Wing Oyster

Overview

The Wing Oyster (Pteria hirundo) is a distinctive marine bivalve mollusk recognized by its thin, elongated shell that resembles a pair of outstretched wings. It is a medium-sized species that plays an important ecological role as a filter feeder, helping to maintain water quality by consuming plankton and suspended particles.

Distribution & habitat

This species is native to the Eastern Atlantic Ocean, ranging from the British Isles south to Angola, and is also found throughout the Mediterranean Sea. While it can inhabit shallow waters, it is often found at greater depths, sometimes reaching over 500 meters. It is an epizoic species, meaning it attaches itself to various substrates, including rocks, artificial structures, and other marine organisms like gorgonians, black corals, and sea urchins, using a strong byssus.

Appearance

The shell is strongly inequilateral, typically measuring 60–70 mm in length, though it can occasionally exceed 100 mm. It is thin, fragile, and flattened, with a straight hinge line that extends into asymmetrical projections. The exterior is generally brown with darker radial bands and may feature irregular, flat scales. The interior is lined with a brilliant, mother-of-pearl nacre. Often, the outer surface is obscured by various epibionts, such as bryozoans, hydroids, and polychaetes, that grow on the shell.

Biology & behavior

Pteria hirundo is a slow-growing species with a lifespan that can exceed 15 years. It reaches sexual maturity at approximately two years of age. Reproduction is believed to occur during the summer months, with small juveniles appearing in late summer. As a filter feeder, it is susceptible to environmental changes, including fluctuations in water quality and habitat loss.