Acanthurus japonicus (Powder Brown Tang / Whitecheek Tang)
• Small fish safe: ✅ Yes
• Small invert safe: ✅ Yes
• Coral safe: ✅ Yes
• Minimum tank size: 450L+
• Adult size: ~20-22 cm
• Diet: Herbivorous (marine algae, seaweed, spirulina-based flakes/pellets, occasional meaty foods)
• Be aware of: Prone to stress and marine ich. Can be territorial towards other tangs. Requires pristine water quality and a high-fiber diet. Not recommended for beginners.
Powder Brown Tang (Acanthurus japonicus) – A Beautiful but Delicate Surgeonfish
The Powder Brown Tang, also known as the Whitecheek Tang, is one of the most elegant and visually stunningmembers of the Acanthurus genus. Native to the Indo-Pacific region, this species is highly active, constantly grazing on algae, and a standout in reef aquariums. However, due to its sensitivity to stress and disease, it requires experienced care and a well-maintained environment to thrive.
Appearance and Coloration
The Powder Brown Tang is often confused with the Whitecheek Tang (Acanthurus nigricans), but the two species have notable differences:
• Body: The Powder Brown Tang has a rich brown-to-grayish body with a lighter underbelly.
• Face: A bright white patch is present just behind the eyes.
• Fins:
• The dorsal fin has a vibrant yellow stripe, contrasting against the dark body.
• The tail fin is edged in a bright blue outline, adding to its striking appearance.
• The pectoral fins often have a subtle orange or reddish tint.
These colours become more vivid in a stress-free, well-fed specimen, making it one of the most striking tang species in the hobby.
Natural Habitat and Behaviour
Powder Brown Tangs are found in shallow coastal reefs and lagoon areas throughout the Indo-Pacific, including Japan, Indonesia, and the Philippines. They are:
• Constant grazers, feeding on macroalgae and detritus in the wild.
• Fast swimmers, requiring strong currents and open space.
• Moderately aggressive, but can become territorial towards other tangs, especially in smaller tanks.
They are best suited for larger reef tanks with plenty of swimming space and live rock for natural grazing.
Tank Requirements and Water Parameters
Since Powder Brown Tangs are active swimmers and prone to stress, they require a large, well-maintained aquariumwith high water quality.
• Minimum tank size: 450L+ (600L+ recommended for long-term care)
• Temperature: 23–26°C
• pH: 8.1–8.4
• Salinity: 1.020–1.025
• Water movement: Moderate to strong, mimicking reef currents
• Filtration: Strong filtration and protein skimming required to maintain water quality
Because they graze constantly, tanks with natural algae growth and live rock are highly beneficial.
Diet and Feeding
Powder Brown Tangs are primarily herbivores, feeding on macroalgae, diatoms, and detritus in the wild. In captivity, they require a high-fiber diet rich in marine vegetation.
Recommended foods include:
• Dried seaweed (Nori) – Essential for digestion and overall health.
• Spirulina-based flakes and pellets – Helps maintain coloration and immune function.
• Fresh macroalgae – Such as chaetomorpha or gracilaria.
• Occasional meaty foods – Enriched mysis shrimp or brine shrimp (as a supplement only).
They should be fed multiple times per day, as they are constant grazers. A lack of algae in their diet can lead to nutritional deficiencies, stress, and aggression.
Compatibility and Tank Mates
Powder Brown Tangs are semi-aggressive, particularly towards other tangs and surgeonfish. However, they can be peaceful with non-tang species in a well-planned community tank.
Best tank mates include:
✔ Clownfish
✔ Wrasses (Fairy Wrasses, Halichoeres species)
✔ Gobies and blennies
✔ Angelfish (both dwarf and large species)
✔ Other peaceful to semi-aggressive reef-safe fish
Avoid housing with:
❌ Other Acanthurus tangs (e.g., Powder Blue Tang, Whitecheek Tang, Sohal Tang) unless in a very large system.
❌ Aggressive tang species (e.g., Sohal Tang, Clown Tang).
❌ Slow-moving or delicate fish that may struggle to compete for food.
If keeping multiple tangs, they should be introduced simultaneously in a large system to minimize territorial disputes.
Health and Disease Considerations
Powder Brown Tangs are prone to stress-related illnesses, particularly:
• Marine ich (Cryptocaryon irritans) – One of the most ich-prone tang species; quarantine before introduction is highly recommended.
• Head and Lateral Line Erosion (HLLE) – Often caused by poor diet, vitamin deficiencies, or low water quality.
• Nutritional deficiencies – If not fed a varied diet rich in algae, they may become weak or lose colour vibrancy.
To prevent disease and stress-related issues:
✔ Provide a stress-free environment with plenty of swimming space.
✔ Ensure a diet rich in marine algae and vitamins.
✔ Maintain stable, high-quality water parameters.
✔ Quarantine new additions before introducing them to the display tank.
Lifespan and Long-Term Care
With proper care, Powder Brown Tangs can live up to 10-12 years in captivity. Their sensitive nature, dietary needs, and aggression potential make them best suited for experienced marine aquarists.
Why Choose a Powder Brown Tang?
✔ Incredibly striking coloration – Deep brown body, white cheek, and vibrant yellow and blue accents.
✔ Excellent algae grazer – Helps control nuisance algae in reef tanks.
✔ Active and intelligent – Constantly swimming and engaging with its environment.
✔ A showpiece fish – Stands out in large marine aquariums.
⚠ Important Considerations Before Buying a Powder Brown Tang:
🚫 Not for beginners – Requires stable water conditions and experienced care.
🚫 Prone to marine ich – Needs a proper quarantine process and stress-free environment.
🚫 Moderately aggressive – Can become territorial towards other tangs, especially in smaller tanks.