How to Distinguish from Similar Species: Pteraster tesselatus, Dermasterias imbricata, and Asterina miniata have similar shapes but do not have the large marginal plates. The aboral surface of Asterina miniata has ossicles but they are crescent-shaped. Pteraster tesselatus and Dermasterias imbricata have a smooth aboral surface.
Geographical Range: Chignik Bay, Alaska to Baja California
Depth Range: Low intertidal to 503 meters. In our area almost exclusively subtidal (deeper than 15 m). May be seen in fairly shallow, protected waters.
Habitat: Varies. Especially on rocky areas.
Biology/Natural History: An omnivorous predator. Prey include sponges, bryozoans, sea pens,tunicates such as Aplidium californicum and Corella spp., algae, and detritus. Predators include the seastar Solaster dawsoni. Moves fairly fast for a seastar, up to 40 cm/minute. May have an internal parasitic barnacle Dendrogaster sp. In British Columbia spawns from March to May. Juveniles often congregate subtidally among tubes of the tubedwelling polychaete Phyllochaetopterus prolifica.
Flora and Fairbanks, 1966
Kozloff 1987, 1996
Smith and Carlton, 1975
Larry R. and Benjamin G. Miner, 2006. Estimation
of egg provisioning in marine invertebrates. Integrative and
Biology 46:3 pp 224-232
General Notes and Observations: Locations, abundances, unusual behaviors:
Closeup of the aboral surface of Mediaster aequalis. Note the round clusters of ossicles and the madreporite. Photo by Dave Cowles, July 2000
Authors and Editors of Page:
Dave Cowles (2005): Created original page