전자저널 > 전자저널 > Reproductive Cycle of Sulf clam, Coecella chinensis (Mesodesmatidae: Bivalvia)

Reproductive Cycle of Sulf clam, Coecella chinensis (Mesodesmatidae: Bivalvia)

Jin Hee Kim, Min Ho Son, Hee-Woong Kang and Ki-Young Lee

Marine Eco-Technology Institute, Busan 608-830, Korea West Sea Fisheries Research Institute, NFRDI, Incheon 400-420, Korea Department of Marine Biotechnology, Kunsan National University, Gunsan 573-701, Korea

The reproductive cycle, gonad index, condition index, and the sex ratio in female and male Coecella chinensis,which were collected from the coastal waters of Namhae, the South Coast of Korea, were investigated byhistological analysis and morphometric data. Monthly variations of the gonad index and condition index of thisspecies showed similar patterns to that of the reproductive cycle. The reproductive cycle in female and male C.chinensis can be classified into six successive stages: early active stage (April), late active stage (May), ripe stage(June), partially spawned/spent stage (June to August), degeneration stage (August) and inactive stage(September to March). According to monthly changes in relative frequency distributions of ovarian egg diametersof this species, in particular, a number of ripe eggs ranging about 70 μm appear in June, however, in July andAugust, although the mode of egg diameters ranging about 50 μm appear about 80%, these ripe eggs rangingfrom 60 μm to 70 μm are gradually decreased during the period from June to August. Therefore, the spawningperiod of this species is continued from June to August with a peak between July and August when the seawatertemperature exceeds about 24.5°C. The sex ratio of female and male individuals was not significantly differentfrom 1:1 (χ2 = 1.20, p > 0.05). No hermaphrodites were found.

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