 "Archaster" has spines that are flat and blunt and on its upper surface has parallel, radial rows of plates while "Astropecten polyacanthus" does not.The comb star is found in shallow tropical and sub-tropical seas throughout the Indo-Pacific region from the Red Sea and Zanzibar to Hawaii, and from Japan to Australia and New Zealand.In Australia the range extends from Cape Naturaliste in the west, round the north coast to Sydney in the east.