Labridae

Moon wrasse

Thalassoma lunare

At eleven centimeters some females complete their transformation into males

• Blue
• Green
• Orange
• Red
• Cross-climate
• Subtropical
• Tropical
• Regional distribution
• Marine fish
• Fusiform
• Compressed cross-section
• Medium
• Tropical fish

Emerald-green flanks and an incandescent crescent tail give the moon wrasse one of the most radiant profiles on tropical Indo-Pacific reefs. The body displays a vibrant blue-green sheen marked by fine vertical purplish lines across individual scales, while the head is patterned with sweeping magenta and azure facial bands. Its common name stems from the distinctive caudal fin, where a bright canary-yellow central wedge is framed by prolonged reddish-violet outer lobes. Distributed widely from the Red Sea and East Africa across northern Australia and the Great Barrier Reef to the Line Islands, it patrols shallow lagoons, seaward slopes, and surge channels down to twenty meters depth. Constantly in motion, this agile diurnal carnivore uses prominent canine teeth to pick off small benthic crabs, molluscs, brittle stars, and fish eggs. Like many labrids, it is a protogynous hermaphrodite; initial-phase females can transform into intensely colored territorial terminal males when social hierarchies shift. Maximum recorded total length reaches thirty centimetres.

Sources: Australian Museum — Moon Wrasse, Thalassoma lunare