Acanthurus leucosternon

Powder Blue Tang

Scientific Classification

Kingdom:Animalia

Phylum:Chordata

Class:Actinopterygii

Order:Acanthuriformes

Family:Acanthuridae

Genus:Acanthurus

Species:leucosternon

IUCN Status:Least Concern

Quick Stats

Difficulty

Hard

Environment

Saltwater

Temperature

24°C - 28°C

pH Level

8.1 - 8.4

Water Hardness

143 - 214 ppm

Lifespan

10 years

Origin

Indian Ocean

Adult Size

20 - 23 cm

Diet

Herbivore

Creature Type

Fish

TDS

35000 ppm

Water Flow

High Flow

Aquarium Building Information

Minimum Tank Size

480L

Swimming Zone

all levels

Oxygen Consumption

High

Waste Production

High

Metabolism Rate

High

Activity Level

Very Active

Feeding Frequency

Multiple times daily

Food Types

Algae

Vegetables

Pellets

Flakes

Frozen Food

About This Species

Basic Description

The Powder Blue Tang is a strikingly beautiful but challenging saltwater fish, prized for its vibrant appearance and active swimming throughout the aquarium. This very active species requires a large, mature aquarium with ample open space to accommodate its constant movement. As a primarily plant-eating fish, its diet should consist mainly of marine algae and vegetable-based foods, which it needs to graze on frequently throughout the day. Due to its high metabolism, it produces a significant amount of waste, demanding a powerful filtration system and pristine water conditions to thrive. This tang is known for its territorial nature, especially towards other fish with a similar shape and size, and is best kept as the only one of its kind in a tank. Due to its specific needs for diet, space, and water quality, as well as its susceptibility to stress, this fish is recommended only for experienced marine aquarists who can provide a stable and suitable environment. Proper care is essential for this magnificent animal to live a long and healthy life in captivity.

Detailed Description

The Powder Blue Tang is a highly sought-after but demanding species best suited for veteran marine aquarists. In its natural habitat across the Indian Ocean, it inhabits shallow, clear reef flats and slopes with strong water movement. Replicating this environment is key to its success in captivity. A very large and long aquarium is not just a recommendation but a necessity, allowing for the vast, open swimming lanes this incredibly active fish requires. Strong, turbulent water flow is crucial, as it mimics its native currents and ensures the high levels of oxygenation needed to support its high-energy lifestyle and metabolism.

Physiologically, this tang is a dedicated grazer. Its diet in the wild consists of filamentous algae and biofilm found on rocks and substrate. In an aquarium, this behavior must be supported with multiple daily feedings of high-quality, marine-based herbivorous foods. Dried marine algae (nori) clipped to the rockwork is essential, allowing the fish to graze continuously as it would naturally. This should be supplemented with prepared foods like pellets, flakes, and frozen formulas specifically for herbivores. A well-established tank with healthy live rock can also provide a natural foraging ground.

This species' social behavior is a critical consideration. It is aggressively territorial, particularly towards other surgeonfish and any fish with a similar body shape or feeding habits. It is almost always recommended to keep it as a solitary specimen of its genus unless the aquarium is of an exceptionally large, commercial scale. Introducing the tang last into the community can sometimes temper aggression, but its innate territorial drive remains. Due to its high metabolism and constant feeding, it produces a substantial amount of waste, placing a heavy load on the filtration system. Therefore, an oversized protein skimmer, a capable biological filter, and a rigorous schedule of large, regular water changes are non-negotiable to maintain the stable, pristine water parameters it demands. Its sensitivity to common marine parasites, particularly during acclimation, further cements its status as a fish for experts only.

Scientific Description

Acanthurus leucosternon, a member of the family Acanthuridae, is a prominent surgeonfish native to the coral reefs of the Indian Ocean. Its morphology is characterized by a deeply compressiform body, an adaptation that allows for exceptional agility and maneuverability within complex reef structures. Like all members of its genus, it possesses a distinguishing feature: a sharp, scalpel-like spine located on the caudal peduncle, which it can erect for defense against predators or during intraspecific territorial disputes. This spine is a key defensive and agonistic tool. Ecologically, A. leucosternon is a diurnal herbivore, playing a significant role as a primary consumer in its ecosystem. Its feeding behavior involves actively grazing on benthic turf algae and biofilm, which helps control algal proliferation on reefs, thereby preventing the smothering of corals and maintaining overall reef health. This constant grazing activity is supported by a high metabolic rate, which in turn necessitates high oxygen levels in its environment, typically found in the high-energy surge zones of the reef crest and flats. Its IUCN Red List status as 'Least Concern' reflects a widespread distribution and relatively stable population; however, local populations can be impacted by habitat degradation and collection pressures for the ornamental fish trade. In a captive setting, its high metabolic output leads to substantial nitrogenous waste production, resulting in a significant bioload factor that must be managed with robust life support systems. Its innate solitary and territorial behavior is an expression of resource guarding, a common strategy among reef herbivores to secure a reliable food patch.

Breeding Description

Successfully breeding the Powder Blue Tang in a home aquarium is considered unattainable for the hobbyist. There are no reliably documented cases of reproduction in captivity outside of a few highly advanced commercial aquaculture facilities. This significant difficulty stems directly from the species' complex reproductive strategy in the wild. In its natural environment, this species is a broadcast spawner. This process involves the gathering of individuals which then release gametes—eggs and sperm—directly into the water column. Fertilization occurs externally, and the resulting eggs drift in the open ocean as part of the plankton. There are no visible external characteristics to reliably differentiate males from females, making the establishment of a potential breeding pair in an aquarium an impossible task based on guesswork. The primary challenge lies in its extended and delicate pelagic larval stage. After hatching, the microscopic larvae drift with ocean currents for a prolonged period. During this time, they require specific, microscopic planktonic foods which are exceptionally difficult to culture and provide in the correct density in a captive system. The environmental cues needed to trigger spawning, such as lunar cycles, temperature shifts, and social dynamics, are also poorly understood and nearly impossible to replicate in a home aquarium. Therefore, all specimens available in the aquarium trade are wild-collected or, in very rare instances, aquacultured in specialized commercial operations. The focus for any aquarist keeping this species should be solely on providing exceptional long-term care for the individual animal, not on attempting reproduction.

Acanthurus leucosternon

Scientific Classification

Quick Stats

Aquarium Building Information

About This Species

Generate Printable Card