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. Various reef habitats, sand slopes and lagoons, and juveniles often in estuaries. Adults usually in aggregations feeding on sand and rubble surfaces. Capable of enormous colour changes, hence very similar to A.dussumieri and A.blochii, but always distinct by yellow pectoral fins. Juveniles with white lines on dorsal and anal fin. Length to 50cm