[2] The aboral or upper surface is ivory white and covered with blunt tubercles in radially arranged rows.

The oral or under surface has the mouth in the centre and several rows of tube feet running down each ray on either side of the brownish ambulacral groove.

This is because the island groups in which it lives are very isolated and the brooded young will not be dissipated in an inhospitable ocean but will end up in a location already inhabited by starfish and therefore suitable for their development into adults.

Larger starfish also feed on amphipods, polychaete worms and the limpet Nacella delesserti, which makes up 90% of its diet by mass.

[2] In the Prince Edward Islands, Anasterias rupicola is the dominant invertebrate predator but it is itself sometimes eaten by seabirds such as the lesser sheathbill (Chionis minor) and the kelp gull (Larus dominicanus).

[4] Groups of up to fourteen starfish have been observed feeding on a single large limpet, each with part of their everted stomach inserted under its rim.