Butterflyfishes of the family Chaetodontidae are conspicuous members of almost all tropical reefs. These colorful fishes have attracted a great deal of attention from both the scientific community and especially the aquarium fish industry. At first one is tempted to say that butterflyfishes are abundant worldwide, but the evidence does not support this statement. The biomass of chaetodontids on reefs may range from 0.02-0.80%, and in terms of numbers they comprise only 0.04-0.61 % of the individuals on the reef. Yet in spite of these relatively small numbers they have been extensively studied. A quick census shows some 170 articles on or about butterfly­ fishes, with 78% of them being published since the 1970's. Along with the cichlids and damselfishes they might be one of the most studied and well published family of tropical fishes. Why then have chaetodontids attracted so much attention? The butterflyfishes are mostly shallow water inhabitants that are approachable and easily recognizable, making their study very feasible. Their bright coloration has provoked many hypotheses but has posed more questions about coloration than it has provided answers. And despite their apparent overall morphological similarity, their highly structured and varied social systems have made them an ideal model for such studies. The reasons for choosing these organisms are indeed as diverse as the studies themselves.