Also known as Achilles Surgeonfish, Doctorfish, Lancetfish, Orange-spot Surgeonfish, Redspot Surgeonfish, Redtail Surgeonfish, Red-tailed Surgeon, Thorntail, Thorntail Fish.
Found singly or in schools over sand bottoms of shallow, clearwater seaward reefs.
They feed on algae.
Length - 24cm
Depth - 0-10m
Widespread Eastern Central Pacific, Western Pacific
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. Ref: https://www.fishbase.se/summary/4306