Description

Yellow Lunar Wrasse

The “yellow lunar wrasse” is a common name for two similar species of wrasse: the Moon Wrasse (Thalassoma lunare) and the Green Moon Wrasse (Thalassoma lutescens). They are both known for their vibrant colors and are popular in the aquarium trade.

Moon Wrasse (Thalassoma lunare)
Appearance: Adults are typically green with a distinct, crescent-shaped yellow patch on their tail fin, which gives them the name “moon wrasse.” They also have vertical red lines on their scales and a head with blue, magenta, and pink markings. Juveniles are blue on the lower half of their body and have a black spot on the dorsal fin and a black blotch on the caudal fin base.

Habitat: Native to the Indo-Pacific, from the Red Sea and East Africa to the western Pacific Ocean. They inhabit coral reefs and surrounding areas at depths from 1 to 20 meters.

Behaviour: They are diurnal, very active, and can be territorial. They are carnivores, feeding on small invertebrates like crabs, shrimps, and fish eggs. At night, they seek shelter in rock crevices or bury themselves in the sand to sleep.

Life Cycle: This species is a protogynous hermaphrodite, meaning all individuals are born female and can change sex to male as they mature. The process of sex change can be as quick as 10 days.

Green Moon Wrasse (Thalassoma lutescens)
Appearance: This species is also known as the yellow-brown wrasse. The body is primarily yellow with wavy orange to reddish lines on the head and a reddish-orange vertical mark on each scale. The pectoral fins are yellow with blue tips.

Habitat: Widespread in the Indo-Pacific, from Sri Lanka to the Kermadec Islands in New Zealand. They live in outer lagoon and seaward reefs, often in areas with rich coral, sand, and rubble.

Behaviour: They are carnivorous and feed on a variety of benthic invertebrates. They can be territorial and are known to live in groups or alone.

Life Cycle: Like the Moon Wrasse, they are also protogynous hermaphrodites, with all individuals starting as females and some changing to males.

Aquarium Care
Both species are known for being hardy and are sought after for home aquariums due to their bright colors and active behavior. They are considered semi-aggressive and are not considered “reef-safe” as they may eat smaller invertebrates. It’s recommended to keep them in a larger tank (125 gallons or more) with plenty of rocks for hiding and with larger, aggressive tank mates. They should be added to the tank last to minimize aggression toward other fish. They are also known to jump out of uncovered aquariums.