Seemingly advertising themselves with the bold colours on their disk-like bodies, Butterflyfishes are amongst the most conspicuous fishes that swim out openly on coral reefs. They are admired by snorkelers and divers, and are also amongst the most popular and sought after fishes for the marine aquarium. Over 130 species of butterflyfishes and bannerfishes occur in tropical seas around the world. Most live at shallow depths, but a few species were observed from submersibles at about 200 m, too deep for an amateur diver. Photographs of such species in situ are included here.