Coscinasterias muricata
Eleven-arm star
Coscinasterias muricata, Hobart, TAS, Photo: Graham Edgar
Coscinasterias muricata, Adelaide, SA, Photo: Ian Shaw
Coscinasterias muricata, Bass Strait, TAS, Photo: Graham Edgar
Coscinasterias muricata, Port Stephens, NSW, Photo: Andrew Green
Similar Species
Same Genus
Distribution
Temperate Australasia
Description
Mottled appearance, with rows of large spines surrounded by discs along its upper surface. The number of arms is usually 11, but can vary from 7 to 14. While the species can also act as a scavenger, Coscinasterias muricata is such an active predator of molluscs in sheltered marine habitats that it is considered a keystone species; it can alter community structure by preventing the establishment of beds of mussels, scallops, etc. The species was called C. calamaria until recently. That name is now reserved for a close tropical relative, which has slightly differently shaped plates on the arms. If broken off, each arm can regenerate into a complete animal.
Information
Max Size: 50 cm
Sea Temperature Range: 10.3-23.6°C
Depth: 0-150m
Habitat Generalization Index: N/A
Also referred to as the SGI (Species Generalisation Index), this describes the habitat niche breadth of the species. Species with values less than 15 are found in a relatively narrow range of reef habitat types (specialists), while those over 25 may be found on most hard substrates within their range (generalists). Learn more here.
Conservation and Rarity
IUCN Status: Not Evaluated
Occurrence: Common (21.3% of sites)
Occurrence describes how often the species is found on surveys within its distribution. It is calculated as the % of reef sites surveyed by RLS divers across all the ecoregions in which the species has been observed
Abundance: Few (4 per transect)
Abundance is calculated as the average number of individuals recorded per RLS transect, where present.
Edit by: GJ Edgar. 2008. Australian Marine Life. New Holland, Sydney