Scientific Name: Cottus hubbsi
Other/Previous Names: Columbia Mottled Sculpin ,Cottus bairdi hubbsi,Cottus bairdii hubbsi
Taxonomy Group: Fishes
Range: British Columbia
Last COSEWIC Assessment: November 2010
Last COSEWIC Designation: Special Concern
SARA Status: Schedule 1, Special Concern
Image of Columbia Sculpin
The Columbia Mottled Sculpin is a small fish that reaches a maximum 10 to 11 cm in length. It is a typically shaped sculpin with dark mottling on the fins, tail and body.
Distribution and Population
This species occurs in the Columbia, Flathead, Similkameen and Kettle rivers as well as some of their tributary streams in British Columbia and the adjacent United States. Populations are not overly abundant but seem to be near natural historical levels in the Similkameen River. Only a small portion of the Kettle River in Canada is suitable and populations there are stable but are probably supported by populations in the adjacent portion of the river in the United States. In the Columbia River, populations are low and are very threatened because of hydroelectric dams and reservoirs.
The Columbia Mottled Sculpin is generally known from rocky riffle habitats in rivers and streams, but may sometimes occur in lakes as well.
Columbia Mottled Sculpins inhabit river pools in rocky areas below riffles where they disperse to no more than a few hundred metres, only to move back into faster current during the reproductive season. They begin breeding at about two years of age. Females reach maturity when as small as 55mm long, but most individuals become mature when about 75 mm long. Males are generally bigger than females. Females select the larger males who usually have a competitive advantage and defend the best territories. Mottled Sculpins spawn in May or June. Each female spawns once a year and lays all her eggs (over 100) in a single hemispherical mass in a nest that measures from 12 to 37 cm in diameter. Females deposit their egg clusters on or under rocks where there is a steady flow of water. More than one female may contribute to an egg cluster in one nest. Males are polygamous and usually breed with 2 to 4 females, but can breed with more. They remain near their nests during egg laying (as long as 5 weeks), incubation (1 to 2 weeks) and through the early fry stage (as long as 2 weeks), and may fan both the eggs and newly hatched fry with their pectoral fins. Because the Mottled Sculpin is a bottom dweller, extensive movements of juveniles or adults are unlikely. The eggs as well as the fry are relatively large compared to other fish of similar size. These adaptations allow the young fry to drift less downstream from favoured riffle habitats and settle into backwater pools until they are strong enough to enter riffle currents. The total distance of dispersal of these juveniles is probably less than 200 m. The species as a whole disperses slowly with reduced movement from stream to stream, which results in genetic isolation of sub-populations. Mottled Sculpins fed on aquatic insects that occur under rocks or in the fine film of algae that covers rocks. There are a few records of sculpins feeding on other fish or their eggs.
This species is restricted to portions of rivers that have suitable habitat, and such portions are relatively limited in extent in Canada. In addition, competition with other sculpin species limits the Columbia Mottled Sculpin to certain portions of rivers; other species are more effective competitors in slower or faster waters. Sculpin populations have been impacted by unnatural fluctuations in water levels, temperature and flow as a result of release of water from hydroelectric and storage reservoirs. Controlled water flow has created conditions more suitable to other species. Dams have eliminated suitable habitats in some areas. Agriculture, mining, logging, pollution from lumber mills, sewage treatment facilities, etc., and other types of human disturbance have had detrimental effects. In the past, lake poisoning programs exterminated the species in some areas.The extraction of coal from the Flathead River area would pose the greatest threat to the species. The coal project would entail the building of a village, roads and electrical transmission lines, and the possible diversion of Howell Creek into the Flathead River. These disturbances could seriously degrade the habitat of the sculpin in the Flathead River and thus adversely affect its population size.
Federal ProtectionMore information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
The federal Fisheries Act prohibits destruction of fish habitat.
Provincial and Territorial Protection
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
4 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Management Plans (1 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
COSEWIC Status Reports
COSEWIC Annual Reports
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