Shell of the giant clam (Tridacna gigas), one of the many species of clams belonging to the genus Tridacna. They are the largest living bivalve mollusks known and live in warm and shallow marine environments amidst coral reefs. They can measure up to 120 cm, weighing up to 200 kilograms. They are an endangered species, mainly on account of their fame as a culinary delicacy.