Tridacna gigas
Diagnosis
This is the largest living bivalve mollusk. The shell may reach up to 1.5 meters in length. They are characterized by having 4 to 5 large, inward facing triangular projections of the shell aperture, thick, heavy shells without scutes (juveniles may have some scutes), and an inhalent siphon with no tentacles. The mantle is usually golden brown, yellow, or green, with many irridescent blue, purple, or green spots, especially around the mantle edges. Larger individuals may have so many of these spots that the mantle appears solid blue or purple. Giant clams also have many pale or clear spots on the mantle, referred to as 'windows'. Giant clams cannot completely close their shell once fully grown.