Atagema osseosa

Atagema osseosa is a species of sea slug or dorid nudibranch, a marine gastropod mollusk in the family Discodorididae.

Distribution
This species is found in the tropical Indo-West Pacific Ocean, with records at least from the coasts of India and eastern Australia.

Description
This nudibranch has evolved to mimic closely in appearance the sandy-coloured sponge on which it both lives and feeds off.

Ecology
Like many nudibranchs, this species feeds on sponges.