Rostanga bifurcata is a species of sea slug, a dorid nudibranch, a marine gastropod mollusc in the family Discodorididae.
This species was described from Botany Bay, Sydney, Australia. It has subsequently been reported from western Australia, Singapore, Hong Kong, and Tasmania.[1]
This dorid nudibranch is red, and the dorsum is covered with caryophyllidia; it is very similar to other species of Rostanga.
This nudibranch is found on a colony of the red sponge, Antho chartacea (family Microcionidae) on which it presumably feeds. Most other species of Rostanga also feed on sponges of the family Microcionidae.