Spawns as early as February-March in the south, April-May in Chesapeake Bay tributaries, May-July in north, at water temperatures of 13-21 C. Eggs hatch in about a week. Females first breed at about 11 years (mean) in South Carolina, 18-19 years in the Hudson River, about 27-28 years in the St. Lawrence River; generally matures at a younger age in the south than in the north (as early as 7 years or as late as 34 years). Successive spawnings may be separated by intervals of a few to several years. May live several decades. See Gilbert (1989) for much further information on reproduction.