Orange-socket Surgeonfish

Found in small schools, often mixing with other similar species, over shallow, protected reef flats and slopes, of lagoons and outer reef walls. They look almost black with only a white band around the tail and orange around the spine. (this is not always visible)
Juveniles found between soft corals, in very shallow lagoons.

Surgeonfish have a blade like spine in the tail that points outwards when bent, unicorns have two hook-like plates along the tail, these are used for defence and are as sharp as a surgeons scalpel, hence the name "Surgeonfish".
Some species are venomous.