Generally has eight arms, but can vary from six to nine. Can reproduce asexually by splitting and each part growing new arms. Arms can be of varying lengths on an individual because of different stages of re-growth. On the aboral surface the arms have small spinelets in rows along the length.
Temperate inshore, continental shelf and slope areas of southern Australia, from South Solitary Island NSW to Houtman Abrolhos, WA; southwest Pacific (New Zealand). Depth range 0-238 m.
Australian Museum registration database records for the Sydney region:
Long Reef; Newport; Manly (Fairy Bower; Freshwater); Port Jackson (Balmoral Beach; Bottle and Glass Rocks; Shark Island); Botany Bay (Kurnell Reef); Coogee. Depth range 0-90 m.
Commonly found under rocks.
Taxonomic information - synonyms and type material:
Asteracanthion polyplax Müller & Troschel, 1844:178.
Type data: holotype ZMB.
Type locality: Tasmania (as Vandiemensland).