Atlantic Blue Tang (Adult)

Also known as the Caribbean Blue Tang or Doctorfish.
The Atlantic Blue Tang is a stunning surgeonfish native to the warm tropical waters of the Caribbean and Western Atlantic. While juveniles display a vibrant yellow coloration, adults transform into deep cobalt blue with subtle facial markings and a distinct scalpel at the base of the tail. Active, hardy when acclimated, and constantly grazing, this species adds beauty, movement, and personality to large reef aquariums. A quarantined adult specimen adapts more easily and thrives in well-maintained systems with plenty of swimming space.

Key Features

Scientific Name: Acanthurus coeruleus
Common Names: Atlantic Blue Tang, Caribbean Blue Tang, Blue Doctorfish
Adult Size: 8–10 inches (20–25 cm)
Lifespan: 10–12+ years with proper care
Temperament: Semi-aggressive; territorial with similar-shaped tangs
Reef Compatibility: Reef-safe – will not harm corals or invertebrates
Minimum Tank Size: 125 gallons (180+ gallons recommended)
Experience Level: Intermediate to Advanced – needs stable water, space, and constant grazing

Habitat & Tank Requirements

Natural Habitat:
Found across the Caribbean Sea, Florida reefs, Bermuda, and the Gulf of Mexico. Adults reside on rocky outcrops, shallow reefs, and areas with abundant algae growth.

Tank Environment:

• Large open swimming space
• Mature tank with natural rockwork
• Constant availability of algae or grazing surfaces
• High oxygen levels and strong flow
• UV sterilizer recommended for parasite prevention

Water Parameters:

• Temperature: 74–80°F (23–27°C)
• Salinity: 1.023–1.025
• pH: 8.1–8.4
• Ammonia/Nitrite: 0 ppm
• Nitrate: <15 ppm
• Alkalinity: 8–12 dKH

Essential Equipment:

• Oversized protein skimmer
• High-flow pumps or gyres
• UV sterilizer
• Auto-top-off for salinity stability
• 10–15% weekly or 20% biweekly water changes

Diet & Feeding

Atlantic Blue Tangs are herbivores that graze throughout the day. A varied diet is essential for color, immunity, and digestive health.

Recommended Foods:

• Nori (green, red, brown varieties)
• Spirulina-rich pellets and flakes
• Marine algae sheets
• Frozen herbivore blends
• Occasional mysis or brine shrimp for variety
• Vitamin and garlic-enriched foods

Feeding Schedule:

• Feed 2–3 times daily
• Keep a nori clip available
• Provide mixed foods to support long-term health

Behavior & Compatibility

Temperament:
Active, bold, and territorial toward similar-shaped tangs, especially other Acanthurus species. Generally peaceful with most reef-safe fish.

Tank Mates:
Compatible with:

• Wrasses
• Gobies
• Blennies
• Anthias
• Chromis
• Peaceful community fish

Caution with:

• Other tangs of similar body shape
• Surgeonfish added after the Atlantic Blue Tang

Avoid:

• Aggressive triggers
• Large groupers
• Multiple adults in small tanks

Color & Development

Coloration Characteristics:

• Deep cobalt blue body
• Subtle dark facial lines
• Blue-edged fins
• White or pale blue caudal spine (scalpel)

Color Intensity:
Color deepens with proper algae-rich diet, stable water, and low stress.

Size & Growth:
Juveniles start as bright yellow, transitioning to blue as they age. Adults reach 8–10 inches and need ample swimming space.

Acclimation & Care Tips

Initial Acclimation:

• Drip acclimate for 45–60 minutes
• Float bag for temperature equalization
• Dim lights during introduction
• Offer nori immediately to encourage feeding
• Reduce aggression with acclimation boxes if needed

Health Considerations:
May be prone to:

• Marine ich (Cryptocaryon)
• Marine velvet (Amyloodinium)
• Lymphocystis
• HLLE if diet or water quality is poor

Quarantined adults adapt far more reliably.

Signs of a Healthy Specimen:

• Active, constant swimmer
• Strong appetite
• Clear eyes
• Smooth fins with no tears
• Deep, even blue coloration
• No flashing or labored breathing

Special Considerations

Quarantine is Recommended:
Wild-caught Atlantic Blue Tangs are often exposed to parasites and stress during collection. Dr Reef’s strict quarantine ensures:

• Several weeks of observation
• Preventative treatments when needed
• Transition to prepared foods
• Stabilization before shipment

Breeding Potential

Breeding the Atlantic Blue Tang in home aquariums is extremely rare due to their need for open-water spawning, large groups, and precise environmental conditions. While they may exhibit natural social behaviors, successful spawning events are not typically seen in captivity.

Why Choose a Quarantined Atlantic Blue Tang?
A quarantined specimen is healthier, hardier, and better prepared for life in an aquarium. Proper conditioning dramatically increases survival, reduces disease risk, and makes acclimation smoother for this active and striking species.