Biomodal spawning peaks, as determined by the gonadosomatic index, were noted for the spotted seatrout (Cynoscion nebulosus) in the Barataria Bay, Louisiana, system for 1976 and 1978. Males matured earlier in the season and at a smaller size than females. Males were found to have sound producing capabilities. Fish spawned throughout the bay regardless of water depth or substrate. Spawning seemed to occur in the northern portion of the bay later than in the southern portion. Photoperiod and temperature were the only exogenous factors found to have a direct relationship with spawning.