Archaster angulatus

Angular seastar
Archaster angulatus
Archaster angulatus, Photo: Graham Edgar


Temperate Australasia, Tropical Indo-Pacific


Dull grey colour underwater, but oranges or reds are revealed when exposed to sunlight. It is the only seastar known to entwine in pairs or larger groups when spawning. It is a moderately common seastar found half-buried in sand off the southwestern Australian coast.


Max Size: 16 cm

Sea Temperature Range: 15.9-22.4°C

Depth: 0-50m

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: Widespread (100% 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: Solitary (1 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