About Acanthurus mata (Cuvier, 1829)
Acanthurus mata (Cuvier, 1829) is a medium-sized surgeonfish that reaches a maximum length of 50 centimetres (20 inches). Its body is oval-shaped and laterally compressed, and like other surgeonfishes, it swims using its pectoral fins. The caudal fin is crescent-shaped, and the mouth is small and pointed. Its base body color is brown, patterned with horizontal bluish streaks, and the species can change color over time to become solid grey-blue overall. A long yellow stripe runs across the eye, splitting into two lines that extend forward in front of the eye; the upper lip is also yellow. The dorsal and anal fins are bluish with a yellow sheen, and the base of the anal fin is marked by a thin black line along its lower edge. Like other surgeonfishes, it has a sharp, erectile scalpel-like spine at the base of the tail, which it uses as a defensive weapon, giving the group its common name.
Acanthurus mata has a broad distribution across tropical Indo-Pacific waters, ranging from the western Indian Ocean to the central Pacific archipelagos. Its range extends from the Red Sea and Gulf of Oman south to Natal, east to the Society and Marquesan Islands, north to southern Japan, and south to New South Wales and New Caledonia. Juveniles have been recorded as far south as Sydney (R. Myers pers. comm. 2010). The species is also found in Western Australia, ranging south to Shark Bay (Allen and Swainston 1988). It is not confirmed to occur in the Hawaiian Islands, Pitcairn Islands, or Rapa (Randall 2001a). In 2021, the species was newly recorded off the Galápagos Islands in the Tropical Eastern Pacific.
This species typically inhabits steep slopes around coral reefs, at depths between 5 and 45 meters.
