Pacific Littleneck Clam

Like other members of Veneridae, this species has a chalky shell, the umbo being anterior to the midline of the shell, but closer to the midline than to the anterior end of the shell. The two equal-sized valves are oval or heart-shaped. The width of the shell is greater than a quarter of its length, and the shell seldom exceeds 6 cm (2.4 in) in length. The umbones point towards the anterior end of the shell. The hinge has three cardinal teeth in each valve, and a row of small teeth along the ventral margins of the valves. There are numerous concentric ridges, more clearly demarcked at the anterior end, but the radial ridges are often more clearly sculpted. The foot is large and there is a clearcut pallial sinus.

Leukoma staminea is native to the eastern Pacific Ocean. Its range extends along the coasts of North America from the Aleutian Islands and Alaska in the north to Baja California in the south. It usually occurs in protected areas on sand, hard mud and clayey-gravel substrates from the mid and lower shore down to depths of about 10 m (33 ft), usually buried less than 8 cm (3 in) beneath the surface of the sediment. Occasionally it is in more exposed locations, in gravel-filled cracks in rocks or in empty burrows of other clams.

This clam is a filter feeder and consumes microscopic algae such as dinoflagellates, diatoms, and cyanobacteria. Some dinoflagellates produce neurotoxins, such as saxitoxin and its derivates, that bioaccumulate in the clams and other bivalve mollusks and can cause paralytic shellfish poisoning (PSP) when the clams are eaten. Despite this fact, the clam was eaten by Native Americans and is still used as a food for humans. According to a 1996 report from the Marine Advisory Program at the University of Alaska, the United States Food and Drug Administration (FDA) considers seafood unsafe if it contains more than 80 μg of PSP-causing toxins per 100 g of tissue of the seafood. PSP is caused by a mixture of at least 21 different chemical species, some of which undergo chemical transformations within the dinoflagellates or within the animals that acquire the saxitoxins, and which are retained by different animals for different lengths of time. It is clear that PSP-causing toxin levels are typically much higher in the summer months though this does not mean the seafood is necessarily safe at other times. …