News / Species Spotlight / Sohal Tang (Acanthurus sohal) (03/21/18)

Sohal Tang (Acanthurus sohal)

Species Spotlight - Sohal Tang (Acanthurus sohal)
In the late 18th century, a young Swedish naturalist named Peter Forsskl journeyed to Egypt and Yemen in an effort to study the regions little-known plantlife. Along the way, he encountered many new species of fish at the local markets which he dutifully preserved and studied. Many of these were eventually named by him, though this was done posthumously, as he ultimately died of Malaria before he could complete this expedition.

Today, many familiar aquarium fishes find their origins with the work of Peter Forsskl, and, interestingly, many of the names used stem from the local Arabic nomenclature. The Siganus rabbitfishes come from an Arabic word for jailer and the Abudefduf damselfishes translates loosely as the fish with mixed sides, in reference to its prominent stripes.

The Sohal Tang (Acanthurus sohal) is a particularly interesting example, as both the genus and species were described by Forsskl, and these stem from both Greek and Arabic roots. Acanthurus derives from the Greek for spined tail, in reference to the caudal spine found in all members of the surgeonfish family. The species epithet is Arabic and represents the only example of it having been used for a fish (or apparently for any other scientific name). Its meaning is to file or pare and most likely references the same caudal fin spine.

The Sohal Tang occurs only in the waters of the Red Sea and east into the Persian Gulf. There are also some found at Socotra, along the easternmost tip of Africa, but here they frequently hybridize with the closely related Clown Tang (A. lineatus). These two species form a distinctive group among the Acanthurus surgeonfishes, possessing a notably elongated body, large size, venomous spine, and, less obviously, a low number of gill rakers.

The venomous spine is noteworthy. The bright orange color that surrounds it is clearly an aposematic warning to any potential predators or algivorous competitors to stay away. Unlike most Acanthurus, the Sohal and Clown Tangs maintain territories on the reef which they defend vigorously. Even divers are not safe from their wrath.

The diet is mainly comprised of short filamentous red and green algae. This should be replicated as best as possible in captivity by offering a mix of foods rich in vegetable matter. Specimens will also greedily accept meaty foods, but a menu rich in these is highly unnatural and is likely to lead to longterm health problems. Lastly, the Sohal Tang is notoriously aggressive towards tankmates, especially when at a mature size, so great care must be taken. Only the largest of aquariums are suitable for adult specimens, and closely related surgeonfishes are likely to bullied relentlessly. But, for those with the appropriate accommodations, Acanthurus sohal is a uniquely beautiful centerpiece to any fish collection.