At the larval stage, Pisaster ochraceus are filter feeders, eating plankton.
Like all sea stars, an adult P. ochraceus has tube feet which they use for locomotion and for handling prey. Pisaster ochraceous feeds on mussels, chitons, and limpets, which they slowly pry open and devour. Snails, barnacles, echinoids, even decapod crustacea are also eaten. Pisaster ochraceous everts its stomach over the prey if it is too large to be swallowed whole, and digests the prey before swallowing it.
Animal Foods: mollusks; aquatic crustaceans; echinoderms; other marine invertebrates; zooplankton
Plant Foods: phytoplankton
Foraging Behavior: filter-feeding
Primary Diet: carnivore (Eats non-insect arthropods, Molluscivore , Eats other marine invertebrates); planktivore