinid species because of their close relationship to Rainbow Trout sports fisheries. Redside Shiners were widely introduced into the lakes of the interior of B.C. to provide forage for trout species, but it was later discovered that they out compete and forage on small salmonids (Johannes and Larkin 1961). Great efforts have been mounted to remove Redside Shiners from lakes where they were introduced, but eradication attempts have been unsuccessful and many transplanted populations remain.

Lake-dwelling Redside Shiners make seasonal migratory and daily movement patterns. They inhabit shallow water by day and deeper waters during the night and winter months (Lindsey and Northcote 1963). Tributary stream inhabitants migrate into the stable lower reaches, as water temperatures and photoperiod decreases with approaching winter.

Redside Shiners are seldom found alone, often congregating in schools by the thousands. Redside Shiners spawn in groups of 30-40 during May to early August when males become brilliantly coloured in crimson and gold. Sexual maturity is reached in their third year, and females deposit small, adhesive eggs in multiple lots throughout the breeding season over an unprepared substrate (Scott and Crossman 1973). Redside Shiners are known to hybridize with Northern Squawfish (Ptychocheilus oregonensis), Longnose Dace (Rhinichthys cataractae) and Peamouth Chub (Mylocheilus caurinus) (Carl et al. 1967; Scott and Crossman 1973).

Redside Shiners are common throughout the Columbia Basin, but absent from the Flathead River system.

Redside Shiners are laterally compressed, have a long anal fin base length and the posteriorly mounted dorsal fin has its insertion above the anal fin origin.

Ptychocheilus oregonesis (Richardson)	Northern pikeminnow
Ptychocheilus=folded lip oregonesis=of Oregon

The native distribution of the Northern pikeminnow is typical of species that have survived glaciation in the Columbia Refuge (McPhail 1967). In British Columbia, these endemic minnows are found only in drainages between the Pacific and Rocky Mountain divides. They are common in weedy lakes, slow-moving streams and edge waters of larger rivers in all regions of the Columbia Basin except the Flathead system. Northern pikeminnow, like Peamouth Chub, are one of the most numerous species in B.C., and are commonly caught by anglers on a wide variety of baits including fruit and berries.

Juveniles inhabit the shallow back channels and lake edges, while larger fish dwell along drop-off zones in the summer months (Scott and Crossman 1973). Northern pikeminnow feed on a variety of organisms, but larger individuals are primarily piscivorus. Sexual maturity is achieved at around six years, once the fish reaches about 30 cm in length. Spawning occurs during late May to July when congregations form along lake shores or near tributary streams. Females may spawn many times in a season, and are usually accompanied by many males during breeding.

The head of Northern pikeminnow is somewhat flattened between the eyes, the mouth is large and the maxillary extend to the hind margin of the eye. While most juvenile cyprinids are notoriously difficult to identify, juvenile Northern pikeminnow have a distinct black spot on their caudal peduncle.

Comment on Dace (Rhinichthys)

Distribution of dace species in the Columbia Basin
(RBCM Collections)

The representatives of the this cyprinid genus are comprised of four related species that have been confusing to taxonomists. The Longnose Dace (Rhinichthys cataractae) is widespread throughout North America and is the most common dace in the Columbia Basin. Hybrids between Longnose Dace and Redside Shiner (Rhichardsonious balteatus), and Longnose Dace and Lake Chub (Couesis plumbeus), are relatively common.

The three remaining species of dace in the Columbia Basin are endemic to the Columbia Basin and thought to be closely related. At one time Umatilla Dace (Rhinichthys umatilla) was thought to be a stable hybrid species between Leopard Dace (Rhinichthys falcatus) and Speckled Dace (Rhinichthys osculus). It has since been discovered that Umatilla Dace were present in areas where at least one of the presumed parent species was absent (Peden and Hughes 1980). The origins of Umatilla Dace is still in debate, but the species may have multiple origins and appears variable in the Columbia Basin.

Return to Table of Contents Return to Species List

Rhinichthys cataractae (Valenciennes)	Longnose Dace
Rhinichthys=snout-fish; the snout being prominent cataractae=of the cataract, the original species description was from Niagara Falls

Longnose Dace is a small, wedge-shaped bottom-oriented fish that inhabits the rocky interstices of swift streams and edge zones of some larger lakes throughout north central North America. Unlike many cyprinid species it is not a schooling species and is generally found alone, even while coming into condition during the reproductive season. Spawning time is variable but generally occurs during late summer (Breder and Rosen 1966). There is some evidence to suggest that two or more cohorts may be produced per spawning year. Males defend a territory and guard over the adhesive, nearly invisible eggs deposited by a single female. Like many cyprinid species with overlapping reproductive periods, hybrids occur between Longnose Dace with Lake Chub (Couesius plumbeus) and with Redside Shiners (Richardsonius balteatus) (Nelson 1966; Butcher 1980; Scott and Crossman 1973).

