Storage and reproductive strategy in Crassostrea gigas from two different growing areas (Normandy and the Atlantic coast, France)

The reproductive cycle of the Pacific oyster (Crassostrea gigas) is compared in two different areas (Saint-Vaast la Hougue, Normandy, and Marennes-Oleron, Charentes). Major differences were observed with respect to the success of spawning: although the general course of gametogenesis appeared to be similar, gonial mitoses were delayed on the Normandy shore and the timing of the subsequent expansion of gonadal tubules was different. However, spawning time was the same in both areas. This spawning was massive in Atlantic oysters and only partial in Normandy oysters. Storage tissue development in the gonadal area was also investigated and related to the process of gametogenesis.