is such a striking flatworm that it cannot be confused with any other. It may be mistakenly be identified as a sea slug due to the anterior tentacles and bright colouration. However, Prostheceraeus vittatus
has none of the dorsal processes of the sea slugs, it is extremely thin (dorso-ventrally flattened) and the tentacles are formed by folds of tissue at the margin of the body. These features distinguish it from sea slugs. Prostheceraeus vittatus
has a yellow-white or cream body with numerous dark longitudinal stripes. It crawls along the seabed using cilia and may swim by sinuous movements of the body.