This delicate bivalve of otherworldly beauty is aptly named the « Angel Wing », and has attracted the adoration and fascination of shell collectors for hundreds of years. Each thin and almost translucent wing-like valves carry 24-27 strong radial ribs which carry numerous beads that convincingly look like feathers on the wing. It has a rather wide distribution range from Massachusetts, USA to as far south as Brazil, although vast majority of specimens on the market originate from Florida, USA. A large filter-feeding pholadid inhabiting muddy bottoms of very shallow water down to about -5m in depth, it is most common in intertidal waters just below the low-water mark and usually burrow deep into the mud, up to about a metre. The animal is bulky with a powerful foot as well as a hefty fused siphon which is so large that the two valves cannot be closed and instead permanently gape apart when alive. Each valve carry on the inside a apophysis, spoon-like appendage which is a point of attachment for the foot musculature. As usual for the genus Cyrtopleura it has a small butterfly-like mesoplax and also a large, entirely corneous protoplax (both shown) but lacks a metaplax. These accessory plates help cover part of the animal which would be exposed otherwise, due to the large gape in its valves, and is a comm.on feature for members of the famly Pholadidae. When alive both valves are covered by a thin, brown periostracum which is often worn near the umbo. Although it is a comm.on species, large specimens with both the mesoplax and especially the protoplax preserved are very difficult to acquire. Separated single valves are comm.only washed ashore on beaches and is a beachcomber's favourite. Typical shell length around 130mm., extremely large specimens may reach 200mm. Its meat is edible and in Mexico, Cuba, and Puerto Rico it is harvested comm.ercially for food and supports important fisheries. Aquacultural research has shown that it is a fast growing species and reaches 50-70mm. shell lenth within six months of settlement.