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:Red Sea
Only occurs in the Red Sea, Arabian Sea and Arabian Gulf. Along outer edge of reef flats to about 10 m depth. Juveniles and often adults are solitary and territorial, but occur also in small groups. Easily identified by the numerous black lines on the body in all stages. Peduncular spine is thought to be venomous. Length to 40cm.