Species Profile

Columbia Sculpin

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


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Quick Links: | Photo | Description | Distribution and Population | Habitat | Biology | Threats | Protection | National Recovery Program | Documents

Image of Columbia Sculpin

Columbia Sculpin Photo 1

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Description

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.

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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.

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Habitat

The Columbia Mottled Sculpin is generally known from rocky riffle habitats in rivers and streams, but may sometimes occur in lakes as well.

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Biology

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.

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Threats

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.

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Protection

Federal Protection

More 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

To know if this species is protected by provincial or territorial laws, consult the provinces' and territories' websites.

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Documents

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

  • COSEWIC Assessment and Status Report on the Columbia Sculpin Cottus hubbsi in Canada (2011)

    The Columbia Sculpin is a small, bottom-dwelling fish with a body shape that tapers from a relatively large head and pectoral fins to a narrow caudal (tail) fin area. The Columbia Sculpin reaches a maximum total length of about 110 millimeters. The Columbia Sculpin is distinguished from other co-occurring sculpins by a relatively long head, a complete lateral line, and striking broad, dark bars on the caudal fin, and oblique dark bars on the anal fin. There is no evidence of multiple designatable units with the Columbia Sculpin.

Response Statements

  • Response Statement - Columbia Sculpin (2011)

    In Canada, this small freshwater fish is endemic to the Columbia River basin where it has a small geographic distribution. It is a bottom-dwelling and sedentary fish as an adult, making it particularly susceptible to declines in habitat area and quality from drought and changes in water flow. It is close to meeting Threatened status owing to its small geographic range, relatively few locations and ongoing declines in habitat quality.

Management Plans

  • Management Plan for the Columbia Sculpin (Cottus hubbsi) in Canada (2012)

    Columbia sculpin are endemic to the Columbia River mainstem and tributaries downstream of Arrow Lakes. In B.C. they have been captured in the Similkameen, Tulameen, Kettle, Columbia, and Kootenay Rivers. In the United States (USA), the Columbia sculpin inhabits most of the Columbia River drainage downstream of the Montana – Idaho border, including the Snake River drainage downstream of Shoshone Falls, Idaho.  Abundance and distribution trends in Canada are not known.

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2010 - 2011 (2011)

    Under Canada’s Species at Risk Act (SARA), the foremost function of COSEWIC is to “assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species”. COSEWIC held two Wildlife Species Assessment Meetings during the past year assessing the status or reviewing the classification of a total of 92 wildlife species.