Tridacna gigas: the giant clam:.........Giant clams are found throughout the Tropical Indo-Pacific oceanic region, from the south China seas in the north to the northern coasts of Australia and from the Nicobar Islands in the west to Fiji in the east. Giant clams occupy coral reef habitats, typically within 20 meters of the surface. This enormous shellfish is the largest species of bivalve mollusc in the fossil record, and the heaviest of all the living molluscs . Like all bivalve molluscs, the shell of the giant clam (Tridacna gigas) consists of two valves, although in the larger giant clams these cannot close completely). The shell is extremely thick and lacks bony plates; (taken while diving in the Maldives)