AT A GLANCE
- Common Name: Sohal Surgeonfish
- Scientific Name: Acanthurus sohal
- Category: Fish
- Subcategory: Bony Fishes
- Range: Red Sea and the northwestern Indian Ocean, including the Gulf of Aden and the Persian Gulf
- Habitat Type: Shallow, wave-swept seaward coral reef crests, surge channels, and outer reef slopes from 0.5 to 10 meters depth
- IUCN Red List Status: Least Concern
- Lifespan: 15 to 25 years (up to 30 years in protected marine reserves)
- Diet: Herbivorous/Algivorous (specialized grazing on filamentous green and red turf algae, with occasional consumption of soft coral polyps)
- Average Size/Weight: Total length 35 to 40 cm; weight 1.2 to 2 kg
- Key Defining Feature: Large, aggressive surgeonfish adorned with intricate horizontal zebra stripes of pale blue and charcoal, electric-blue fin margins, and a venomous, razor-sharp orange caudal spine
Overview
The Sohal Surgeonfish (Acanthurus sohal), also known as the Majestic Surgeonfish or Red Sea Clown Surgeonfish, is one of the most strikingly patterned, aggressive, and iconic reef fishes of the Red Sea. Belonging to the surgeonfish family Acanthuridae, this muscular grazer rules the turbulent surge crests of Arabian coral reefs. Celebrated for its mesmerizing, zebra-like horizontal pinstripes and glowing electric-blue fin trims, it is equally famous for its fearless territorial temperament, fiercely defending its algal gardens from all intruders.
Biology and Physical Characteristics
Acanthurus sohal has a deep, oval-shaped, highly compressed body covered in tiny ctenoid scales. Its body is adorned with an intricate, hypnotic tapestry of fine, wavy horizontal stripes of pale silvery-blue and dark charcoal-grey that run from behind the gill cover to the tail. The dorsal, anal, and pelvic fins are deep soot-black, edged in an immaculate, glowing margin of brilliant neon-electric blue. The caudal fin is deeply lunate with extended points. Mounted on each side of the caudal peduncle is a formidable, forward-curving, razor-sharp modified scale (scalpel) wrapped inside a protective sheath and highlighted by a vivid, warning spot of fiery orange-red.
Behavior and Ecology
Sohal Surgeonfish are among the most territorial herbivores on the coral reef. Each adult establishes a personal grazing territory covering several square meters of high-energy reef crest, where sunlight promotes rich carpets of filamentous algae. The Sohal guards this private pasture with unrelenting aggression, charging and tail-swiping at parrotfish, rabbitfish, and other surgeonfish. When attacking, it swims alongside the competitor and rapidly flexes its caudal peduncle, using its sharp orange scalpel to inflict deep, painful defensive slashes.
Conservation and Human Impact
The Sohal Surgeonfish is classified as Least Concern on the IUCN Red List. It is abundant throughout its native range in the Red Sea and Persian Gulf, where vast protected fringing reefs support thriving populations. It is highly valued in the international marine aquarium trade, requiring regulated export monitoring from Red Sea nations.
Interesting Factoid
The Sohal Surgeonfish is so fiercely territorial that it will boldly attack and tail-whip human scuba divers who accidentally swim too close to its favorite patch of seaweed.