Smallmouth Bass

Micropterus dolomieu

Identification Tips:

• Spines in dorsal and anal fins
• Red eyes
• Mouth small; upper jaw extends to middle of eye (past eye in Largemouth Bass)
• Membrane joins pelvic fins (absent in Largemouth Bass)
• Juveniles have thin dark vertical bars along mid-line and a prominent orange mark at base of tail
• Most have 2 or 3 dark lines radiating backwards from eye

Conservation Status:

British ColumbiaCanadaNatureserve
COSEWICSpecies at Risk Act
Introduced SpeciesNot AssessedNoneG5

Information Source: BC Conservation Data Centre:

Life History:

•Breed in spring; males court female and constructs nest dish-like nest in sand or gravel; usually in less than 1 m depth and near cover
• Males defend nest and fry for several weeks after hatch
• Mature in 2-5 years and may live for 10-15 years
• Voracious predators; adults eat primarily fish and crayfish
• Fry and small juveniles eat smaller invertebrates and zooplankton


• Lakes and slow moving streams
• Usually over sand or rock bottom and near cover


• Eastern North America; Greatlakes to southwestern Quebec and south to Oklamhoma and northern Alabama
• Introduced to British Columbia, Washington, Oregon, California, Idaho and to cool waters on other continents

British Columbia
• Introduced by Government biologists to lakes in Kootenays and southern Vancouver Island in 1901 and to Saltspring Island in 1920
• Present in Okanagan Lakes since 1960's, Quesnel area since early 2000's, and Fraser Valley more recently


• Believed responsible for disappearance of native Threespine stickleback and Peamouth populations from a number of lakes on southern Vancouver Island

Primary Information Source:
McPhail, J.D. 2007. The Freshwater Fishes of British Columbia. University of Alberta Press. Edmonton, Alberta.