Chromodoris sphoni
This is a true nudibranch, of the order Nudibranchia. The name means "naked gills." Where branchia refers to gills.
The suborder Doridacea contains the greatest number of species of nudibranchs in the world.
The Chromodorid family is large, with an estimated 300+ species throughout the world.
Chromodorids often feed on sponges. They are usually very finicky eaters, and will only except one species of porifera. Sponges produce toxic chemicals which are absorbed by the nudibranchs and concentrated in mantle glands on their backs. These presumably make the nudibranchs a low point on a potential predators menu.
