Often referred to as the true giant clam (because it is the largest species of tridacnids), T. gigas has 4 to 5 distinct ribs, which do not have scutes, and its shell is asymmetrical in form. The upper margin is strongly curved, with finger-like projections (most especially prominent in juveniles). The clam's incurrent siphon lacks tentacles. This species can grow to approximately 135cm in length.
While this species is native to Philippine waters, this specimen exists in a giant clam sanctuary.