Oncorhynchus mykiss

Fishes

California Trout, Rainbow Trout, Redband Trout, Steelhead, truite arc-en-ciel

Rainbow Trout (Oncorhynchus mykiss) are native to the Pacific Slope of North America, from Kuskokwim Alaska; to Rio Santo Domingo (Baja California), and from the upper MacKenzie River (Arctic Basin) Alberta and British Columbia, and to Northeast Asia (Russia-Japan-China).. Rainbow Trout have both permanent freshwater populations and anadromous stocks, known as 'Steelhead'.  Steelheads grow larger, and are more silvery in color, but these differences are environmental, rather than genetic.  'Steelhead' range through the cooler coastal waters of the northern Pacific. They tolerate temperatures of 0-28 “C Rainbow Trout were widely introduced in eastern North America by the United States Fish Commission and state agencies, and are now introduced by many state agencies in non-native drainages in 48 US states and at least 110 countries. They are established in ~50 countries, and probably established at least 15 more. In many locations, it is dependent on annual stocking from hatcheries. However, this fish is widely established in the Great Lakes, and the St. Lawrence estuary and Gulf, with some established, anadromous populations.  Steelhead are extensively raised in aquaculture in Atlantic Canada and Norway, with some escapes, but limited establishment. On the Atlantic Coast, they occur in coastal watersheds, from Newfoundland to Virginia, but southern populations in freshwater are strongly dependent on stocking, with occasional occurrences in marine waters.