sucker species in the Columbia Basin
|Catostomus catostomus (Forster)|
Longnose Suckers are one of the most common sucker species and they are distributed throughout Canada and eastern Siberia and have been sold commercially in frozen fillets as mullet (Scott and Crossman 1973). Several regional longnose subspecies designations have been suggested throughout Canada, and hybrids between catostomid species are common (Nelson 1973; Nelson and Paetz 1992). Longnose Suckers can grow up to a maximum length about 60 cm, and a weight of more than 3 kg.
The species matures between five to seven years, and come into reproductive condition during the early spring shortly after cover ice melts and temperatures rise to 5°C (Scott and Crossman 1973). At breeding time, male Longnose Suckers become coloured with a lateral band with a red stripe, and develop large nuptial tubercles on their head, anal and caudal fins. Females shed large numbers of small white adhesive eggs over unprepared gravel while accompanied by multiple males. Experimentally raised eggs hatch in 11 days at 10° C and the hatchlings remain in the gravel for one or two weeks before leaving the nest site (Wydoski and Whitney 1979).
Longnose Suckers are distributed throughout the Columbia Basin, except in the waters above barriers in the Similkameen system.
Longnose Suckers have a ventrally located mouth that suits its benthic diet. The lower lip is completely cleft and both lips are covered by coarse, fleshy papillae. The snout is long and extends well beyond the upper lip. The body is covered with small scales and is elongate and cylindrical in shape.
|Catostomus columbianus (Eigenmann and Eigenmann)|
columbianus=of the Columbia
The distribution of the Bridgelip Sucker is restricted to the waters of northwestern North America. This species inhabits lakes and rivers in backwaters and edges of the main current with sandy or muddy substrates. The body is cylindrical in shape that reaches an average length of 30 cm.
Bridgelip Suckers mature at as little as 13 cm in length, and spawn during late spring after ice breakup. Breeding males develop an orange lateral band and tubercles on their anal, lower caudal fin, and scales on posterior portions of the body as breeding season approaches. It is thought that females broadcast spawn their small yellow eggs like other catostomid species (Wydoski and Whitney 1979).
The diet of the Bridgelip Sucker includes aquatic insect larvae and crustaceans, although the flat mouth, edged frenum and long intestinal tract suggests that this sucker supplements its diet by scraping algae off bottom rocks.
The Bridgelip Sucker can be distinguished from other suckers -- except the Mountain Sucker (Catostomus platyrhynchus) -- by the incomplete cleft in the lower lip. Bridgelip Suckers lack the distinct notches at the corner of the mouth separating the upper and lower lips as seen in the Mountain Sucker.
In the Columbia Basin Bridgelip Suckers are present below barriers on the lower Columbia, lower Kootenay, Okanagan and Similkameen rivers.
|Catostomus macrocheilus (Girard)|
The distribution of the Largescale Sucker is restricted to western North America where it inhabits weedy portions of lakes and backwaters of larger rivers. The species can reach a maximum length of 60 cm, can weigh up to 3 kg and can live as long as 11 years. Males first breed at an age of five years, and females usually mature a year later (Carl et al. 1967). This species is not sexually dimorphic except during reproductive periods when males develop horny tubercles on their anal and lower caudal fin, and accentuate the distinct dark band extending below the lateral line along the lateral surface.
Spawning occurs from late April into June once water temperatures reach 7-9° C. Females release up to 20,000 yellow, adhesive eggs along river margins and lake outlets during breeding, and are commonly accompanied by many males. The eggs hatch in about two weeks, at which time the fry are pelagic and feed on zooplankton with their terminal mouths. The positions of the mouths of the fry gradually turn subterminal as they move into deeper water and feed on larger benthic prey. Largescale Suckers commonly spawn in similar habitats and during similar periods as the Longnose Sucker (Catostomus catostomus) and Bridgelip Sucker (Catostomus columbianus), and hybrids have been reported (Wydoski and Whitney 1979; Scott and Crossman 1973).
Largescale Sucker has a thick body covered with large scales that are easily seen with the naked eye. The ventrally placed mouth has a deep cleft in its lower lip, but the snout does not overhang its mouth like that of Longnose Sucker (Catostomus catostomus).
The Largescale Sucker is abundant in all regions of the Columbia system except the Flathead system.
|Catostomus platyrhynchus (Cope)|
Mountain Sucker is a small species restricted to mountainous regions of western North America. This rare endemic species has a very restricted distribution in south central British Columbia. Mountain Suckers inhabit cool, clear mountain streams of moderate current with sand, gravel and cobble substrates. The Mountain Sucker was unknown in British Columbia until 1955 and the species was known previously under the name of Pantosteus jordani. The genus Pantosteus was later considered a subgenus of Catostomus, and the groups were later merged (Carl et al. 1967). Mountain Suckers reach sexual maturity between three to five years of age, and males often mature a year earlier than females. Spawning occurs in riffles of streams adjacent to pools during late spring and early summer when waters are between 10.5-18.8°C (Wydoski and Whitney 1979).
The horny edges of the lower jaw of the Mountain Sucker incorporate a chisel-like sheath. Diet studies have found large quantities of diatoms and filamentous algae in the gut, suggesting that the Mountain Sucker scrapes its mouth over rocky substrate to supplement its diet.
Mountain Sucker's body is thick anteriorly, but becomes compressed towards at the narrow caudal peduncle. Mountain Sucker can be distinguished from other suckers by its incompletely cleft lower lip that is flanked by two notches separating the upper and lower lips.
Mountain Suckers are known only in the Similkameen system in the Columbia Basin, and these populations may be hybridizing with Bridgelip Suckers (Catostomus columbianus).
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