전자저널 > 전자저널 > Reproductive Ecology and Parasite of the Venus Clam, Cyclina sinensis (Gmelin), on the West Coast of Korea 1. Reproductive Ecology

Reproductive Ecology and Parasite of the Venus Clam, Cyclina sinensis (Gmelin), on the West Coast of Korea 1. Reproductive Ecology

Yong Ho Kim, Ee-Yung Chung and Young Gill Kim

School of Marine Life Science, College of Marine Science and Technology, Kunsan National University, Kunsan 573-701, Korea

We investigated the gonad index (GI), gonadal development, the reprodutive cycle and first sexual maturity of the venus clam, Cyclina sinensis by histological observations. Samples were collected from the intertidal zone of Komso Bay, Chollabuk-do, west coast of Korea, from April 1998 to March 1999. This clam is dioecious and oviparous. Monthly changes in the gonad index (GI) showed a similar pattern to the reproductive cycle. Ripe oocytes are about 90-100 μm in diameter. The spawning period was between early July to September, and the main spawning occurred between July and August when the sea water temperature was over 20℃. The reproductive cycle of this species can be divided into five successive stages: early active stage (February to April), late active stage (March to June), ripe stage (April to August), partially spawned stage (July to October), and spent / inactive stage (September to February). Percentages of first sexual maturity of female and male clams measuring 26.1-30.0 mm in shell length were 53.3% and 62.5%, respectively, and 100% for the clams > 41.0 mm. It is assumed that both sexes begin reproduction at about two years age.

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