Gregarious. Year-class success appears to be determined during fist 2 months of life, may be correlated with environmental conditions during larval stages (Hill et al. 1989). Growth and development rates vary widely, depending on conditions. Parasitic infection rarely cause mortalities in wild populations unless fishes are under stress (Hill et al. 1989). Summer die-offs are common in reservoirs (Sublette et al. 1990).