1994 Fiscal Year Final Research Report Summary

Reproduction and recruitment of edible bivalves in tropical seagrass beds

Research Project

Project/Area Number	05660217
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	General fisheries
Research Institution	University of the Ryukyus
Principal Investigator	YAMAGUCHI Masachi Department of Mrine Sciences, University of the Ryukyus, 理学部, 教授 (50112446)
Project Period (FY)	1993 – 1994
Keywords	bivalve / seagrass bed / recruitment / reproduction / population / dynamics / Modiolus philippinarum / Anadara antiquata
Research Abstract	Reproductive activities of edible bivalves (Modiolus philippinarum and Anadara antiquata) lasted throughout summer months but were erratic, in a tropical seagrass bed at Kin Bay, Okinawa. Spat of M.philippinarum settled abundantly on spat-collectors but there was no A.antiquzta spat. The juveniles M.philippinarum disappeared from the spat-collectors after growing to a few millimeters. They probably resettled to adult microhabitat. There wer numerous species of larval molluscs in plankton samples collected in the seagrass bed area. However, most of those larvae were not idintifiable because early life-histories of tropical inshore molluscs are largely unknown. My repeated attmpts to artificially breed some of the dominant bivalves failed during the research period for two years. The seagrass bed at Kin Bay exhibited diverse and rich molluse fauna but the population densities of most species were very low.