Also known as Bluelip Bristletooth, Doctorfish, Lancetfish, Reef Tang, Short-tail Bristletooth, Straited Surgeonfish, Thorntail, Thorntail Fish, Twospot Surgeonfish, Yelloweye Bristletooth.
Found singly or in small schools, around upper parts of reef slopes, over inner and outer reefs, rich in coral growth.
They feed on algae.
Juveniles yellow, gradually changing to orangey brown, but always keeping a yellow ring around eyes.
Length - 16cm
Depth - 1-45m
Widespread 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/Ctenochaetus-cyanocheilus