Patiriella regularis

Regular seastar
Patiriella regularis
Patiriella regularis, Hobart, TAS, Photo: Graham Edgar
Patiriella regularis
Patiriella regularis, Hobart, TAS, Photo: Graham Edgar
1 / 2
Patiriella regularis
Patiriella regularis


Temperate Australasia


Olive green species with some similarity to the smaller intertidal species Parvulastra exigua, although that species has a more brownish colouration. Within Australia, P. regularis has only been found in southeastern Tasmania, but it is a dominant species on intertidal rocks in that area and appears to outcompete other grazing seastars. It feeds on the film of algae and microbes coating rock surfaces. Like a number of other species (e.g. the screw shell Maoricolpus roseus, the chiton Chiton glaucus and the crab Cancer novaezelandiae), this species is believed to have been accidentally introduced into the country when transported to Tasmania with oysters early last century.


Max Size: 7 cm

Sea Temperature Range: 10.3-21.9°C

Depth: N/A

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: Infrequent (8.5% 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: Many (98 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