Developmental Stage of the Gonad of the Clam Paphia (Paratapes) undulata

By observing the seasonal changes of gonad of live shellfish and the changes of gonad on histological sections,the yearly development of the gonad of the clam Paphia (Paratapes) undulata (Born) in the sea area of Beihai, Guanxi was studied.Taking the developmental status of the gametes in follicles as the main characteristics,the authors thought that the development of the gonad could be devided into six stages for both male and female,ie,resting stage,proliferating stage,growing stage,maturing stage,spawaing stage,and degenerating stage.Meantime,it was revealed that the gonadal development of the clam has only one cycle in a year in Beihai area. In addition, some precocity were found.