Pisaster

thumb|left|Ochre sea star at low tide, [[Saltspring Island, British Columbia]]

Pisaster (from Greek ', "pea", and ', "star") is a genus of Pacific sea stars that includes three species, P. brevispinus, P. giganteus, and P. ochraceus. Their range extends along the Pacific coast from Alaska to southern California in the intertidal zone. The largest individuals of Pisaster can reach diameters of up to across; they all develop five arms, but some may be lost from injury or disease, and occasionally the re-growth of an injured arm will result in an individual with more than five arms.