Biochemical composition, reproductive activity and food availability of the lion's paw scallop Nodipecten subnodosus in the Laguna Ojo de Liebre, Baja California Sur, Mexico

摘要

The relationships between the nutrient storage cycle. reproductive activity. and available food for the lion's paw scallop Nodipecten subnodosus were investigated during a one-year period in Laguna Ojo de Liebre, Baja California Sur. Mexico. Based on histologic data this study showed that the reproductive cycle of N. subnodosus could be divided in four periods: (1) period of quiescence from December to March with a small reproductive activity in February-March, (2) period of initial reproductive activity from April to May, (3) period of maximum ripeness from June to September, and (4) period of spawning from September to November. The seasonal changes in biochemical composition of somatic tissues of N. subnodosus at this locality indicated a clear nutrient storage and use cycle related to reproductive activity. However, the biochemical reserves of adductor muscle, digestive gland, and mantle were used differently over time. Proteins and acylglycerides could be transferred from the testis portion to the ovary portion during the ripening process. We showed that gametogenesis in N. subnodosus from Laguna Ojo de Liebre relied on stored reserves, as a consequence of the low food quantity (maximum 1.2 mug L-1 chlorophyll a) and the low nutritional quality (maximum food index 17%) of the food available for suspension-feeders. The spawning of N. subnodosus in Laguna Ojo de Liebre coincided with the chlorophyll a maximum concentration so it appeared to be triggered mote by the phytoplankton abundance than by temperature.