Campeche Angel Wing
Pholas campechiensis Gmelin, 1791
In the lower photo, the twelve supporting ribs are clearly visible in the broken, discolored specimen.
A distinguishing feature of the Campeche Angel Wing shell is the approximately 12 supporting vertical partitions which protrude beyond the beak; underneath the beak is an elongate, spoon-shaped projection. The bivalve is narrow and about 4 inches long at maturity. The surface is white with distinct ridges over it, perhaps reminiscent of the feathers in an angel's wing. The ridges are more rasp-like on the anterior end (near the beak).
This shell is similar to the Angel Wing, Crytopleura costata, but the Campeche is a bit slimmer and smaller, and the sculptured pattern of ridges on its surface are more subtle than those of Crytopleura costata.
This very pretty clamshell, which lives offshore in the mud, may wash up from North Carolina to the Gulf, and from the West Indies to Brazil. Though the shell looks fragile, the mollusk is strong enough to bore through wood, coral, and even moderately hard rock.