Atlantic Surf Clam (also known as Bar Clam, Skimmer Clam)
Phylum: Mollusca, Class: Bivalvia, Order: Cardiida, Family: Mactridae, Genus: Spisula, Species: Spisula solidissima · Mactridae (Trough shell family) · Bivalve, whole shell, oval to triangular shape
Species
Spisula solidissima
Shell Type
Bivalve, whole shell, oval to triangular shape
Family
Mactridae (Trough shell family)
Size
Approximately 4 to 6 inches, which is average for this species. Adults typically range from 4 to 8 inches.
Color & Pattern
The exterior ranges from dull white to yellowish-tan, often with a thin brownish periostracum on live specimens that erodes on beach-worn shells. The interior is a smooth, chalky white with a prominent hinge plate.
Rarity
Very Common
Habitat
Found in high-energy surf zones and shallow subtidal waters down to about 130 feet, buried in sandy substrates.
Geographic Range
Western Atlantic from the Gulf of St. Lawrence in Canada south to Cape Hatteras, North Carolina, and sometimes further south into the Carolinas.
Description
A large, robust, triangular-to-oval bivalve with smooth concentric growth lines. The shell features a sturdy hinge with well-developed cardinal and lateral teeth, designed to withstand crashing surf.
Key Features
Large size, heavy and solid construction, distinct triangular-oval shape, and prominent internal hinge pit (resilifer) characteristic of the Mactridae family.
Collector Value
Very low commercial value due to high abundance, but a staple collection piece for beachcombers along the Atlantic coast.
Condition Notes
The shells shown in the pile are mostly beach-worn, sun-bleached white specimens, some with natural weathering and minor edge wear. Condition ranges from Good to Fair for individual loose valves.
Interesting Facts
The Atlantic Surf Clam is commercially harvested for human consumption, primarily for clam strips and chowder. They can live up to 30 years and use a muscular foot to rapidly burrow into the sand.
Ecological Role
Serves as a major prey item for sea stars, whelks, gulls, and bottom-feeding fish. Filter feeders that help maintain water clarity.
Similar Species
Stout Tagelus (Tagelus plebeius) or Surf Scallop, though the solid triangular shape of Spisula solidissima is distinct.
Beach Finding Tips
Look along high-energy Atlantic sandy beaches, especially after storms or winter nor'easters at low tide.
Notes
Outer banks, North Carolina on Kill Devils Hill beach