Sohal Surgeonfish

The sohal surgeonfish (Acanthurus sohal), also known as the sohal tang, is a marine ray-finned fish belonging to the family Acanthuridae, which includes the surgeonfishes, unicornfishes, and tangs. This species is primarily found in the northwestern 🌊 Indian Ocean.

Taxonomically, the sohal surgeonfish was first formally described in 1775 by Peter Forsskål as Chaetodon sohal. Forsskål proposed Acanthuirus as a subgenus of Chaetodon, but acknowledged that it was likely different from Chaetodon even at the family level. There have been discussions regarding the stability of the genera Acanthurus and Paracanthurus, with proposals to petition the International Commission on Zoological Nomenclature. In 2014, it was proposed that the type species of Acanthurus should be C. sohal. The genus Acanthurus belongs to the tribe Acanthurini, which is one of three tribes in the subfamily Acanthurinae within the family Acanthuridae.

The specific name "sohal" is the Arabic name for this species along the 🌊 Red Sea coast.

The sohal surgeonfish has a distinctive appearance with thin black stripes separated by greenish olive stripes. These stripes converge at the caudal peduncle spine. The upper body has finer and more sinuous stripes, while the lower body has broader and straighter stripes. The upper head and nape have a grayer tone compared to the lower head and ventral surface, which display pale colors with faint gray and greenish gray longitudinal lines. The dorsal, anal, and pelvic fins are black with vivid blue margins. There is also a large orange patch on the body beneath the pectoral fin, and the sheath of the caudal peduncle spine is orange. The caudal fin has a lunate shape. Maximum reported total length for this species is 40 cm (16 inches).

The sohal surgeonfish is endemic to the northwestern 🌊 Indian Ocean, specifically the 🌊 Red Sea and the coast of the Arabian Peninsula up to the Persian Gulf. In recent years, it has been observed in the Mediterranean Sea, most likely due to aquarium releases or Lessepsian migration through the Suez Canal (🇪🇬 Egypt). It typically inhabits the outer edges of fringing reefs exposed to surge, at depths of around 20 m (66 ft).

In terms of behavior, the sohal surgeonfish can be solitary or found in small schools. It is known to be highly territorial and the spine on its caudal peduncle has venom. This species primarily grazes on algae growing on hard substrates. Despite their solitary nature, they will school together to graze in the territories of other fishes. Territorial behavior is mainly driven by the defense of food resources, and the territory holder may spend a significant amount of time patrolling its boundaries or seeking shelter within its territory.