Lieutenant Tang

Lieutenant Tang Overview

• Common Name: Lieutenant Tang

• Scientific Name: Acanthurus tennentii

• Also Known As: Tennent’s Tang, Doubleband Surgeonfish

• Family: Acanthuridae (Surgeonfish/Tangs)

• Origin: Indian Ocean to Western Pacific – including Maldives, Sri Lanka, Indonesia

• Size: Up to 10 inches (25 cm)

• Lifespan: 8–15 years in captivity with proper care

🌈 Appearance

• Body Color: Bluish-gray to olive base with a distinctive dark vertical band behind the eye and a lighter vertical band just behind it (hence "lieutenant")

• Tail Fin: Can have a blue or white margin

• Scalpel: Like all tangs, they have a sharp defensive spine near the base of the tail

• Juveniles: More brownish or dull with less defined banding

🏝️ Natural Habitat

• Found in lagoon and reef slope areas

• Grazes constantly on algae and biofilm

• Often seen singly or in small groups in the wild

🐠 Aquarium Care

Tank Requirements:

• Minimum Tank Size: 125 gallons (475+ liters) — needs lots of swimming space

• Aquascape:

  • Large open areas for swimming

  • Plenty of live rock for grazing and shelter

• Water Movement: Moderate to strong

• Lighting: Moderate to high (helps support algae growth)

Water Parameters:

• Temperature: 74–80°F (23–27°C)

• pH: 8.1–8.4

• Salinity: 1.023–1.025

• Nitrates: <20 ppm preferred

• Stability: Highly important — tangs can be sensitive to parameter swings

🍽️ Diet

• Feeding Type: Herbivore (will accept omnivore foods)

• Diet:

  • Primarily marine algae and seaweed (nori sheets)

  • Spirulina-based flakes and pellets

  • Frozen herbivore blends

  • Occasional mysis or brine shrimp

• Feeding Frequency: 2–3 times daily

• A well-fed tang is less aggressive and more resistant to disease

🤝 Behavior & Compatibility

• Temperament: Generally peaceful for a tang, but can be territorial with other tangs

• Reef Safe: ✅ Yes — won’t harm corals or most inverts

• Tankmates:

  • Peaceful to semi-aggressive fish

  • Avoid other Acanthurus tangs unless in a large tank

  • Can mix with tangs of different genus (e.g., Zebrasoma, Ctenochaetus) in very large systems

  • Works well in reef communities with clownfish, wrasses, anthias, etc.

✅ Pros

• Beautiful, bold pattern

• Active swimmer — adds movement to the tank

• Excellent algae grazer

• Generally hardy once established

• Reef safe

❌ Cons

• Needs a large tank due to size and swimming needs

• May become territorial with other tangs

• Prone to marine ich (Cryptocaryon) — quarantine is strongly recommended

• Requires frequent feeding to prevent aggression and stress

💡 Tips for Success

• Use a seaweed clip with nori daily to satisfy grazing needs

• Introduce to the display tank after more aggressive tangs, if mixed

• Keep stress low with stable water and high oxygen levels

• Provide UV sterilization or ozone for disease prevention

• Quarantine all new additions to avoid parasites

Summary