Gonadal Development, Reproductive Cycle, and Biochemical Composition of the Siphon Clam <i>Panopea globosa</i> (Bivalvia: Adapedonta) in the Southeast Gulf of California, Mexico

The reproductive dynamics of Panopea globosa in Southeast Gulf of California (GC) was investigated (April 2014 to April 2015). The temperature, salinity, chlorophyll a , organic, and inorganic seston of the water were obtained every month. A total of 195 clams (15/month) were collected from the Altata‐Ensenada Pabellones lagoon system (Sinaloa, Mexico) and analyzed using conventional histological and biochemical techniques to study their gametogenesis, reproductive cycle, and biochemical composition. Five phases of gametogenic development were identified and described in both sexes. Males presented mature gonads in October−December, while females in November, with spawning for both sexes in December. Of the total clams sampled, 44.62% were males, 45.13% females, and 10.26% hermaphrodites; the sexual ratio was 0.99M:1F. Oocyte diameter was positively correlated with the ripe and partially spawned phases. The nutrient dynamics between organs and the variation in oocyte diameter presented a pattern corresponding to the development of the gametogenic cycle. Results of this study suggest a reproductive season of P. globosa from October to January in the area, being different from those reported in other localities within the GC.