Biology/Natural History: Spawns late spring and summer. In Washington spawning is simultaneous (the same day) along several kilometers of beach, triggered by a sudden rise in water temperature to about 13C (usually in late May or June). Intensity of spawning varies dramatically from year to year. In Alaska they spawn every year, but not simultaneously, in July and August. Larvae are pelagic for about 8 weeks. Live about 12 years in Washington. This species is frequently dug by humans for food, but as with most species on the open coast, is susceptible to paralytic shellfish poisoning (PSP, toxic to humans) due to ingesting too many dinoflagellates such as Gonyaulax during the summer. The animal typically remains just below the surface, with a dimple in the sand above the siphon. When disturbed, for example by human footsteps approaching, it begins digging rapidly. Predators include flatfish such as the starry flounder and the Dungeness crab Cancer magister. May have a commensal nemertean worm, Malacobdella grossa, or the pea crab Pinnixia faba in its mantle cavity.
These clams are called razor clams for a reason. If while a clam digger grasps the ventral side of the shell in the rush to catch up with the rapidly-digging clam, he may pay for it with a deeply cut hand. Fortunately, the clams always orient with the hinge toward the ocean so if a digger will always reach into the hole on the oceanward side he will be safe from cuts (but will still have to dig fast!)