Convict surgeonfish
(Acanthurus triostegus)
General data
The convict tang is so called because of its bold black stripes on a yellowish background.
It is a laterally-compressed oval-shaped fish with a maximum length of about 26–27 cm (10–11 in).
The head is small with a pointed snout and a terminal mouth with thick lips. It has six black stripes which distinguishes it from the zebra tang (Acanthurus polyzona) which has nine, and has a more restricted range in the Indian Ocean. The first black stripe is oblique and passes through the eye. There are two black spots on the caudal peduncle, and on each side there is a sharp, retractable spine, which is used in offence or defence.
Acanthurus triostegus occurs in the tropical Indo-Pacific region. Its range extends from the East African coast and Madagascar to southwestern Japan, Australia and Central America, including many Pacific island groups. It is found over hard bottoms in lagoons, reef slopes, bays and estuaries. Juveniles are common in tide pools, and larger fish are found at depths down to about 90 m (300 ft).
