Pacific Littleneck Clam (also known as the Common Littleneck or Rock Cockle)
Phylum: Mollusca, Class: Bivalvia, Order: Venerida, Family: Veneridae, Genus: Leukoma, Species: Leukoma staminea · Veneridae (Venus Clam family) · Bivalve (two-shelled clam), whole shell, ovate to subquadrate shape
Species
Leukoma staminea
Shell Type
Bivalve (two-shelled clam), whole shell, ovate to subquadrate shape
Family
Veneridae (Venus Clam family)
Size
Approximately 1.5 to 2 inches in length, which is a very typical and mature size for this species. Adults generally range from 1.5 to 2.5 inches.
Color & Pattern
Displays a lustrous dark grey, charcoal, and bluish-grey base coloration with fine, intricate concentric growth lines and radiating ribs that create a checkered or patterned texture. The luster shows a natural sub-metallic sheen due to environmental polishing or mineral staining.
Rarity
Very Common, frequently found while beachcombing or clamming along the Pacific Northwest coast.
Habitat
Found in intertidal and shallow subtidal zones down to about 40 feet. Prefers protected bays, estuaries, and mixed substrates of gravel, sand, mud, and sometimes rocky areas where it burrows just beneath the surface.
Geographic Range
Northeastern Pacific Ocean, ranging from the Aleutian Islands in Alaska down to San Quintin, Baja California in Mexico.
Description
A robust, solid, rounded-oval bivalve shell with prominent, closely spaced concentric ridges crossed by fine radiating ribs, creating a distinct crisscross or lattice-like texture. The exterior exhibits smooth weathering highlights, while the robust shape is designed to withstand wave action in rocky or gravelly environments.
Key Features
Distinctive lattice pattern formed by prominent concentric ridges intersecting with fine radial ribs; oval to subcircular outline; prominent, slightly anteriorly turned beaks (umbones).
Collector Value
Low to Moderate commercial value as an individual specimen since they are very common, but highly valued by beachcombers and local collectors. Typically found easily in nature rather than purchased in specialty shops.
Condition Notes
Good to Fine condition. The shell is intact with strong structural integrity, though it shows natural weathering and wear consistent with wave action and beach tumbling. Colors and structural ribs remain well-defined.
Interesting Facts
Pacific littlenecks are highly valued in commercial and recreational fisheries and are often harvested for seafood. They are filter feeders that play an active role in cleaning coastal waters and are capable of burrowing up to 6 inches deep in the sediment.
Ecological Role
Serves as an essential prey species for sea otters, shorebirds, crabs, and fish. As a suspension feeder, it helps filter phytoplankton and organic particles, contributing to coastal water clarity.
Similar Species
Manila Clam (Venerupis philippinarum), which has a more elongated shell and smoother posterior margin, and the Native Butter Clam (Saxidomus gigantea), which lacks the prominent radiating ribs of the littleneck.
Beach Finding Tips
Look in protected gravelly or sandy beaches during low tide. Search near rocks or beds of eelgrass where sediment mixes with small pebbles, and look for small siphon holes or slightly disturbed substrate.