Biology/Natural History: Solaster dawsoni is a predator on other seastars, including Solaster stimpsoni, other Solaster dawsoni, Leptasterias hexactis, Evasterias troschelii, Dermasterias imbricata, Henricia leviuscula, Crossaster papposus,Pycnopodia helianthoides, and Mediaster aequalis. It also has been seen to feed on the sea cucumbers Eupentacta quinquesemita, Psolus chitonoides, Cucumaria miniata, and young Parastichopus californicus, and on the nudibranch Tritonia festiva, which swims away rapidly when touched. Many other seastars also move away quickly when touched by S. dawsoni. S. dawsoni moves along with its leading rays raised, and lunges forward (at least fast for a seastar) when it touches another star. S. stimpsoni, one of its favorite prey species, curls all its arms upward above the disk when encountered and sometimes wards off the attack. In Auke Bay, Alaska, S. dawsoni seems to eat mainly green urchins Strongylocentrotus droebachiensis. The commensal polychaete scaleworms Arctonoe vittata and Arctonoe fragilis are common on the star. Spawning occurs in mid April in southern British Columbia. Eggs are about 1 mm in diameter. Juveniles often take refuge among the tubedwelling polychaete Phyllochaetopterus prolifica.