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The butterflyfishes are a group of conspicuous tropical marine fish of the family Chaetodontidae; the bannerfishes and coralfishes are also included in this group. The approximately 120 species in 10 genera〔FishBase ()〕 are found mostly on the reefs of the Atlantic, Indian, and Pacific Oceans. A number of species pairs occur in the Indian and Pacific Oceans, members of the huge genus ''Chaetodon''. Butterflyfishes look like smaller versions of angelfish (Pomacanthidae), but unlike these, lack preopercle spines at the gill covers. Some members of the genus ''Heniochus'' resemble the Moorish idol (''Zanclus cornutus'') of the monotypic Zanclidae. Among the paraphyletic Perciformes, the former are probably not too distantly related to butterflyfish, whereas the Zanclidae seem far less close. ==Description and ecology== Butterflyfishes mostly range from in length. The largest species, the lined butterflyfish and the saddle butterflyfish, ''C. ephippium'', grow to . The common name references the brightly coloured and strikingly patterned bodies of many species, bearing shades of black, white, blue, red, orange, and yellow. Other species are dull in colour. Many have eyespots on their flanks and dark bands across their eyes, not unlike the patterns seen on butterfly wings.〔 〕 Their deep, laterally narrow bodies are easily noticed through the profusion of reef life. The conspicuous coloration of butterflyfishes may be intended for interspecies communication. Butterflyfish have uninterrupted dorsal fins with tail fins that may be rounded or truncated, but are never forked. Generally diurnal and frequenting waters less than deep (though some species descend to ), butterflyfishes stick to particular home ranges. These coralivores are especially territorial, forming pairs and staking claim to a specific coral head. Contrastingly, the zooplankton feeders form large conspecific groups. By night, butterflyfish hide in reef crevices and exhibit markedly different coloration. Their coloration also makes them popular aquarium fish. However, most species feed on coral polyps and sea anemones. Balancing the relative populations of prey and predator is complex, leading hobby aquarists to focus on the few generalists and specialist zooplankton feeders. Butterflyfishes are pelagic spawners; that is, they release many buoyant eggs into the water, which become part of the plankton, floating with the currents until hatching. The fry go through a tholichthys stage, wherein the body of the postlarval fish is covered in large, bony plates extending from the head. They lose their bony plates as they mature.〔 Only one other family of fish, the scats (Scatophagidae) express such an armored stage. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「butterflyfish」の詳細全文を読む スポンサード リンク
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