Green with six dark bars over the back and a yellow head, on Indian Ocean reef flats and rubble.
To about 20 cm, and most are under 15. Pale green with six dark bars, four on the body and two as saddles over the tail base. Large adults develop pink bands radiating from the eye. Breeding males show a black spot in the middle of the tail fin.
Count the bars and the identification is finished. No other Maldivian Thalassoma carries six discrete dark bars on pale green.
The behaviour worth knowing is that it uses an anvil: it carries hard-shelled prey to a chosen rock, bashes it open, and comes back to the same rock. It works a home range of over a thousand square metres and feeds on planktonic and benthic crustaceans, foraminiferans, small fish, eggs and larvae.
Nought to fifteen metres or a little more, on shallow lagoon and seaward reef, slopes and drop-offs. Common in the aquarium trade.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.