Group of aquacultured angelwing clams. The angelwing clam, Cyrtopleura costata , is a large sand-burrowing clam in the Family Pholadidae. Its valves are generally equal in size and white in color, with shades of pink sometimes observed.
Body shape is oval and elongated, with narrowing of the posterior end.
Valves are patterned with radial riblets, which are sharp and angular in the anterior, and broader in the posterior. Inside the valves, behind the umbones, is a thick, winged plate that lies transverse to the plane of the valves. It is most common in the low intertidal zone, at or just below the low tide line, where it can burrow to a depth of approximately 3 feet in soft sand or muddy substrata . Gustafson et al. Upon settlement into soft sand or muddy substrata, juveniles burrow as much as 3 feet below the surface.