The common name "surgeonfish" is derived from a characteristic that clearly distinguishes Acanthuridae from other fish families: the spines or "scalpels" on the caudal peduncle, one or more on each side. Based primarily on differences in this characteristic, the family can be divided into three subfamilies: The Acanthurinae, in which the peduncular spine rests in a groove and can be erected in defence during the fights, the Nasinae and Prionurinae in which the peduncular feature is arranged as one or more fixed blades on each side, that are sharp and elongate with age.
Place of origin:Western Indian Ocean
Widespread Indo-West Pacific. Shallow coastal to outer reef flats, often in exposed reefs subject to surge. Adults usually form schools and are commonly found in shallow reef-gutters. Juveniles solitary and secretive on shallow rubble habitats. Readily identified by the orange and blue lined pattern. Peduncular spine is venomous. Length to 35cm. Also known as Blue-lined Surgeonfish.