Small, long-armed seastar commonly found under rocks. The number of arms is generally eight, but ranges from six to nine, and several of these arms are usually noticeably smaller than others. This species reproduces by dividing asexually as well as by normal sexual means; each half of the original animal grows new arms to replace those lost. Occasionally an animal is found with a single large arm and seven small, recently formed stumps. A related species with five regular arms (Allostichaster regularis) is found from South Australia to southern Queensland.

• Max Size: 9 cm
• Sea Temperature Range: 10.6-25.5°C
• Depth: 0-238m

• IUCN Threat Status: Not Evaluated
• Occurrence: Infrequent (2% 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: Several (6 per transect)
  Abundance is calculated as the average number of individuals recorded per RLS transect, where present.