Coral Nudibranch, Phyllodesmium horridum

The Coral Nudibranch, (Phyllodesmium horridum), is a species of sea slug in the Facelinidae family. It is found off Australia and Japan, as well as around the South African coast from False Bay to Sodwana Bay. This species is intertidal, existing in the low to high tide regions, but some reaching depths up to 100 feet below sea level.

This creature is a marine gastropod mollusc. It generally reaches a length of up to 1 inch. However, specimens around the South African coast have been known to grow up to 1.6 inches long. It is a slender pale-bodied gastropod with long paired pinkish cerata (lateral outgrowths). The cerata have a bluish-white stripe running down their length, as does the body. Its rhinophores (hornlike tentacles) are smooth.

This slug feeds on corals of the genus Melitodes. It also feeds on gorgonians of the genus Acabaria. Its egg ribbon is a gelatinous mass with many small white eggs.