A soft warty side-gilled slug out on open sand and rubble after dark.
A soft-bodied slug to about 8 cm, the back covered in low rounded warts of uneven size rather than the close polygonal paving of the larger Pleurobranchus, and coloured cream, yellow-brown or pink-brown with darker mottling between the warts. Two rolled rhinophores stand at the front with a broad oral veil below them, and the single feathery gill lies along the right side of the body between the mantle and the foot. That gill is the family character, and it is the reason a pleurobranch is not a nudibranch even though it is usually filed with them.
Colour and wart pattern vary enough that individual animals look quite different from one another, and the reliable separation from the larger species on the same ground is size and the surface of the back: P. forskalii and P. grandis reach two and three times the length and carry flat-topped tubercles set close together like paving.
Nocturnal, and found crossing open sand and rubble rather than on structure. It feeds on colonial ascidians. Members of the genus secrete mucus of very low pH, with sulphuric acid measured in some, and disturbed animals can flap the mantle margin and swim clear of the bottom for a short distance. Recorded from about 3 to 30 m.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.
