Also known as Doctorfishes, Lancetfishes, Thorntails, Thorntail Fish, Striped Surgeon, Lined Surgeon, Lined Surgeonfish, Blue Lined Surgeonfish, Blue Banded Surgeonfish, Bluebanded Surgeon, Clown Surgeon, Clown Surgeonfish, Pyjama Clown, Clown Tang and Tang Clown.
Found singly or in small groups on shallow reef flats, slopes and gutters usually exposed to surge currents.
Males are often found with a harem of females.
Small juveniles secretive among rubble boulders.
They feed on plankton and algae.
Length - 35cm
Depth - 1-10m
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: http://www.fishbase.org/summary/Acanthurus-lineatus.html