Bluelined Surgeonfish

Acanthurus mata, commonly known as the pale surgeonfish, blue-lined surgeonfish, mata surgeonfish, striped surgeonfish, tailring surgeon, white-tail lancet, or yellowmask surgeonfish, is a marine ray-finned fish species belonging to the family Acanthuridae, which includes surgeonfishes, unicornfishes, and tangs. This species is prevalent throughout the Indo-Pacific region.

The species was first formally described in 1829 by the French zoologist Georges Cuvier under the name Chaetodon mata. The description did not specify a type locality, although the Corundefineddel Coast of 🇮🇳 India is recognized as its origin. The genus Acanthurus, to which this species belongs, is one of two genera within the tribe Acanthurini, itself one of three tribes in the subfamily Acanthurinae, which constitutes one of the two subfamilies in the family Acanthuridae.

The specific epithet "mata" is derived from the local name reported by Patrick Russell in 1803 for this fish on the Corundefineddel Coast.

Acanthurus mata is a medium-sized fish, capable of reaching a maximum length of 50 centimeters (approximately 20 inches). It features an oval-shaped and laterally compressed body. Similar to other surgeonfishes, Acanthurus mata propels itself using its pectoral fins. The caudal fin is crescent-shaped, and its small, pointed mouth is distinctive. The body is adorned with horizontal bluish lines against a brown background; however, the species can alter its coloration to a uniform grey-blue. A notable longitudinal yellow stripe passes across the eye, splitting into two lines extending anteriorly. Furthermore, the superior lip exhibits a yellow hue. Both dorsal and anal fins display a bluish tint with a yellow reflection, and the base of the anal fin is highlighted by a thin black line. Acanthurus mata is equipped with a sharp erectile spine at the base of the tail, functioning as a defensive mechanism.

The geographical distribution of Acanthurus mata is extensive across tropical waters, spanning from the western 🌊 Indian Ocean to archipelagos in the central 🌊 Pacific Ocean. It is encountered from the 🌊 Red Sea and 🌊 Gulf of Oman, extending south to Natal and eastward to the Society and Marquesan Islands, reaching as far north as southern 🇯🇵 Japan and south to New South Wales and 🇳🇨 New Caledonia (🇫🇷 Overseas France). Juveniles have been observed as far south as Sydney. Reports indicate its presence in Western Australia, specifically south to Shark Bay, but it is absent from the Hawaiian Islands, Pitcairn Islands, and Rapa. In 2021, sightings of the species were recorded off the Galápagos Islands in the Tropical Eastern Pacific.

Acanthurus mata typically inhabits steep slopes surrounding coral reefs at depths ranging from 5 to 45 meters. It is primarily a planktivorous species with a preference for zooplankton.

The species exhibits diurnal activity patterns, being solitary while resting on reefs but occasionally forming small aggregations in open water during feeding periods.