Some ecophysiological information on Geloina expansa (Bivalvia: Cyrenidae) population in Santiago River, northern Philippines: prelude to aquaculture technique development

Knowledge on the optimum environmental conditions for a potential aquaculture species is necessary to simulate an artificial setting. The current study investigated the influence of several environmental parameters on the physiology of the mud clam Geloina expansa under natural condition. Highest CIs were recorded during the months of May to August, averaging to 179.79 (±6.47 SE) while the rest of the months averaged only 158.53 (±2.68). Geloina expansa population monthly GSI in Santiago River ranged from 9.64 to 26.51, low values were observed from November to February (12.00±0.36) and from June to July (12.24±2.59). Chlorophyll a concentration and sediment TOM have significant influence in CI variations. DO significantly affected the changes in GSI. These ecophysiological information are vital for the development of aquaculture techniques for G. expansa in northern Philippines.