Columbia River Redband Trout - Oncorhynchus mykiss gairdneri
Columbia River Redband Trout are a native trout of western North America. There is considerable variation in the life history in this group of trout. Resident stream populations are found throughout the Columbia River basin. A lake variation known as Kamloops are found in some larger lakes in the Columbia and Frasier River (British Columbia) basins. A third variation is the steelhead that migrated from the ocean as far as the upper Snake River, Idaho (almost 1000 miles) (Behnke 1992).
Characteristics vary considerably among populations of Montana's stream-resident Columbia River Redband Trout, but generally they can be differentiated from the non-native Coastal Rainbow Trout by larger more rounded spots, parr marks that tend to remain into adulthood and are more orange-red around the lateral line surrounded by greenish-yellow, rather than pink-red around the lateral line surrounded by dark green and silver like Coastal Rainbow Trout. Columbia River Redband Trout also have very distinct white tips on the anal, dorsal and pectoral fins.
Western Hemisphere Range
Summary of Observations Submitted for Montana
Number of Observations:
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(Observations spanning multiple months or years are excluded from time charts)
Columbia River Redband Trout are typically a stream-resident fish that make short spawning migrations either in the same stream or often into smaller tributaries.
Columbia River Redband Trout prefer cool, clean, relatively low gradient streams but, in some circumstances, are able to withstand wider temperature variations than their cousins the Westslope Cutthroat Trout.
Interior Columbia River Redband Trout feed mainly on aquatic insects but eat what is available to them. Large adults also eat fish. River populations are mostly insect eaters, while zooplankton and forage fish are important in Lake Koocanusa.
Populations of native Columbia River Redband Trout, Westslope Cutthroat Trout and introduced Coastal Rainbow Trout coexist in the Kootenai River drainage. Interestingly, Columbia River Redband Trout have hybridized with Westslope Cutthroat Trout in some drainages and these crosses are considered to be naturally occurring and historic. Hybridization between Columbia River Redband Trout and Coastal Rainbow Trout, on the other hand, is considered to be a danger to the continued existence of Columbia River Redband Trout.
Columbia River Redband Trout reach sexual maturity in 2 to 3 years. They spawn from late April through mid-June, depending on water temperatures. The fry typically emerge from the gravel in mid-July.
- Literature Cited AboveLegend: View Online Publication
- Behnke, R. J. 1992. Native trout of western North America. American Fisheries Society Monograph 6.
- Additional ReferencesLegend: View Online Publication
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- Antonelli, A.L., R.A. Nussbaum and S.D. Smith. 1972. Comparative food habits of four species of stream-dwelling vertebrates (Dicamptodon ensatus, D. copei, Cottus tenius, Salmo gairdnei) Northwest Science 46: 277-289.