Habitat: Common on protected sides of rocks, under rocks, and in caves and pools, more frequently where rock is encrusted with sponges and bryozoans, low intertidal zone, subtidal to over 400 m.
The sea star feeds on bacteria and other tiny particles, which are captured in mucus and swept to the mouth by ciliated tracts. It may also feed by applying the stomach to the surfaces of sponges and bryozoa.
Breeding habits in the sea star vary with size. Smaller females brood their eggs in a depression around the mouth formed by arching the arms. Larger females discharge eggs directly into the water and do not brood them. The sperm have spherical heads and the eggs are orange-yellow and yolky, and development is direct.
Photos: Stuart Wobbe