Thorunna australis is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusk in the family Chromodorididae.[1]
This species was described from New Caledonia. It has been reported from Japan, the Philippines, Indonesia, the Marshall Islands and South Africa.[2]
This species is similar in shape and coloration to species of the Hypselodoris maculosa species complex, especially Hypselodoris paradisa.