This mollusc has a light brown to bluish body and a single , plumed gill on the right side of the body. Opisthobranchs are characterized by two pairs of tentacles and a single gill behind and to the right of the heart (from which the group derives its name, Greek opisthen, behind + brankhia, gills). There is no marked distinction between head and mantle. The tentacles, situated close to the mouth, are used for orientation. Behind them you can find the rhinophores, olfactory organs often with complex formsThe rhinophores are rather large and are orange in colour. The middle part of the foot is the sole, used for locomotion.
This species is known to feed on sponges including large orange barrel sponges where it has been observed boring large holes.Maximum length is about 16cm.
Opisthobranchia are known from the Carboniferous to the recent periods
Possibly the major threat to this and similar species would be habitat loss and declining water quality.