Found in clear, cold, deep water of lakes and tributary streams; occasionally found in brackish water in the Arctic (Ref. 5723). Moves from lakes into inlet streams or from slow, deep pools into shallow, gravel-bottomed portions of streams to spawn (Ref. 27547). Feeds on benthic invertebrates (Ref. 1998). Young are preyed upon by other fishes and fish-eating birds; while adults in spawning streams are taken by mammals, osprey and eagles (Ref. 1998). Feeds mainly on benthic invertebrates as well as on insects and plants (Ref. 1998).