The Atlantic Wing Oyster, Pteria colymbus (Röding, 1798), gets its common name from the expansions on its shell, which are technically known as auricles. Atlantic Wing Oysters are commonly found living in association with Sea Whips and other gorgonians, to which they attach using a bundle of fibers called the byssus. Its shell may grow to about 2–2.5 inches. Shells are brownish, with rays of lighter color. The shell on young individuals shows auricles that are relatively larger than those of adult shells. Wing Oysters and Pearl Oysters are members of the family Pteriidae, and are not closely related to true (edible) Oysters.
Atlantic Wing Oyster shells, Pteria colymbus. The two valves on left are from an adult shell from Sanibel, the shell on the right was found attached to a gorgonian on Captiva. Photos by José H. Leal.