Inhabits virtually any body of water, standing or flowing, large or small (Ref. 5723). Most common in gravel-bottom pools and runs of streams and along rocky lake margins (Ref. 5723). Mostly in shallow water, but may move to deeper parts of lakes during hot weather (Ref. 27547). Feeds on zooplankton, algae, terrestrial and aquatic insects, and small fishes (Ref. 1998).