태화강 하구에 서식하는 바지락, Ruditapes philippinarum (Bivalve: Veneridae)의 연생식주기

Abstract

The annual reproductive cycle of Ruditapes philippinarum (Bivalve: Veneridae) was studied by histological study and fatness index. Samples were collected monthly in estuary of Taehwa river from April 2006 to March 2007. Gonadal phases can be divided into six stages; early active stage, late active stage, ripe stage, spawned stage, degenerative stage, inactive stage. Examination of histological preparation showed that gonadal development began in April and spawned from August to October. The lowest water temperature was in March (8.0℃) and the highest temperature was in August (29℃). From June to October when the water temperature went above 19℃ R. philippinarum began riping and spawning. Therefore the development of the gonad was closely related to the water temperature. and fatness index(=MW×100/SL3). The monthly variations in the fatness index closely related to reproductive cycle. The fatness index reached at the highest value in June (0.0694) and decreased during degenerative stage and inactive stage. In this study, most specimens were diecious in sex but three individuals showed hermaphroditism.