Biology/Natural History: Prey include diatoms, sponges, bryozoans, sea pens, anemones, sea cucumbers, sea urchins, and chitons, ascidians, and fish eggs. Anemones are said to be one of its major prey items. It usually swallows its prey whole and digests them internally. The swimming anemone Stomphia sp has a strong escape response from this species; as does the purple urchin Strongylocentrotus purpuratus. Stomphia swims away, while S. purpuratus pulls in its tube feet, depresses its spines, and extends its pedicellariae; then races away. The scaleworm Arctonoe vittata is a common commensal, and the worm and the seastar are mutually attracted to one another. A parasitic barnacle Dendrogaster sp may be found inside. In Wasington, spawning is from April to August. Females release yellow eggs which are fertilized in the water.