Cementation in the freshwater bivalve family Corbiculidae (Mollusca : Bivalvia): a new genus and species from Lake Poso, Indonesia

A species from Lake Poso, Indonesia represents the first instance of cement ation in the freshwater bivalve family Corbiculidae. Posostrea anomioides g en. nov., sp. nov., which is cemented indifferently by its left or right va lve to calcareous rocks, reaches a size of 16 mm. It has typical corbiculoi d dentition, with serrated lateral teeth, and juveniles are brooded primari ly in the inner ctenidia. Lake Poso occupies a tectonic fault in central Su lawesi. Posostrea adds to an interesting radiation of endemic fishes and mo lluscs, including the gastropod genera Miratesta and Tylomelania.