GAMETOGENESIS OF MERCENARIA-MERCENARIA, M-CAMPECHIENSIS AND THEIR HYBRIDS

Non-native stocks of Mercenaria mercenaria, M. campechiensis and their reciprocal hybrids were cultured in South Carolina. Histological exam ination of the gonads revealed a bimodal gametogenic pattern with a ma jor spring spawning peak that continued into summer, followed by a sma ller spawning peak in fall. The spring spawning peak of M. mercenaria and its maternal hybrid occurred one month earlier than that of M. cam pechiensis and its maternal hybrid. The length of the spring spawning peaks of the hybrids were two months shorter and less intense than tho se observed for M. mercenaria or M. campechiensis.