Gametogenic cycle of the transplanted-cultured pearl oyster, Pinctada fucata martensii (Bivalvia: Pteriidae) in Korea

The gonadal development and gametogenic cycle of transplanted-cultured pearl oyster, Pinctada fucata martensii, were investigated using individuals collected monthly from Tong-Young along the south coast of Korea from October 2000 to September 2001. The result of monthly change of condition index was similar to tissue weight rate. The highest value was observed in June and the lowest value was observed in November. The gonad of the pearl oyster was located around the digestive diverticula. The ripe testis was milky white while the ovary was light brown. The spawning period of the pearl oyster extended from April to August, with a peak between June and July. The gametogenic cycle could be classified into five successive stages: multiplicative stage (November to February), growing stage (January to March), mature stage (March and April), spawning stage (April to August) and resting stage (September to November).