Gonad rematuration and reproductive cycle of the mud clam Anodontia edentula in Guimaras, Central Philippines

Anodondia edentula locally known as imbao bayi is a commercially important mud clam harvested for human consumption in Central Philippines. Since it is used as a source of food and livelihood to the local gleaners, it was observed that fewer and smaller mud clams have been harvested. Thus, regulating proper collection of this organism and a sound knowledge of its reproductive cycle are necessary. This study aimed to describe some aspects of the reproductive biology of A. edentula. Fifty mud clams were collected and dissected every month. Monthly monitoring of the gonadosomatic index in the study shows that A. edentula spawns throughout the year. Under laboratory condition, male has shorter gonadal rematuration than females. Spent male A. edentula that spawned will spawn again after three weeks through serotonin injection while females will spawn gain after six weeks as long as intrinsic and extrinsic factors are met. This type of maturation schedule suggests continuous reproductive competence. Higher spawning rate is obtained in clams reared with mud substrate than without mud substrate , but the survival rate was found to be higher for clam reared without mud substrate than with mud substrate. Results of this study provide useful information for the management and aquaculture of this bivalve species.Keywords: Biology, gonad rematuration, reproductive cycle, Anodontia edentula, gonadosomaticindex, gonadal rematuration, serotonin, spawning, mud substrate, experimentaldesign, Guimaras, Central Philippines