Biology

Often schooling, occurring mainly in freshwater (in large rivers, reservoirs, lakes, and swamps). Prefer the presence of smooth, steep-sided surfaces such as dams, cement-lined pools and rip rapped streams (Ref. 39049). But adults are also found in brackish or saline water of estuaries and bays (up to 32.3 ppt salinity (Ref. 39050); juveniles to about 15 ppt). Larvae are pelagic probably found only in freshwater (Ref. 39046). Filter-feeders, but not entirely herbivorous since recorded food items include copepods, cladocerans and fish fry. Also feed on organic material of sand and detritus bottoms (Ref. 9114). Breed in the spring and in autumn, in freshwater, near or over plants or other objects. Eggs adhere to aquatic vegetation (Ref. 4639). Caught exclusively in fresh waters and sometimes in mouths of rivers (Ref. 9291). Also Ref. 58302.