Details
Oncorhynchus mykiss
The rainbow trout is a salmonid of cool Nearctic freshwaters. Active across day and night, it takes drifting and swimming prey in clear streams and lakes.
Map: Ecoregions 2017 © RESOLVE (CC BY 4.0) · Natural Earth (PD)
It uses cold, oxygen-rich rivers, streams, and lakes. Gravel beds, inflows, boulders, and woody cover are important freshwater features.
Length is about 30-90 cm and weight about 500-9000 g. A silvery body with black spots and a pink to rainbow side stripe gives the species its name.
It holds position in current and waits for food to pass. Fish may be solitary or loosely grouped and can move between lakes and streams.
It is carnivorous, eating aquatic insects, terrestrial insects, small fish, and crustaceans. It feeds at the surface, in the current, and near the bottom.
Spawning occurs in cool seasons when females dig redds in gravel. Eggs develop among the stones, and fry grow in gentler stream margins.
Its status is listed as Least Concern. It has been widely stocked, but introduced populations can compete or hybridize with native salmonids.
