Lieutenant Tang

Also known as the Lieutenant Surgeonfish, Doubleband Surgeonfish, Tennenti Tang.

The Lieutenant Tang is a striking reef tang recognized for its vibrant blue face, olive-brown body, and distinct yellow markings near the dorsal and caudal fins. Native to the Indo-Pacific region, including the Great Barrier Reef, Fiji, and Micronesia, this tang is active, peaceful, and hardy, making it a popular choice among intermediate and advanced aquarists. Captive-bred specimens adapt well to aquarium life, displaying vivid coloration and energetic swimming behavior in reef or FOWLR systems.

Key Features

Scientific Name: Acanthurus tennenti
Common Names: Lieutenant Tang, Doubleband Surgeonfish, Tennenti Tang
Adult Size: 9–12 inches (23–30 cm)
Lifespan: 8–12+ years with proper care
Temperament: Generally peaceful but may show territorial behavior toward other tangs
Reef Compatibility: Reef-safe 
Minimum Tank Size: 180 gallons
Experience Level: Intermediate 

Habitat & Tank Requirements

Natural Habitat: Found on coral-rich reef slopes, lagoons, and coastal reefs across the Indo-Pacific. Feeds primarily on filamentous algae.

Tank Environment:

• Open swimming areas essential for active tang behavior
• Moderate water flow to mimic natural currents
• Plenty of live rock for grazing and shelter
• Established aquariums recommended (3+ months)

Water Parameters:

• Temperature: 74–82°F (23–28°C)
• Salinity: 1.023–1.025 specific gravity
• pH: 8.1–8.4
• Ammonia/Nitrite: 0 ppm
• Nitrate: <20 ppm
• Alkalinity: 8–12 dKH

Essential Equipment:

• Efficient protein skimmer
• Strong filtration system
• Stable lighting suitable for reef or FOWLR setups
• Regular water changes (10–15% weekly)

Diet & Feeding

Lieutenant Tangs are primarily herbivorous but will accept prepared foods once acclimated.

Recommended Foods:

• Pellets/Flakes: Algae-based, spirulina, herbivore formulas
• Frozen Foods: Finely chopped marine algae, phytoplankton
• Plant Matter: Nori sheets, spirulina sheets
• Prepared Mixes: Herbivore blends, enriched frozen preparations

Feeding Schedule:

• Feed 2–3 times daily
• Offer portions they can consume in 2–3 minutes
• Variety ensures healthy digestion and vibrant coloration

Behavior & Compatibility

Temperament: Peaceful but may exhibit territorial behavior toward other tangs

Tank Mates: Compatible with most peaceful reef fish including gobies, wrasses, blennies, and non-aggressive tangs. Caution with aggressive tangs or predatory species.

Pairing Behavior: Can be kept singly or in groups in large aquariums. Juveniles adapt more readily to community environments.

Reef Compatibility

• Completely reef-safe; will not harm corals or invertebrates
• Suitable for mixed reef or FOWLR aquariums

Acclimation & Care Tips

Initial Acclimation:

• Drip acclimation over 45–60 minutes
• Float bag for temperature equalization (15–20 minutes)
• Dim lights during introduction

Health Considerations:

• Susceptible to marine ich (Cryptocaryon) if stressed
• Quarantine for 2–3 weeks before adding to display tank

Signs of a Healthy Specimen:

• Active swimming and grazing
• Clear eyes and smooth fins
• Vibrant body coloration with striking blue face

Color & Development

Coloration Characteristics:

• Body: Olive-brown with subtle blue striping
• Fins: Yellow accents on dorsal and caudal fins
• Face: Bright blue with distinctive markings
• Eyes: Clear and bright

Color Intensity:

• High-quality diet maintains vivid coloration
• Proper lighting enhances blue and yellow contrast
• Stress or poor water quality may cause temporary fading

Size & Growth:

• Juveniles start at 3–4 inches
• Reach adult size (9–12 inches) within 12–18 months

Special Considerations

Quarantine is Recommended: Observed for parasites and disease, monitored for appetite and activity, conditioned to prepared aquarium foods.

Captive-Bred Advantages:

• Better adaptation to aquarium life
• Reduced disease risk
• More consistent coloration
• Stronger feeding habits

Breeding Potential:

Breeding Lieutenant Tangs in captivity is rare. Successful spawning typically occurs only in large-scale or professional reef setups with optimal water quality and abundant grazing surfaces.

Why Choose a Quarantined Lieutenant Tang?

A fully quarantined Lieutenant Tang ensures long-term health, fewer stress-related issues, and smooth acclimation into your display tank. Captive-bred, healthy specimens showcase brilliant blue, yellow, and olive-brown coloration, providing an active, visually striking centerpiece for your reef or FOWLR aquarium.