Biodiversity of Bivalves in South Bintan Waters, Riau Archipelago, Indonesia

Bivalves is the second most diverse group of molluscs after gastropods, they are also one of the most important members in marine ecosystems. Their taxonomic classifications are based on their morphology which tend to represent adaptation responses to ecology. The samples of bivalves examined in this study were taken in the South Bintan waters by Marine Geological Research and Development Center, Bandung. Identification of the bivalves shell samples was with the aid of a microscope and NIS-Elements software and identified using an identification book. There were 34 species of bivalves found in South Bintan Waters belong to 14 families. The highest abundance was in Station 1 the location close to the overflow of the river and a harbor (1162.5 ind.m-2) and the lowest was in Station 10 the location Station 10 the location close to a small island which is usually used as a tourist spot (62.5 ind.m-2). Their diversity and eveness index were included in the medium category with H’ value of 0.58-4.12 and e value of 0.11-0.89 respectively. There was species dominance in Station 3 (Liralucina lyngei of Lucinidae) and 10 (Cardites bicolor of Carditidae) but not in other stations. Both species was the most frequent species. Bivalves in South Bintan waters showed many different morphologies which represented their adaptation. The bivalve shells found were of different morphology. There are several forms of bivalve shell morphology that have shape round like species Chama japonica, triangular like species Gemma gemma, fragile like species Dendostrea rosacea. The shell decorations found in the bintan Bivalves samples are Spinose, Commarginally, Commarginally and radially ribbed. The hinge teeth are heteroodont, isodont, and schizodont.