Range/Geographical Distribution: North Carolina to Florida and the West Indies.
Habitat: Shallow waters with sandy or muddy bottoms.
Description: Large bivalve with a thin, fragile, wedge-shaped shell that is yellow/brown or purple/black.
Size: Can reach one foot in length.
Food: Filter feeder; eats plankton and detritus.
Predators: Whelks and crabs.
Conservation Status: No legal status.
Interesting Facts: The byssal threads—which hold a pen shell in place in the sand or mud—of a Mediterranean species of pen shell were once used by humans to weave garments such as gloves. The mussels of pen shells are sold as “scallops” in some markets.
On the Coast: Pen shells commonly wash up on Georgia’s beaches but are rarely whole.