Description

Also known as Blue Unicornfish, Bluetail Unicornfish, Doctorfish, Lancetfish, Thorntail, Thorntail Fish.

Found in schools, patrolling mainly along outer reef walls, in pursuit of plankton.
They feed on plankton.
Length - 40cm
Depth - 15-45m
Western Central Pacific - Indonesia, Philippines

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.in/summary/Naso-caeruleacauda.html