Lunare Wrasse Care Guide
Thalassoma lunare is a widespread Indo-Pacific reef wrasse with a yellow crescent tail, reaching up to 45 cm.
Compiled by Aquairi from published sources · Published · Updated
Overview
Thalassoma lunare, the moon wrasse, is a marine wrasse of the family Labridae. According to FishBase, it ranges across the Indo-Pacific from the Red Sea and East Africa to the Line Islands, north to southern Japan and south to Lord Howe Island and northern New Zealand. Adults have a green body with marked scales and a blue-to-magenta head; the tail bears a yellow crescent that gives the species its name.
Taxonomy
- Family: Labridae
- Genus: Thalassoma
- Scientific name: Thalassoma lunare (Linnaeus, 1758)
Habitat
FishBase places the moon wrasse on the upper parts of lagoon and coastal reefs and on protected seaward reefs, sometimes entering estuaries, at depths of 1-20 m. Wikipedia notes the fish rests in rock crevices at night and is active throughout the day.
Tank requirements
- Minimum tank volume: 400 L (about 105 gal)
- Temperature: 24-26 °C (75-79 °F)
- pH: 8.1-8.4
- GH: 8-12 °dGH
- Maximum length: about 45 cm TL (FishBase)
- Lifespan: 8-15 years
Diet
The moon wrasse is a carnivore (FishBase trophic level 4.2) that feeds primarily on small benthic invertebrates and fish eggs. Because of this diet it will consume ornamental shrimps and other small invertebrates in an aquarium.
Compatibility
The species is semi-aggressive, active and territorial, described by Wikipedia as moving all day long. It suits robust tank mates such as tangs, sturdy wrasses and cardinalfishes, while overly aggressive triggerfishes should be avoided.
Breeding
FishBase and Wikipedia describe the moon wrasse as a protogynous hermaphrodite; individuals begin as females and change sex at around 11 cm. Spawning groups form leks, typically one dominant male with about a dozen others. Captive breeding is regarded as an expert-level challenge.
Conservation status
IUCN Red List: Least Concern (assessed 2008).
Moon Wrasse Breeding Guide (Thalassoma lunare)
Overview
The moon wrasse (Thalassoma lunare) is a Labridae wrasse native to the Indian Ocean and western Pacific, where it inhabits coral reefs at depths of 1 to 20 m. It can reach 45 cm in total length. Adults have a green body with marked scales and a head ranging from blue to magenta, while the dark juvenile tail blotch develops into the characteristic yellow crescent on maturation.
Sexing
The moon wrasse is a protogynous hermaphrodite that begins life as a female and can later transform into a male. Wikipedia reports that this sex change takes only about ten days for this species. Because individuals shift sex with social context and colour intensifies in dominant males, fixed visual sexing of a given fish is unreliable; the most vivid all-blue colour appears in the breeding-season dominant male.
Spawning Behavior & Trigger
During the breeding season the dominant male becomes completely blue, gathers females, and spawning occurs before high tide. As an oviparous reef wrasse it is a pelagic broadcast spawner, releasing gametes into the water column so fertilised eggs drift away as plankton. The tidal timing is the documented natural trigger; no captive trigger has been established.
Egg & Fry Care
Fertilised eggs are pelagic and develop into planktonic larvae carried in open water. This dispersal-larvae phase is the central obstacle to captive rearing, as the larvae are minute and demand live planktonic food unavailable at scale in a home tank. No home-aquarium fry-rearing data exist for the species.
Common Challenges
The moon wrasse is active, territorial and carnivorous, feeding on fish eggs and small invertebrates, so it is not reef-safe and would consume tankmate spawn. Its large adult size (up to 45 cm) demands a very large system, and the unreared pelagic larval stage closes off home breeding. It remains a wild-caught fish in the trade.