Melanurus Wrasse
Halichoeres melanurus
The Melanurus Wrasse is a colorful, energetic fish vital for pest control in reef tanks. It demands a spacious aquarium with a thick, fine sand bed for nocturnal hiding and a tight lid to stop jumps.
Water Temperature
24 - 27 °C
pH Value
8.1 - 8.4
Water type
Marine
Tank level
Bottom and middle
Adult size
12 cm
Minimum tank volume
>= 200 L
Minimum group
>= 1
GH
15 - 25 dGH
KH
8 - 12 dKH
Species description
Geographical Origin and Habitat: Widespread in the Western Pacific, from Indonesia and the Philippines to the Solomon Islands and the Great Barrier Reef. Inhabits shallow coastal reefs and lagoons down to 15 meters.
Taxonomy and Morphology: Member of the genus Halichoeres. Features a fusiform body typical of wrasses, reaching up to 12 cm (4.7 inches). Equipped with a small terminal mouth with specialized teeth to catch benthic prey.
Social Behavior: Peaceful and industrious. Spends daytime foraging on live rocks and buries itself completely in the sand at night or when threatened to sleep.
Coloration and Sexual Dimorphism: Exhibits beautiful pink-orange and blue-green horizontal stripes. Adult males show more intense coloration with a prominent dark spot outlined in yellow on the tail base and dorsal fin, which is smaller or absent in females.
Care, breeding and tankmates
Aquarium Setup: Requires a spacious tank of at least 200 liters with a deep sand bed (at least 5-8 cm / 2-3 inches) of fine sand for sleeping and hiding. A tight lid is mandatory to prevent jumps.
Diet and Feeding: Carnivore. Feeds on flatworms, pyramidellid snails, nudibranchs, and small crustaceans. Readily accepts mysis, brine shrimp, and high-quality protein pellets.
Water Quality: Demands stable parameters: temperature 24-27°C (75-81°F), pH 8.1-8.4, specific gravity 1.022-1.025, GH 15-25, and KH 8-12.
Compatibility and Cohabitation: Great community and reef-safe fish. Does not bother corals, but may prey on very small ornamental shrimps or feather dusters.
Aquarium Breeding: Extremely difficult. Pelagic spawners. Larvae require specialized plankton cultures, which are difficult to maintain in home aquaria.
Risks and Diseases: Prone to mouth and skin injuries if forced to bury in coarse gravel or crushed coral rather than fine sand. Susceptible to marine ich.
Geographic Origin and Distribution
Widespread in the Western Pacific, from Indonesia and the Philippines to the Solomon Islands and the Great Barrier Reef. Inhabits shallow coastal reefs and lagoons down to 15 meters.
Origin
Tropical oceans and reefsSouth and Southeast AsiaAustralia, New Guinea, and Oceania
Fish profile
- Temperament
- Territorial
- It is an active, curious, and generally peaceful community fish. It ignores corals and focuses entirely on hunting small benthic creatures. It can be somewhat territorial against other similar-looking wrasses.
- Diet
- Carnivore
- This carnivore requires a varied diet of meaty marine foods. Offer chopped seafood and enriched brine shrimp daily. It is prized for eating parasitic flatworms, bristleworms, and nuisance snails.
- Life expectancy
- 5-7 years
- In captivity, this wrasse has an average lifespan ranging between 5 and 7 years when housed in a suitable aquarium. To ensure maximum longevity, it is crucial to maintain stable biological parameters and provide a rich, varied diet. The presence of a fine sand substrate is vital to prevent stress and fatal injuries during sleep.
- Adult size
- 12 cm
- The catalog's scalar value is 12 cm. The FishBase SPECIES table (v25.04 snapshot) source reports a maximum adult measurement of 14 cm for this species, recorded as total length (TL). The taxonomic record consulted is Halichoeres melanurus (v25.04); male or unsexed record. These figures are not interchangeable: the first is the profile's editorial reference, whereas the second is a published maximum under a specific measurement convention; differences among sources can reflect sex, population, life stage and measuring method.
- Sex ratio
- Solitary
- They exhibit protogynous hermaphroditism, changing from female to male as they mature. Keeping a single specimen or one male with a harem of females is ideal. Two males will almost certainly exhibit lethal aggression towards each other.
- Feeding frequency
- 2-3 times daily
- Feed this active fish at least twice a day to maintain its body weight. Small, frequent meals mirror its natural continuous foraging behavior. An underfed wrasse may become lethargic and lose its vibrant colors.
- Bioload
- Medium
- The Melanurus Wrasse adds a moderate bioload to the aquarium. Its constant swimming and dietary needs result in steady waste production. Robust filtration and routine maintenance are essential to handle this load.
- Flow
- Strong
- It appreciates moderate to high water flow across the reef structure. Dynamic currents help replicate its natural oceanic environment. The flow also keeps the live rock clean, promoting a healthy hunting ground.
- Jump risk
- Yes
- Like all Halichoeres wrasses, it is highly prone to jumping out of the tank. Startling movements or aggressive tank mates can trigger a sudden leap. A secure, custom-fitted lid is an absolute necessity.
- Reproduction
- Oviparous
- Captive breeding is incredibly rare and difficult to accomplish. They spawn in the water column, releasing buoyant eggs that drift with the current. Raising the tiny larvae demands expert care and cultured microscopic zooplankton.
- Compatibility & tankmates
- Reef safe with caution
- It is peaceful towards most fish but poses a risk to small ornamental invertebrates. Corals are generally safe, making it suitable for many reef tanks. It should not be housed with aggressive predators or similar wrasse species.
- Tank level
- Middle/Bottom
- It predominantly occupies the lower to middle sections of the water column. It constantly patrols the live rock and sand interface looking for prey. A sand bed of at least two inches is required for it to bury itself at night.
Scientific Parameters & Models
FishBase
Window to the official scientific data of the species
Data synced on: 06/15/2026
- Trophic level
- 2.9 ± 0.2 se
- Resilience
- High (less than 15 months)
- Phylogenetic uniqueness (PD50)
- 0.5
- Bayesian Length-Weight
- a = 0.01318, b = 3.18
- VulnerabilityLow vulnerability (10 / 100)
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
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