Species richness of bivalves and gastropods in Iwahig River-Estuary, Palawan, the Philippines

Abstract

Iwahig River-Estuary in Palawan, Philippines is one of the least disturbed river-estuary systems where biodiversity remains undocumented. In this study, the molluscan fauna of Iwahig River-Estuary is based on samples taken from three site groups: mangrove forest, lower reaches of the river, and intertidal flat near the river mouth. We have listed a total of 15 bivalves and 50 gastropods species spread over among 25 families and 45 genera. Some of these species are habitat specific while others overlap across study sites. Among the recorded species Nassarius pullus and Anadara uropigimelana had the widest range of distribution occurring in mangrove forest, river bed, and intertidal flats thereby considered as a potential biological indicator for climate change adaptation and mitigation studies. Commercially exploited species for food and local shell craft industry include nine bivalves and two gastropods. Some other species have the potentials for aquaculture and shell trade. Exploring the potentials of these species as source of sustainable income for the locals is suggested.