They inhabit shallow waters of coral reefs in warm seas of the Indo-Pacific region.

In the Ancient Roman text Natural History, Pliny the Elder explained the nomenclature comes from the fact that "they are so large as to require three bites in eating them.”[4] The genus contains the following species:[5][6] An alternative older classification recognises a third subgenus Persikima containing T. derasa and T.

[9] Tridacna clams are common inhabitants of Indo-Pacific coral reef benthic communities in shallower waters.

Their large size and easy accessibility has caused overfishing and collapse of the natural stocks in many places and extirpation in some of the species.

[17][18] Over a hundred examples of carved Tridacna shells have been found in archaeological expeditions from Italy to the Near East.

Similar in artistic style, they were probably produced in the mid-seventh century, made or distributed from the southern coast of Phoenicia.