About Acanthurus dussumieri Valenciennes, 1835
Acanthurus dussumieri is a deep-bodied, laterally compressed oval fish that reaches a maximum length of 54 cm (21 in). It has a small head with slightly prominent eyes, a small beak-like mouth, and inflated, pale lips. Its body is covered in small scales that give it a smooth texture. Like other surgeonfish, it has a pair of scalpel-shaped modified scales on its caudal peduncle; these structures can be folded flat against the body or raised for defense. Both its dorsal and anal fins are long, and it uses its pectoral fins for locomotion and balance. Its throat is blue, and the rest of its head is marked by a dense network of blue or grey-blue lines. These head lines are wider than the fine, wavy, longitudinal grey-blue lines that pattern its pale brownish body. It has a broad orange bar above its eyes, and a narrow orange band borders the base of its dorsal fin. Its scalpel-like modified scales are white, and each is surrounded by a black blotch. Its caudal fin is crescent-shaped: it is dark blue speckled with black, except for its pale base. Alongside Acanthurus mata and Acanthurus xanthopterus, this species is one of the largest surgeonfish in the world. Young juvenile fish are initially greyish with yellow and black caudal fins; their body color darkens to brown as they mature, then lightens again as they continue to grow, and the species’ characteristic longitudinal wavy body lines and facial patterning develop gradually. This surgeonfish has a wide distribution across tropical and subtropical waters of the Indian Ocean and western Pacific Ocean. Its range extends from East Africa to southern Japan, Indonesia, and eastern Australia, and it occurs at depths down to approximately 130 m (427 ft). It can be found in lagoons, on reefs, on reef slopes, and in inter-reef areas with sand, rubble, or rock substrates. Juveniles and young adults are most often associated with reef habitats. Acanthurus dussumieri feeds on algae and detritus. Its diet includes the algal film that grows on rocks and other hard surfaces, as well as diatoms and planktonic particles. Very little research has been conducted on the reproduction of this species. Adult individuals are either solitary or gather in small groups, while juveniles form shoals.
