Rainbow Trout
Rainbow Trout / Steelhead (Oncorhynchus mykiss) are members of the Family Salmonidae (Salmonids). Their native range included the Pacific Coast of North America and parts of East Asia. Do to human introduction, they can now be found on all continents except Antarctica.
Rainbow Trout and steelhead are the same species, but some of members of the species stay in fresh water and others migrate between the ocean and freshwater. The members that migrate out to sea are called steelhead; whereas the others, that stay in freshwater, are rainbow trout. Sockeye Salmon (Oncorhynchus nerka) also can stay in fresh water without going to sea; those that do so are called kokanee. Steelhead mitigrate from the sea up rivers and streams to spawn like salmon. After spawning, steelhead are able to return to the ocean and later spawn again. Salmon, however, are not able to do this. They die in the fresh water shortly after spawning.
Rainbow trout and steelhead have small black spots covering their back, caudal fin, and dorsal fin. Rainbow trout typically range in length from 12 to 18 inches (30 to 45 cm) whereas the steelhead range from 20 to 40 inches (50 to 100 cm). Both rainbow trout and steelhead start life with a red/pink stripe on their sides. Rainbow trout keep stripe, but steelhead lose it when they go out to sea.
Rainbow trout prefer cold lakes or moderate to fast moving streams and rivers; hence, dams often decrease their habitat. The young feed on zooplankton, and the adults eat insects, fish eggs, small fish, mollusks, and crustaceans.
