E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Ameiurus nebulosus (Lesueur, 1819)
Brown Bullhead
Family: Ictaluridae
Photo of species

© Mike Pearson  Email the photographer   (Photo ID #78333)

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Source: Distribution map provided by Don McPhail for E-Fauna BC
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Species Information

Darkly pigmented barbels, strong serrations on the posterior edge of the pectoral spines, and usually 19-21 analy rays. Adults are yellow-brown above and dirty white below. Juveniles are dark above and white below. This species can be confused with the black bullhead (Ameiurus melas), however adults can be separated by the development of serrations on the trailing edge of the pectoral spines—these are srong in the brown bullhead and weak in the black bullhead. For further information see McPhail (2007). (Source: McPhail, J. D. 2007. The Freshwater Fishes of British Columbia. The University of Alberta Press. 620 p.)
Source: McPail, J. D. 2008. The Freshwater Fishes of British Columbia. University of Alberta Press, Edmonton.


Species Biology

Occurs in pools and sluggish runs over soft substrates in creeks and small to large rivers. Also found in impoundments, lakes, and ponds. Rarely enters brackish waters (Ref. 1998). A nocturnal feeder that feeds mollusks, insects, leeches, crayfish and plankton, worms, algae, plant material, fishes and has been reported to feed on eggs of least cisco, herring and lake trout (Ref. 1998). Juveniles (3-6 cm) feed mostly on chironomid larvae, cladocerans, ostracods, amphipods, bugs and mayflies (Ref. 1998). Can tolerate high carbon dioxide and low oxygen concentrations and temperatures up to 31.6 °C although experiments show upper lethal temp. to be 37.5 °C; resistant to domestic and industrial pollution (Ref. 1998). Has been observed to bury itself in mud to escape adverse environmental conditions (Ref. 1998).

Source: FishBase. Page, L.M. and B.M. Burr 1991 A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston. 432 p.


BC Distribution and Notes

This species is an introduction from eastern North America. For many native species, the introduction of brown bullhead into small lakes has been a disaster. For example, on Vancouver Island, Lasqueti Island, and in the lower Fraser Valley, native populations of threespine stickleback (Gasterosteus aculeatus) — including one of the unique benthic–limnetic species pairs — have disappeared following the introduction of brown bullhead. Threespine sticklebacks build their nests on the substrate, and these extirpations probably result from nocturnal predation on their eggs.

Source: Information provided by Don McPhail for E-Fauna BC.
Global Distribution

North America: Atlantic and Gulf Slope drainages from Nova Scotia and New Brunswick in Canada to Mobile Bay in Alabama in USA, and St. Lawrence-Great Lakes, Hudson Bay and Mississippi River basins from Quebec west to Saskatchewan in Canada and south to Louisiana, USA. Introduced into several countries. Several countries report adverse ecological impact after introduction. Asia: Iran and Turkey (Ref. 39702).

Source: FishBase. Page, L.M. and B.M. Burr 1991 A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston. 432 p.

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)
ExoticSNAExoticNot Listed
BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Additional Range and Status Information Links

Additional Photo Sources

General References

Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 2024-06-18 5:42:58 PM]
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