Distinctive Characters: Dorsal fin with 8 spines and 13 rays. Anal fin with 3 spines and 11 rays. Pectoral fin with 15 rays. Body depth 3.1-3.7 in standard length. Caudal fin varying from truncate in juveniles to lunate with filamentous lobes in large males.
Colour: Females dark green, with fine red stripes on sides and red bands on chest and head. Yellow crescent on caudal fin. Males similar but background - colour more blue than green.
Habitat and Biology: Common on coral and rocky reefs to depths of 20 m. Feeds on benthic invertebrates, small fishes and fish eggs.
Remarks: Thalassoma lunare is a very common and wide-ranging species in Maldivian reefs. It is very bold and will readily approach divers and snorkellers if food is being handed out.