Solaster stimpsoni Verrill, 1880

Common name(s): Stimpson's sun star, Sun star, Orange sun star

Phylum Echinodermata
 Class Asteroidea
  Order Spinulosida
   Suborder Eugnathina
    Family Solasteridae
Solaster stimpsoni subtidal from Sares Head, WA.
(Photo by: Dave Cowles, 1997)
Description:  This large mostly subtidal seastar has 9-12 (usually 10) rays and no pedicellariae.  The paxillae on the aboral surface are crowded together giving a rather smooth grainy texture.  The disk is about 1/4 the total diameter.  Aboral surface usually red, pink, or orange with a gray or blue streak down the center of each ray from a patch from the central disk.  Up to 50 cm diameter

How to Distinguish from Similar Species: Other sun stars have a central disk about 1/3 the total diameter and no prominent dark streaks on the aboral surface.  The other most common sun star, S. dawsoni, has an orange, brown, tan, or mottled aboral surface.

Geographical Range: Bering Sea to Salt Point, Sonoma County, CA (not common in California); Japan

Depth Range: Extreme low intertidal to 610 m

Habitat: Mostly rocky subtidal; occasionally on floats and pilings.

Biology/Natural History:  Feeds on small sea cucumbers, including Eupentacta quinquesemita, E. pseudoquinquesemita, Cucumaria miniata, C. curata, and Psolus chitonoides.  May also eat tunicates such as Pyura haustor, brachiopods, and sea pens.  Another common sun star, Solaster dawsoni, is an important predator of this species.  May have a commensal polychaete scaleworm Arctonoe pulchra or Arctonie vittata in the ambulacral groove.  A parasitic barnacle Dendrogaster sp may be inside the tissues.  Eggs are 0.9 to 1 mm diameter, yellow.  Juveniles often hide among tubedwelling polychaete Phyllochaetopterus prolifica.

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Dichotomous Keys:
Flora and Fairbanks, 1966
Kozloff 1987, 1996
Smith and Carlton, 1975

General References:
Gotshall and Laurent, 1979
Kozloff, 1993
Morris et al., 1980
Niesen, 1994
O'Clair and O'Clair, 1998

Scientific Articles:

Hotchkiss, Frederick C., 2000. On the number of rays in starfish. American Zoologist 40:3 pp. 340-354

Knott, K. Emily, and Gregory A. Wray, 2000. Controversy and consensus in Asteroid systematics: new insights to Ordinal and Familial relationships. American Zoologist 40:3 pp. 382-392

McEdward, Larry R. and Benjamin G. Miner, 2006.  Estimation and interpretation of egg provisioning in marine invertebrates.  Integrative and Comparative Biology 46:3 pp 224-232

General Notes and Observations:  Locations, abundances, unusual behaviors:

This individual is more blue than usual and appears to be devouring Robbie Wheeling.  Note tape on lab in background--the major 2002 lab fire had just occurred.

Seasters breathe and rid themselves of wastes via coelomic pouches or papulae that they extrude through their skin when underwater.  The extruded papulae
give them a fuzzy appearance when underwater.  Photo of Solaster stimpsoni by Dave Cowles, Jule 2005.

Authors and Editors of Page:
Dave Cowles (2005):  Created original page