Reef fish, saltwater
Powder Blue Tang
Acanthurus leucosternon
Oval-shaped, compressed body with a vibrant powder blue coloration, a bright yellow dorsal fin, a contrasting white face with a black mask, and white margins on the anal and pelvic fins. It has a retractable scalpel-like spine on each side of the caudal peduncle for defense.
- Habitat
- Inhabits shallow, clear coastal coral reefs and surge zo…
- Size & weight
- Typically grows to a length of 13 to 20 cm (5 to 8 inche…
- Diet
- Herbivorous, feeding primarily on benthic filamentous al…
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Physical characteristics
Oval-shaped, compressed body with a vibrant powder blue coloration, a bright yellow dorsal fin, a contrasting white face with a black mask, and white margins on the anal and pelvic fins. It has a retractable scalpel-like spine on each side of the caudal peduncle for defense.
Habitat & distribution
Inhabits shallow, clear coastal coral reefs and surge zones, typically found at depths ranging from 0 to 25 meters across the Indo-Pacific region, from East Africa to Indonesia and the western Pacific.
Behavior
Diurnal, highly active swimmers that are somewhat territorial and aggressive toward other surgeonfish and similar-looking reef species. They often roam the reef individually or in loose feeding aggregations.
Diet
Herbivorous, feeding primarily on benthic filamentous algae and microalgae scraped from hard substrates using its comb-like teeth.
Reproduction
Broadcast spawners that gather in groups to release eggs and sperm into the water column, usually timed with lunar cycles and outgoing currents to disperse the planktonic larvae.
Ecological role
Acts as an important herbivore on the reef, feeding extensively on filamentous algae, which helps prevent algae from overgrowing and smothering the coral ecosystem.
Similar species
Acanthurus nigricans (Xanthopterus/White-cheeked surgeonfish), which has a darker slate-gray body and a white patch rather than a distinct white face mask.
Identification tips
Easily identified by the striking combination of a powder-blue body, brilliant yellow dorsal fin, and white face mask. Look for the scalpel spine near the tail.
Interesting facts
Like other surgeonfish, the Powder Blue Tang gets its family name from the sharp, scalpel-like spines located on either side of the tail base, which can inflict deep cuts if handled carelessly.