Spawning occurs as early as mid-February in Florida, as late as June-July in the St. Lawrence River; see Hill et al. (1989) for more detail on specific areas, and Crance (1984) for spawning in relation to temperature in various areas. Eggs hatch in about 2-3 days. Males usually become sexually mature in 1-3 years, females in 4-6 years (Middle Atlantic region). Spawning occurs in large aggregations (Moyle 1976).
See Hassler (1988) for a review of life history in Sacramento-San Joaquin Delta, California. See also Crance (1984).