Rainbow wrasse

A long, slim, almost cigar-shaped wrasse that never seems to stop moving. Young fish and females are brown or reddish on the back with a bold white or pale yellow stripe running the length of the flank and a white belly. Big males are unmistakable: green to blue-grey with a bright orange zigzag stripe running from head to tail, a dark blue-black patch just behind the pectoral fin, and the first few dorsal rays drawn out into a small orange and black flag.

It works the rock and rubble at speed, picking off tiny snails, shrimp, worms and urchin fragments, and is one of the first fish to arrive when anything on the bottom gets disturbed. Females usually run 12 to 18 cm and males up to about 25 cm, with 30 cm the outside limit.

Around Malta and Gozo you will find it on almost every rocky dive from three metres down past thirty, and it is especially thick over broken rubble and the sandy edges of reef. At dusk, and whenever it is frightened, it dives head-first into the sand and buries itself, which is why the site can look empty of them the moment you switch on a torch.