Littleneck clams have a chalky brownish-white shell that is marked by numerous strong radial and concentric ridges, and the umbo (hinge) is located anterior to the midline of the shell. The two equal-sized valves are oval or heart-shaped, and the shell seldom exceeds 6 cm in length (maximum shell length 7 cm). Littleneck clams commonly occur in the intertidal zone of Oregon estuaries, but they are also found in protected areas along the outer coast and in subtidal habitats down to a depth of 40 m. They typically inhabit coarse sand and fine gravel mixed with stones and mud where they dig themselves 3 to 8 cm below the surface and move horizontally through the soft sediments. They are suspension feeders that use their short siphons to feed on phytoplankton and organic materials close to the surface of sediments. In Oregon, littleneck clams spawn during the spring and summer seasons, and their planktotrophic veliger and pediveliger larvae remain in the water column for 3 to 4 weeks. Littleneck clams are the target for recreational fisheries, and adult clams are preyed upon by a wide diversity of predators, including diving ducks, raccoons, gastropods (e.g., Lewis’s moon snail, leafy hornmouth snail, etc.), octopi, sea stars, Dungeness crab, red rock crab, European green crab, and fishes (e.g., Pacific staghorn sculpin). Populations of littleneck clams have experienced broad declines across their geographic range in the Pacific Northwest (AK to CA) over the past three decades. The biogeographic range extends from Japan and the Siberian coast to the Aleutian Islands (AK) and Baja California (MX).
Overview
- Species Common Name Native littleneck clam
- Species Scientific Name Leukoma staminea
