Southwest Florida Shells
by José H. Leal
Family Plicatulidae
Plicatula gibbosa
(Lamarck, 1801)
Atlantic Kitten Paw
Shell size to 26 mm; shell fan-shaped, thick. Sculpture of 5-7 rounded ribs impart zigzag aspect to shell margin. Hinge with pair of strong teeth. Color cream to white with many fine, concentric, reddish lines. Surface of ribs of darker color. The species is commonly found on the beaches of Southwest Florida (and along the entire coast of the Sunshine State). It is not unusual for one to find complete shells (paired valves) of this species. Sometimes it is very difficult to separate the valves of a complete shell, not only because they are naturally very well adjusted to each other, but also because the shells may get cemented together by after-death incrustations and calcareous growth. The well-defined pleats on the shell give strength against crushing by predators, and also help prevent the valves from separating under stress. The species belongs in the Plicatulidae, a small bivalve family with only about 16 species worldwide.