Permalink : http://hdl.handle.net/2115/52319

KEYWORDS : Red tide;Heterocapsa circularisquama;Population dynamics;Maizuru Bay;Indirect fluorescent antibody technique

The noxious dinoflagellate Heterocapsa circularisquama is the most harmful species to bivalves such as oysters, Manila clams, and pearl oysters due to causing mass mortalities of these bivalves by the red tides in coastal areas of Japan. The population dynamics of H. circularisquama was monitored in Maizuru Bay, Kyoto Prefecture, in 1999 to 2001 with the indirect fluorescent antibody technique (IFAT) using monoclonal antibodies, which enable the species-specific detection of this species with high sensitivity detecting even at low cell densities of several cells L-1. H. circularisquama cells were successfully monitored, and they appeared in late spring, showed maximal level in the summer and disappeared in autumn, resembling the results obtained in Ago Bay of Mie Prefecture. The water temperature is considered to be the most important factor limiting the distribution of H. circularisquama.