Bluehead Wrasse (Thalassoma bifasciatum)

The Bluehead Wrasse is a vibrant and energetic Caribbean reef fish know for its changing colouration and nonstop activity. Juveniles begin life with a bright yellow body and a distinctive blue stripe along the head, while mature males transform into spectacular shades of electric blue, emerald green, turquoise, and yellow. Constantly weaving through the rockwork in search of food, this intelligent wrasse brings endless movement and natural behaviour to the aquarium. Due to its active nature and eventual size, the Bluehead Wrasse is best suited for larger marine aquariums with plenty of swimming space and robust tankmates.

Suggested parameters

• Temperature: 24–26°C (75–79°F)

• Salinity: 1.025–1.026 SG

• pH: 8.1–8.4

• Alkalinity: 8–10 dKH

• Calcium: 400–450 ppm

• Magnesium: 1250–1400 ppm

• Nitrate: 2–20 ppm

• Phosphate: 0.03–0.10 ppm

Care and temperament

• Difficulty: Easy

• Temperament: Semi-aggressive

• Reef safe: Use caution; generally safe with corals but may prey on ornamental shrimp, feather dusters, small crabs, snails, and other mobile invertebrates

• Minimum tank size: 90 gallons (340 litres)

• Requires plenty of open swimming space along with rockwork for sleeping and shelter

• An active species that appreciates strong water movement and a mature aquarium

• May become dominant as it matures, particularly toward timid wrasses or similarly shaped fish

• A tightly fitting lid is essential, as this species is a powerful jumper

Diet

The Bluehead Wrasse is an opportunistic carnivore with a healthy appetite that readily accepts a wide variety of prepared foods.

• Frozen mysis shrimp

• Enriched frozen brine shrimp

• High-quality marine pellets

• Premium marine flakes

• Occasional live foods can be offered as enrichment

• Feed 2–3 small meals daily to support its active metabolism

Compatibility and tankmates

• Excellent with tangs, angelfish, butterflyfish, larger clownfish, rabbitfish, and other confident community fish

• Can be housed with larger fairy and flasher wrasses in spacious aquariums

• Generally ignores corals

• May prey on ornamental shrimp, feather dusters, tiny crabs, snails, and other small invertebrates

• Avoid very timid fish such as firefish and small dartfish that may become stressed by its constant activity

• Avoid housing with highly aggressive triggers or large predatory fish

Health and acclimation notes

The Bluehead Wrasse is a hardy species that acclimates readily to established marine aquariums. Slow drip acclimation for 45–60 minutes is recommended before introduction. New arrivals typically begin exploring immediately and usually accept frozen foods within a short period. As with all wrasses, a secure lid should be in place before introduction to prevent jumping. Stable water quality and a varied diet will help maintain vibrant colouration and long-term health.

What you are buying

You will receive: 1 Bluehead Wrasse (Thalassoma bifasciatum)

Juveniles display a bright yellow body with a blue facial stripe, while mature males develop an electric blue head with vibrant green, turquoise, and yellow colouration. Colour, pattern, size, and sex may vary naturally depending on age and stage of development.

A mature aquarium with stable water parameters, a lot of swimming space, and secure rockwork is recommended. Slow drip acclimation is encouraged before introduction. The Bluehead Wrasse is an active and rewarding species that adds constant motion and brilliant Caribbean colour to larger marine aquariums.

Why we love it

• Undergoes one of the most dramatic colour transformations of any Caribbean reef fish

• Brilliant blue, green, and yellow colouration creates a stunning display in larger aquariums

• Constantly active, bringing energy and movement to the reef

• Hardy and adaptable, making it an excellent choice for experienced marine hobbyists

• A fantastic showcase fish for larger Caribbean-themed or FOWLR marine aquariums