The largest of the winged oysters, reaching about 25 cm (10 in) - two to three times the size of the other species on the reef. The hinge is long and straight with a pronounced wing at the posterior end, the shell blackish brown outside, and the interior a broad sheet of nacre with a dark border. Young animals are thin and flexible at the margins; older ones thicken and grow heavy, and are usually well fouled with sponge and algae by then.
It attaches by strong byssal threads to gorgonians, black coral colonies, wreckage and other raised hard structure between about 5 and 30 m (16 and 100 ft), a habit that keeps it in the current where a filter feeder does best. Where the species is common elsewhere in the Indo-Pacific it is farmed for half-pearls, or mabé, grown against the inner shell rather than free in the tissue - the nacre is large-sheeted enough to make that practical. In the 🌊 Red Sea it turns up singly rather than in beds, most often on wrecks and deeper drop-offs.
- large, heavy wing oyster with a long straight hinge
- blackish shell with a broad pearly interior
- attached to gorgonians, black coral or wreckage
