Butterfly fish

Butterfly fish belong to the Chaetontidae family. They are around four to ten inches long and inhabit coral reefs in shallow tropical seas.

All species of butterfly fish are brightly coloured, have deep bodies and a series of spines in front of both the dorsal and anal fins. These fins curve round the body to meet the tail fin.

Another feature that distinguishes butterfly fish is the pronounced snout, although the size of it varies between species, depending on particular feeding habits. For example, the clown butterfly fish from the tropical Pacific has a relatively short snout whereas that of the forcipiger butterfly fishes is very long.

The mouth parts of the various species also display differences that relate to snout length. Some have pointed long snouts with tiny mouths and protruding teeth that are used to nip off coral polyps, whereas the long-nosed butterfly fish (Forcipiger longirostris) uses its much longer snout to probe gaps in the coral to find burrowing crustaceans and worms.

© John Welford