Convict Tang

Also known as the Convict Surgeonfish or Acanthurus triostegus
The Convict Tang is a striking reef tang distinguished by its clean white body with bold black vertical stripes resembling a classic convict uniform. Native to the Indo-Pacific region, including Hawaii, Fiji, and the Great Barrier Reef, this hardy and active tang is popular among aquarists for its algae-grazing abilities and peaceful yet alert temperament. Captive-bred Convict Tangs adapt well to aquariums and are an excellent choice for both intermediate and advanced reef hobbyists.

Key Features

• Scientific Name: Acanthurus triostegus
• Common Names: Convict Tang, Convict Surgeonfish, Striped Surgeonfish
• Adult Size: 6–10 inches (15–25 cm)
• Lifespan: 7–12+ years with proper care
• Temperament: Peaceful with most species but may show territorial behavior toward other tangs
• Reef Compatibility: Reef-safe 
• Minimum Tank Size: 125 gallons 
• Experience Level: Intermediate

Habitat & Tank Requirements

Natural Habitat: Found on coral-rich reef flats, lagoons, and seaward reef slopes at depths of 3–100 feet. Primarily feeds on filamentous algae.

Tank Environment:

• Extensive live rock for grazing and hiding
• Open swimming areas for active movement
• Moderate water flow to mimic natural currents
• Established, stable 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

Convict 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 with most species but may show 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
• Excellent choice for mixed reef 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 grazing and swimming
• Clear eyes and smooth fins
• Vibrant, uniform coloration with sharp stripes

Color & Development

Coloration Characteristics:

• Body: White with 5–6 bold black vertical stripes
• Fins: Transparent to slightly gray with faint black markings
• Eyes: Clear and bright

Color Intensity:

• High-quality diet maintains bright stripes
• Proper lighting enhances black/white contrast
• Stress or poor water quality may cause temporary fading

Size & Growth:

• Juveniles start at 2–3 inches
• Reach adult size (6–10 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.

Breeding Potential

Breeding Convict Tangs in captivity is rare. Spawning may occur in large, mature reef systems with optimal conditions, abundant grazing surfaces, and stable water quality. Raising larvae is complex and generally requires professional facilities.

Why Choose a Quarantined Convict Tang?

A fully quarantined Convict Tang offers better long-term success, fewer health issues, stronger feeding habits, and a smoother transition into your display tank, giving you confidence that your new tang will thrive in your reef system.