Pacific Littleneck Clam (also known as native littleneck, rock clam, or steamer)
Phylum: Mollusca, Class: Bivalvia, Order: Venerida, Family: Veneridae, Genus: Protothaca, Species: Protothaca staminea · Veneridae (Venus Clam family) · Bivalve (two-shelled clam), whole single valve, oval to rounded-triangular fan shape
Species
Protothaca staminea
Shell Type
Bivalve (two-shelled clam), whole single valve, oval to rounded-triangular fan shape
Family
Veneridae (Venus Clam family)
Size
Approximately 2 to 2.5 inches in length based on scale context. This is a medium-sized adult specimen, as typical adults range from 1.5 to 3 inches.
Color & Pattern
Chalky white exterior surface due to weathering and sun-bleaching, though live specimens typically exhibit a yellowish-gray to brownish color with intricate darker zigzag patterns or brown rays. The interior is smooth and white, sometimes with a purple tinge near the siphon area.
Rarity
Very Common, frequently encountered by beachcombers and tidepoolers along the Pacific Northwest coast.
Habitat
Found in intertidal and shallow subtidal zones down to about 30 feet, buried a few inches deep in protected bays and estuaries. Prefers mixed substrates of sand, gravel, mud, and small rocks.
Geographic Range
Northeast Pacific Ocean, ranging from the Aleutian Islands in Alaska down to San Quintin, Baja California, Mexico.
Description
A sturdy, robust bivalve shell characterized by a strong, rounded-oval contour featuring prominent, concentric growth ridges crisscrossed by fine radial ribs, creating a distinct, tactile checkered or grid-like texture across the exterior surface. The margins are interlocking and finely crenulated along the inner edge.
Key Features
Distinguished by the combination of prominent concentric ridges crossed by fine radial ribs creating a distinct crisscross pattern, a strong oval-triangular shape, and a deeply impressed lunule near the umbo.
Collector Value
Low to Moderate commercial value as a collector specimen due to commonness, but highly valued for crafts, educational purposes, and beachcombing displays. Pristine live-taken specimens with patterns command slightly more, but weathered single valves have minimal monetary value.
Condition Notes
Fair to Good condition. The specimen is a single intact valve that is completely sun-bleached and weathered to a chalky white, having lost its original brown patterning. Minor surface wear and a small natural indentation or minor damage spot are visible, but the structural integrity of the valve remains sound.
Interesting Facts
Pacific littlenecks are an important culturally harvested seafood for Indigenous peoples of the Pacific Northwest and continue to be a popular target for recreational and commercial clam diggers. They are filter feeders that play a crucial role in maintaining water clarity in coastal estuaries.
Ecological Role
Serves as a primary filter feeder consuming phytoplankton, helping to clean coastal waters. Acts as a vital food source for various predators including sea otters, shorebirds, crabs, and diving ducks. Generally abundant with stable populations managed via sustainable harvesting regulations.
Similar Species
Manila Clam (Venerupis philippinarum), which is more elongated with less prominent radial ribs; and the Butter Clam (Saxidomus gigantea), which lacks the distinct grid-like radial ribbing and has smoother concentric growth lines.
Beach Finding Tips
Look along gravelly and mixed sand-mud beaches in the Pacific Northwest, especially near protected bays and estuaries during extremely low tides. Search just beneath the surface near small show holes left by the clam's siphons.