Reproductive cycles of Anadara granosa L. in Jebilung Satun Province
1990
Suwanjarat, J. (Prince of Songkhla Univ. Hatyai Campus, Songkhla (Thailand). Faculty of Science. Dept. of Biology) | Supattra Parnrong
Reproductive cycles of cockles (Anadara granosa L.) from Jebilung, Satun Province were studied by means of histological examination. Monthly samples with an average length of 3.38 cm were collected from March 1989 through March 1990. Gametogenic activity took place throughout the year with a spawning period coresponded with monsoon season from August through January. The peak of the spawning period was in November. The two periods of intense sprawning activity in female cockles were found in August and November, while spawning in male cockles occurred throughout the breeding season. The gonad index value indicated that the highest gonad maturation appeared in September. The sex ratio of female was greater than male (1:0.6). There was no evidence of hermaphrodism in all adult cockles during the entire period of this study.
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