Powder Blue Tang - Acanthurus leucosternon

Powder Blue Tang (Acanthurus leucosternon)

The Powder Blue Tang is one of the most recognisable surgeonfish in the marine hobby, prized for its vivid powder-blue body, bold black facial mask, crisp white breast and bright yellow dorsal fin. Native to the Indian Ocean, it inhabits shallow, clear coral reefs, especially reef flats and upper seaward slopes, where it grazes benthic algae either singly or in feeding groups. In aquaria it is an active, high-impact display fish, but it is also known for being more delicate than many other tangs, particularly during acclimation, so it is best suited to well-established systems run by keepers with solid marine experience.

Common Name:
Powder Blue Tang.

Scientific Name (Latin):
Acanthurus leucosternon

Maximum Size:
Up to 23 cm in captivity is a sensible retail reference, with some aquarium references listing around 30 cm as maximum length.

Water Type:
Marine.

Origin / Natural Habitat:
Found across the Indian Ocean, from East Africa and Oman eastwards to the Andaman Sea, western Sumatra, southern Java, Bali, the Cocos-Keeling Islands and Christmas Island. It inhabits shallow, clear coastal and island coral reefs, usually on reef flats and upper seaward slopes.

Water Parameters:
Temperature: 22–26°C
pH Range: 8.1–8.4
Salinity: 1.020–1.025 SG

Temperament:
Semi-aggressive to aggressive, especially towards other tangs or similarly shaped fish. This species can become territorial, particularly if space is limited.

Diet:
Primarily herbivorous / algivorous. In the wild it feeds on benthic algae, particularly small algal growths in crevices. In captivity it should be offered a diet rich in marine algae, nori and herbivore-focused prepared foods, with varied supplementary feeding to support condition.

Minimum Tank Size:
Around 900 litres is the safer long-term recommendation for this species, particularly given its activity level, territorial behaviour and sensitivity. Some hobby references suggest smaller systems, but larger established aquaria are more appropriate.

Behaviour & Activity:
A highly active grazer that spends much of the day swimming and browsing rock surfaces for algae. It may occur singly or in large feeding aggregations in nature, and it needs substantial open swimming space in captivity.

Reef Safe:
Reef Safe 
It is widely considered suitable for reef aquaria, but some supplier guidance notes it may pick at small mobile or sessile invertebrates if underfed. In a reef system, monitor carefully around very small ornamental invertebrates, and ensure the fish is fed consistently with plenty of algae-based foods.

Special Requirements or Care Notes:
Best kept in a well-established marine aquarium with excellent oxygenation, strong water movement, open swimming room and rockwork for grazing and shelter. This species is widely regarded as delicate during acclimation, so stable water quality, quarantine and careful introduction are especially important. Like all surgeonfish, it also has sharp caudal spines near the tail and should be handled carefully.

Suitable for:
Suitable for beginners and experienced aquarists, but broader care references describe it as delicate and requiring extra preparation, so experienced care is the safer overall recommendation.

Availability:
Occasional in trade. It is a well-known species and regularly appears through specialist marine suppliers, but it is not generally treated as one of the more routine beginner tangs. 

All images are a visual representation of the fish you will receive, made to be as accurate as possible. Please note that Mother Nature is a wonderful thing, and variation in patterns and colours will occur — that is part of the unique beauty of these animals.