The Melanurus Wrasse (Halichoeres melanurus), also known as the Tail-Spot Wrasse or Hoeven’s Wrasse, is a vibrant and active marine fish appreciated for its striking appearance and beneficial role in reef aquariums.
Key Information
• Small fish safe: ⚠️Caution
• Small invert safe: ⚠️ Caution
• Coral safe: ✅ Yes
• Minimum tank size: 189 liters (50 gallons)
• Adult size: Up to 11.5 cm (4.5 inches)
• Diet: Carnivorous, feeding on small invertebrates and pests like flatworms and pyramidellid snails.
• Be aware of: May prey on small ornamental invertebrates; requires a sandy substrate for burrowing; known to jump, so a secure lid is essential.
Appearance and Coloration
The Melanurus Wrasse displays a captivating coloration:
• Body Color: Blue-green with horizontal pink or yellow stripes running along its sides.
• Distinctive Markings: Males exhibit more vibrant colors, while females have a small black spot on the first interspinous membrane of the dorsal fin and another between the second and third soft rays.
• Size: Can grow up to 11.5 cm (4.5 inches) in length.
These features make it a visually appealing addition to marine aquariums.
Natural Habitat and Behavior
In the wild, Melanurus Wrasses are found in the western Pacific, from Japan to Samoa and Tonga, and south to the Great Barrier Reef. They inhabit shallow coral reefs and rocky shores, typically at depths up to 15 meters. They are often observed solitary or in small groups over sheltered reefs. Their diet mainly consists of small invertebrates such as polychaetes, copepods, isopods, and forams.
Tank Requirements and Water Parameters
To ensure the well-being of the Melanurus Wrasse in captivity:
• Minimum Tank Size: A 50-gallon (189 liters) aquarium is recommended to provide ample space.
• Water Parameters:
• Temperature: 22°C – 26°C (72°F – 78°F)
• pH: 8.1 – 8.4
• Specific Gravity: 1.020 – 1.025
• Substrate: A sandy bottom of 2-3 inches is essential, as they burrow into the sand when frightened or sleeping.
• Aquascaping: Provide plenty of live rock to create hiding spots and foraging areas, mimicking their natural reef habitat.
• Lighting: Moderate lighting is suitable.
• Water Movement: Moderate flow to simulate their natural environment.
Maintaining stable water conditions and high water quality is crucial for their health. A mature, well-established aquarium will support their natural behaviors and provide necessary shelter.
Diet and Feeding
Melanurus Wrasses are carnivorous and adapt well to captive diets:
• Diet: Offer a varied diet consisting of:
• Vitamin-enriched frozen mysis shrimp
• Vitamin-enriched frozen brine shrimp
• Other meaty foods
• High-quality marine flake and pellet food
They are also known to feed on unwanted pests on live rock, such as flatworms and pyramidellid snails, making them beneficial for reef aquariums.
Compatibility and Social Structure
Melanurus Wrasses are generally peaceful but can exhibit semi-aggressive behavior, especially towards similar species or new tank mates:
• Social Structure: Best kept singly unless in a very large aquarium where multiple individuals can establish territories.
• Temperament: May act aggressively towards peaceful wrasses and other easily intimidated fish, especially if inadequately fed or if the habitat lacks hiding places.
• Compatible Tank Mates: Suitable companions include peaceful community fish such as gobies, blennies, and wrasses. Caution is advised when housing with other wrasses or species with similar coloration.
Observing their interactions and providing ample space can help mitigate aggressive behaviors. Due to their territorial nature, they should be housed with non-aggressive tank mates to prevent stress.
Important Considerations
• Reef Compatibility: Considered reef-safe, they should leave corals and other beneficial invertebrates alone. They may even help control pyramidellid snail populations if you’re having problems with these snails and your clams.
• Acclimation: They may be shy upon introduction but typically become more confident over time.
• Health: Ensure a varied diet and stable water conditions to prevent common health issues.
• Jumping Behavior: Known to be jumpers, so a covered aquarium is essential to prevent escape.
With proper care and attention to their specific needs, Melanurus Wrasses can be a vibrant and beneficial addition to a marine aquarium.