Sohal surgeonfish

Taxonomy

The sohal surgeonfish was first formally described in 1775 as Chaetodon sohal by the Swedish-speaking Finnish naturalist, explorer and orientalist Peter Forsskål with its type locality given as the Red Sea. Forsskål proposed Acanthuirus as a subgenus of Chaetodon although he recognised that it was probably different from Chaetodon even at the family level. In 1856 Desmarest designated Teuthis hepatus, which had been described from a type now known to have been collected at Ambon Island in the Moluccas (other erroneous type localities were named) in 1758 by Linnaeus, as the type species of the genus. In 2014 it was proposed that the type species of Acanthurus should be C. sohal, which had also been described by Forsskål in 1775 as a member of the subgenus alongside C. bifasciatus, C. nigrofuscus and C. unicornis, and had been designated as the type species by Jordan and Evermann in 1917. The genus Acanthurus is one of two genera in the tribe Acanthurini which is one of three tribes in the subfamily Acanthurinae which is one of two subfamilies in the family Acanthuridae.

Etymology

The sohal surgeonfish's specific name, sohal, is the Arabic name for this species along the Red Sea coast.

Description

The sohal surgeonfish has its dorsal fin supported by 9 spines and 30 or 31 soft rays while the anal fin is supported by 3 spines and 28 or 29, typically 29, soft rays. The depth of the body is around half the standard length. This fish has longitudinal, thin black stripes separated by greenish olive stripes and these join together at the spine on the caudal peduncle. The stripes are finer and more sinuous on the upper body but broader and straighter on the lower body. The stripes are greyer on the upper head and nape. The lower head and ventral surface of the body are pale with faint grey and greenish grey longitudinal lines the dorsal, anal and pelvic fins are black with vivid blue margins, there is a large patch of orange on the body underneath the pectoral fin and the sheath of the spine on the caudal peduncle is orange. The caudal fin is lunate. This species has a maximum published total length of 40 cm.

Distribution and habitat

The sohal surgeonfish is endemic to the northwestern Indian Ocean where it is found in the Red Sea, east along the coast of the Arabian Peninsula to the Persian Gulf. It is usually found on the outer edges of fringing reefs that are exposed to surge, typically down to depths of around 20 m.

Biology

The sohal surgeonfish may be encountered either singly or in small schools and is known to be very territorial. The spine on the caudal peduncle has been reported to bear venom. It grazes on algae growing on hard substrates and despite being solitary they will school to graze in the territories of other fishes. The territory guards food resources and the territory holder may shelter and otherwise spend a lot of time out of its territory or patrolling its boundaries.

Utilisation

The sohal surgeonfish is targeted by fisheries as a food fish and is also traded in the aquarium trade.

References

References

1. (2012). "''Acanthurus sohal''".
2. (2015). "''Acanthurus sohal'' (Persian Gulf assessment)". The IUCN Red List of Threatened Species.
3. {{FishBase. Acanthurus. sohal. (2023)
4. {{Cof genus
5. {{Cof family
6. [[Ronald Fricke]]. (2008). "Authorship, availability and validity of fish names described by Peter (Pehr) Simon Forsskål and Johann Christian Fabricius in the 'Descriptiones animalium' by Carsten Niebuhr in 1775 (Pisces)". Stuttgarter Beiträge zur Naturkunde A, Neue Serie..
7. Vahe D. Demirjian. (2014). "''Acanthurus'' Forsskål, 1775 (Osteichthyes, ACANTHURIDAE): proposed conservation by designation of ''Chaetodon sohal'' Forsskål, 1775 as the type species". Bulletin of Zoological Nomenclature.
8. (2016). "Fishes of the World". Wiley.
9. (12 January 2021). "Order ACANTHURIFORMES (part 2): Families EPHIPPIDAE, LEIOGNATHIDAE, SCATOPHAGIDAE, ANTIGONIIDAE, SIGANIDAE, CAPROIDAE, LUVARIDAE, ZANCLIDAE and ACANTHURIDAE". Christopher Scharpf and Kenneth J. Lazara.
10. [[John E. Randall]]. (2022). "Coastal Fishes of the Western Indian Ocean". South African Institute for Aquatic Biodiversity.
11. Michel Bariche1. (2019). "Records of two non-indigenous fish species ''Synanceia verrucosa'' Bloch and Schneider, 1801 and ''Acanthurus sohal'' (Forsskål, 1775) from the Gaza strip (eastern Mediterranean Sea)". BioInvasions Records.