Sohal Surgeonfish

Acanthurus sohal (Forsskål, 1775)

syn. Acanthurus carinatus, Aspisurus sohar, Chaetodon sohal, Chaetodon sohar, Choetodon sohab, Ctenodon ruppelii

40 cm1-20 mDangerousVenomousLeast Concern

2721

The sohal surgeonfish, scientifically known as Acanthurus sohal, is a marine ray-finned fish found predominantly in the northundefined, particularly around the 🌊 Red Sea and the 🌊 Persian Gulf, extending to the Mediterranean Sea. Reaching up to 40 centimeters (16 inches) in length, this fish prefers the outer edges of coral reefs, typically at depths ranging from 1 to 20 meters (3 to 66 feet). First described in 1775 by Peter Forsskål, the sohal surgeonfish takes its specific name from the Arabic term "sohal," a nod to its regional distribution along the 🌊 Red Sea coast.

Characterized by its striking appearance, the sohal surgeonfish displays a unique pattern of thin black stripes alternating with greenish olive stripes that meet at a distinctive spine on its caudal peduncle. The dorsal fin comprises 9 spines and 30 or 31 soft rays, while the anal fin has 3 spines and usually 29 soft rays. The caudal fin forms a crescent shape, also known as lunate. Additionally, the fish features black dorsal, anal, and pelvic fins with vivid blue margins, an orange patch beneath the pectoral fin, and an orange sheath on the caudal peduncle spine, which is noted to carry venom.

Living a largely solitary existence, the sohal surgeonfish is territorial, fiercely guarding its food resources within its chosen stretch of reef. Although it primarily feeds on various types of algae such as Sargassum and fine filamentous green algae, it occasionally forms small schools to forage within other fish territories. The species is known to be aggressive, often encountered alone or in small groups, and spends considerable time patrolling its domain.

In addition to its ecological role on the reefs, the sohal surgeonfish holds value in local fisheries as a food source and is popular in the aquarium trade, although it is typically caught with nets, traps, or occasionally trawls. Encounters in the Mediterranean Sea in recent years are attributed to either release from aquariums or migration through the Suez Canal (🇪🇬 Egypt).

Why it's threatened

Biological resource use

Intentional use: (subsistence/small scale) [harvest]

There have been localized population declines recorded from Saudi Arabia.

Surgeonfishes show varying degrees of habitat preference and utilization of coral reef habitats, with some species spending the majority of their life stages on coral reef while others primarily utilize seagrass beds, mangroves, algal beds, and /or rocky reefs. The majority of surgeonfishes are exclusively found on coral reef habitat, and of these, approximately 80% are experiencing a greater than 30% loss of coral reef area and degradation of coral reef habitat quality across their distributions. However, more research is needed to understand the long-term effects of coral reef habitat loss and degradation on these species' populations. Widespread coral reef loss and declining habitat conditions are particularly worrying for species that recruit into areas with live coral cover, especially as studies have shown that protection of pristine habitats facilitate the persistence of adult populations in species that have spatially separated adult and juvenile habitats (Comeros-Raynal et al. 2012).

Threat classification from the IUCN Red List.