The Site survey and the study on reproductive cycles of freshwater pearl mussels in the central part of Thailand

Abstract

Eight species of freshwater pearl mussels were collected from general canals and irrigation canals in Nakornsawan Province, Chainat Province, Lopburi Province, Saraburi Province, Sing buri Province, Ayutthaya Province and Pathumthani Province, from September 1988 to September 1989. Pilsbryochoncha exilis was the most abundant and distributed in all provinces surveyed. Ensidens ingallsianus, Uniandra contradens and Scabies crispata were found in the lesser extent. Pseudodon vondembuschianus was found only in Lopburi Province. The largest species which found in the deepest water was Hyriopsis (Limnoscopha) myersiana. The females with marsupia were observed from September 1988 to February 1989 and the patterns were quite different from each other. Fourteen species of fish were found as hosts of glochidium from mid-October 1988 to March 1989 which corresponded with the gestation and elimination of glochidium of female mussels.