Reproductive cycle and releasing time for increase of resource of adult sea cucumber Apostichopus japonicus released to seed breeding grounds

ABSTRACTThe reproductive cycle and releasing time for effective increase of resource of adult sea cucumber (Apostichopus japonicus) have been studied in the west coast of Korea. Adult sea cucumbers collected in Seocheon-gun April 2013 for first release and in the uncontaminated Taean-gun area in the west coast of Korea. Divers monthly collected the specimens in the released area from December 2013 to November 2014 in order to investigate the reproductive cycle of A. japonicas in Taean-gun. Random specimens were dissected to examine the gonadal developmental stages and discharge rates of the guts and gonads. The reproductive cycle of A. japonicus in both sexes are classified into the following six successive stages in the Taean-gun: (1) Stage I (recovery stage from December to February), (2) Stage II (early growing stage from February to March), (3) Stage III (late growing stage from March to April), (4) Stage IV (mature stage from April to July), (5) Stage V (partly spawned stage in July), and (6) Stage V...