Thin, deep-bodied and marked to break up the outline, usually in pairs that stay together for years. A bar through the eye and a false eyespot near the tail is the commonest arrangement, and it works: a predator strikes at the wrong end.
Most are coral feeders and several eat one coral genus and nothing else. That is the practical fact about them: a butterflyfish is where its food is, and the specialists are the first to go when the coral does. The generalists that also take worms and small invertebrates are the ones still common on a degraded reef.
The pairs are worth watching rather than counting. They feed a body-length apart, turn together, and a fish alone is usually a fish whose partner is behind a coral head. A photograph of two is easier to get than it looks, because they will not leave each other.
Bannerfish and the Moorish idol are filed here and are not the same thing. The bannerfish are butterflyfish; the Moorish idol is not, and is closer to the surgeonfish.
Every one has a page. They are shown as a list rather than as pictures because nothing has been photographed or logged for them yet, and a species with nothing behind it should not sit in front of one that has.
How many of the 35 carry a record at each destination. A species usually carries several, so these do not add up to 35.
All 1316 species in one index, with filters for destination, rarity and hazard.
