Atlantic Wing Oyster Shell,  Pteria colymbus

Atlantic Wing Oyster Shell, Pteria colymbus.  Shell collected off the beach at Akumal, Quintana Roo, March 2010. Size: 4.5 cm (1.75 inches) x 2.3 cm (0.9 inches). Collection, photograph and identification courtesy of Bob Hillis, Ivins, Utah.

Phylogeny: The Atlantic Wing Oyster, Pteria colymbus (Röding, 1798), is a bivalve member of the Pteriidae Family of Pearl Oysters or Wing Oyster Shells. The genus Pteria is one of only two genera in this family, and there are twenty-nine species in this genus. They are  also known as the Atlantic Wing-Oyster.

Description: The Atlantic Wing Oyster shell is  fairly flattened and P-shaped in outline. The long straight hinge can vary in length, but the posterior end usually extends several times longer than the anterior. The posterior margin is rounded, while the anterior is straight and sloped. The left valve is slightly larger and more inflated than the right. The exterior of the shell is sculpted by several straight ribs that run from the beak to the margin, crossing fine concentric growth rings. Some specimens display blunt spines. The exterior is brownish in color and is covered by a matted brown periostracum. The interior is gray or silver and iridescent.  Atlantic Wing Oysters reach a maximum of 9.0 cm (3.5 inches)  in length.

Habitat and Distribution:  Atlantic Wing Oysters use byssal threads to attach to gorgonians, sea fans, rocks, pilings and other hard objects live at depths between  3 m (10 feet) and 30 m (100 feet). They are a temperate to tropical Western Atlantic species that are found in all coastal Mexican waters of the Atlantic Ocean including the Gulf of Mexico and the Caribbean.

Ecology and Behavior:  Atlantic Wing Oysters are suspension feeders that feed primarily on planktonic algae and suspended organic matter. They are prey for crabs, fish, and  sea stars. They are gonochoric and reproduce sexually, through broadcast spawning, with external fertilization. Females can produce over 100 million eggs per year. There is no mention in the available literature of them engaging in any types of parasitic, commensal, or symbiotic relationships, though they do host algae and other ectobionts. From a conservation perspective they have not been formally evaluated however they are fairly common with a relatively wide distribution and should be consider to be of Least Concern.

Synonyms: Avicula cornea, Avicula jamaicensis, and Pinctada colymbus.