Flat bottom sea stars are very common in the Bering Sea north of the Alaska Peninsula and range in lesser numbers from the waters off British Columbia around the Pacific Rim to the Japanese archipelago. They grow to diameters of sixteen inches, with the typical five-armed bodies of most echinoderms. Flat bottom sea stars are foraging predators, feeding on crustaceans, though they have a curious relationship with the juvenile king crab, which nestle among their arms for protection. Like many other echinoderms, flat bottom sea stars can regenerate lost arms, which they will shed to escape predators such as large crab.