Oncorhynchus mykiss

Identification Tips:

• Black spots on back, sides, dorsal fin and tail
• Widely variable colouration and marking patterns
• Fry <30 mm have black leading edge of dorsal fin • Very similar to Cutthroat Trout at all life stages except adult steehead • Upper jaw short; does not extend behind eye when mouth is closed (Cutthroat Trout does)

Conservation Status:

British ColumbiaCanadaNatureserve
COSEWICSpecies at Risk Act
Not at Risk (Yellow List)Not at RiskNone

Information Source: BC Conservation Data Centre: http://a100.gov.bc.ca/pub/eswp/

Life History:

• Spawn in later winter/early spring; usually peaks in February
• Three general life history types; Resident, Freshwater Migratory and Sea Run (known as Steelhead)
• Many variations of these types within and among populations
• Steelhead typically go to sea after 2 or 3 years in fresh water
• Age of maturity varies from1 year for small resident stream fish to 4+ years for larger lake or ocean going fish.
• Unlike Pacific Salmon, some Rainbow Trout and spawn in more than one year.
• Steelhead enter freshwater in most months of the year; most coastal populations in winter, interior populations in summer. They may remain in the river for up to 6 months before spawn
• Juveniles and small resident fish typically feed on insects drifting in streams
• Larger adults eat other fish and may be cannibalistic
• Some lake dwelling fish eat plankton

Habitat:

• Require cool-water; preferably < 17 C • Spawn in spring in gravels of rivers and streams, usually in currents less than 90 cm/s and depths less than 2.5 m • In rivers adults occupy all parts of the channel, but typically overwinter in deeper pools with abundant cover In lakes they use all parts of the lake, but are most abundant near cover

Range:

British Columbia
• Western flowing rivers throughout BC
• Upper Peace River watershed

Global
• Coastal drainages from Central Baja California to Alaska
• Northeastern Siberia
• Widely introduced including Great Lakes, New Zealand, and South America

Comments:

• Thompson River and Chilcotin River stocks of Steelhead are listed as endangered by COSEWIC. These fish migrate through the Fraser Valley from the ocean to reach their spawning grounds.
• Steelhead stocks in general are in decline in BC but Rainbow Trout overall are abundant and secure.

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