Longnose Dace are easily identified by their wedgelike shape, small eyes, thick caudal peduncle, non-protractile ventral mouth and yellow-olive green colouration.

Longnose Dace are distributed throughout the Columbia Basin, except for portions of the Kettle River above the barrier at Cascade, B.C. and the Flathead system.

Rhinichthys falcatus (Eigenmann & Eigenmann)	Leopard Dace
Rhinichthys=snout-fish; prominent snout falcatus=sickle-shaped

Leopard Dace are a small cyprinid fish that have a distribution restricted to the Fraser and Columbia River systems east of the Cascade Mountains. Leopard Dace inhabit streams, larger rivers and occasionally lake margins near outlets. This species prefers slower waters than its congener, the Longnose Dace (Rhinichthys cataractae) (Gee and Northcote 1963).

Leopard Dace develop tubercles about their head during reproductive periods, and usually spawn during July and August. Breeding females are accompanied by many males and deposit adhesive eggs over unprepared gravel (Scott and Crossman 1973). The males exhibit a scarlet spawning dress on the lips and points near the insertion of their pelvic and pectoral fins.

Leopard Dace have a long, slender body with mottled leopard spots along their lateral and dorsal surfaces. Fleshy stays connect the rays of the pelvic fin to the lateral surface of the body wall. Leopard Dace is the only member of the genus Rhinichthys that has pelvic stays.

In the Columbia Basin Leopard Dace have a restricted distribution and are absent from the Upper Columbia, Upper Kootenay and above barriers in the Similkameen, Kettle and Lower Columbia systems.

Rhinichthys osculus (Girard)	Speckled Dace
Rhinichthys=snout-fish; prominent snout osculus=small mouth

The northern limit of the Speckled Dace distribution is found in the Canadian portions of the Columbia Basin. The only occurrence of this species in British Columbia is from the Kettle and Granby rivers, where it is found above and below the barrier at Cascade. This distribution suggests that Speckled Dace was one of the first fish to disperse into the upper Columbia post-glacially.

In British Columbia, adult Speckled Dace are found in shallow waters with slow to moderately strong current over a cobble substrate (Peden and Hughes 1981). Spawning usually occurs once a year from June through August in animals older than two years (Cannings and Ptolemy 1998). During reproductive periods males develop a red spawning dress similar to Leopard Dace (Rhinichthys falcatus). Breeding occurs in riffles with a clean gravel substrate and males clean and prepare the gravel with their mouths prior to spawning. During breeding, many males accompany a single female which deposits adhesive eggs into prepared substrate.

Speckled Dace have a moderately robust body with a short caudal peduncle. The mouth is located sub-terminal, and does not overhang the lower jaw like that of the Longnose Dace (Rhinichthys cataractae). The young have strong lateral bands that are absent in the mottled adults.

Return to Table of Contents Return to Species List

Rhinichthys umatilla (Gilbert and Evermann)	Umatilla Dace
Rhinichthys=snout-fish; prominent snout umatilla=first described from Umatilla, Oregon

Umatilla Dace have a restricted distribution in Western North America, occurring only in the Columbia Basin (Hughes and Peden 1989). This species has been thought to be of hybrid or introgressed origin, with Leopard Dace (Rhinichthys falcatus) and Speckled Dace (Rhinichthys osculus) being the proposed parent species (Peden and Hughes 1988a). Recent evidence suggests that Umatilla Dace are of a variable hybrid origin, but the populations are stable and separate from their parent species. The occurrence of Umatilla Dace in drainages that do not support one of the proposed parent species further suggests that Umatilla Dace is a viable, but variable, species that may have a polyphyletic hybrid past (Cannings and Ptolemy 1998). The Umatilla Dace prefers faster waters than does Leopard Dace when the two species are found together, and like other members of the genus Rhinichthys, Umatilla Dace probably breed in the late spring and summer (Peden and Hughes 1988b).

In the British Columbia portion of the Columbia Basin Umatilla Dace prefer larger riverine habitat with large cobbles, and are found in the Similkameen, Kettle River below Cascade, lower Kootenay and lower Columbia rivers.

Umatilla Dace exhibit inconspicuous barbels, which are often very difficult to see, at the corner of the mouth, and have poorly developed pelvic fin stays compared to Leopard Dace. The dorsal fin insertion is above the pectoral fin and is commonly falcate along the posterior edge.