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
• Habitat: Rocky Reef

• IUCN Threat Status: Not Evaluated
• Occurrence: Infrequent (9% 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 (99 per transect)
  Abundance is calculated as the average number of individuals recorded per RLS transect, where present.