About Pteria colymbus (Röding, 1798)
Pteria colymbus, commonly called the Atlantic winged oyster, grows to approximately 7 centimetres (2.8 inches) long and has a distinctively asymmetric shape. It features a long straight hinge, where one auricle (wing) extends far outward, while the other is much smaller. The upper valve is brownish, often mottled with paler markings. The lower valve is flatter and smaller than the upper, and the interior of the shell is pearly grey. The posterior margin of the shell is rounded, while the anterior margin is elongated and slopes at an acute angle to the hinge. A number of indistinct, irregular ribs flare out from the umbo. These ribs are sparsely covered with blunt spines, and the shell surface also has fine sculpturing made up of concentric growth lines. This species occurs in the Western Atlantic Ocean, at depths ranging from 3 to 30 metres (10 to 100 feet). Its geographic range extends from North Carolina and Florida, southward through the Caribbean Sea and the Gulf of Mexico to Venezuela and northern Brazil.
