E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Dermasterias imbricata (Grube, 1857)
Leather Star
Family: Asteropseidae

© Kathryn Clouston  Email the photographer   (Photo ID #78052)

E-Fauna BC Static Map
Distribution of Dermasterias imbricata in British Columbia
Details about map content are available here.

Introduction


Family Description

Large disc (usually); short, broad arms. The aboral skeletal plates are sometimes meshlike, in regular radial rows, but usually covered with thick skin, which can be smooth, granulated or spiny. The marginal plates can vary from prominent to poorly developed, usually oblique or overlapping, sometimes with a small group of spinules on the outer edge or with a single spine; the edge of the disc is thin. The oral intermediates are parallel to the adambulacrals. The adambulacral plates have two series of spines sheathed in thick skin. The papulae can be single or grouped in dorsal radial areas. Bivalved or granuliform pedicellariae are sometimes present.

Species Information


Click on the image below to view an expanded illustration for this taxon. If more than one illustration is available for a species (e.g., two subspecies may be illustrated) then links to the separate images will be provided below.



Dermasterias imbricata has a characteristic smooth, slimy feel and smells like garlic. It is mottled reddish-brown and orange with a greenish-grey perimeter and rusty brown gill areas. The madreporite stands out as a large yellow dot. The five arms are up to 15 cm long and the arm-to-disc ratio is from 2.4 to 2.9. Few if any calcareous plates show through the leathery skin. Along each arm are six to eight rows of squarish areas containing up to 22 papulae and 1 to 9 pedicellariae in each. The smooth shape of the marginals shows through the leathery skin especially in a dried specimen. Each adambulacral has a single blunt furrow spine tipped with a fleshy knob and on the oral surface, a ridge of tough skin parallel to the furrow and a flat oval spinelet. D. imbricata has four rows of tube feet.

Similar Species

Dermasterias imbricata might be confused with Asterina miniata in general shape, but A. miniata is stiffer and feels like sandpaper.

Biology


The diet of Dermasterias imbricata varies with locality. On the exposed coast, it eats primarily sea anemones and some compound sea squirts, and in sheltered waters, mostly sea cucumbers as well as encrusting sponges and sea pens. Even though the sea cucumber Psolus chitonoides contains toxic saponins, 39 per cent of D. imbricata surveyed were feeding on it. All those observed in Gabriola Passage were feeding on bottom detritus. This sea star evokes a swimming-escape response in the sea anemones Stomphia didemon and S. coccinea, and presumably would eat them if it was able to catch them. Stomphia species detect imbricatine, an alkaloid chemical produced by D. imbricata. Seven other species of sea stars cause Stomphia species to release but do not eat them. D. imbricata also stimulates juveniles of the anemone Urticina piscivora to release their attachment; large U. piscivora may defend themselves by attacking the sea star, though they later regurgitate it. In California, D. imbricata usually feeds on the anemone Corynactis californica. In an aquarium, it prefers the sea anemones Anthopleura or Metridium; but in the ocean, these anemones are not regular prey items because in the intertidal zone they live too high and in the subtidal zone they grow too large for the sea star.

D. imbricata breeds from April to August. It sheds gametes via three paired gonopores in each arm radius. The yellow-to-orange eggs are 200 micrometres in diameter. In the Vancouver Island region, juveniles successfully settled and survived just once in five years. The scale worm Arctonoe vittata is found on D. imbricata; a study at Bodega Bay discovered that the sea star was attracted to the scale worm more than to food items, suggesting that the relationship may be of mutual benefit. The parasitic barnacle Dendrogaster can infect D. imbricata's reproductive organs.

Distribution

Distribution

Cook Inlet, Alaska, to La Jolla, California, from the intertidal zone to 91 metres depth on rocky substrates. Common in this region (the area from Glacier Bay to Puget Sound to a depth to 200 metres).

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)
COSEWIC
UnlistedUnlistedUnlistedUnlisted
BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Synonyms and Alternate Names

Asteropsis imbricata Grube

Additional Range and Status Information Links

Additional Photo Sources

General References


Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2019. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 19/11/2019 12:20:24 PM]
Disclaimer: The information contained in an E-Fauna BC atlas pages is derived from expert sources as cited (with permission) in each section. This information is scientifically based.  E-Fauna BC also acts as a portal to other sites via deep links.  As always, users should refer to the original sources for complete information.  E-Fauna BC is not responsible for the accuracy or completeness of the original information.


© E-Fauna BC: An initiative of the Spatial Data Lab, Department of Geography, UBC