|
The Acanthuridae are the family of surgeonfishes, tangs, and unicornfishes. The family includes about 82 extant species. The family is composed of marine fish living in tropical seas, usually around coral reefs. Many of the species are brightly colored and popular for aquaria. The distinctive characteristic of the family is the scalpel-like spines, one or more on either side of the tail ("thorn tails"), which are dangerously sharp. The dorsal, anal, and caudal fins are large, extending for most of the length of the body. The small mouths have a single row of teeth used for grazing on algae. Surgeonfishes sometimes feed as solitary individuals, but they also often travel and feed in schools. Feeding in schools may be a mechanism for overwhelming the highly aggressive defense responses of small territorial damselfishes that vigorously guard small patches of algae on coral reefs. Most species are relatively small and have a maximum length of 15–40 cm (6–16 in), but some members of the genus ''Acanthurus'', some members of the genus ''Prionurus'', and most members of the genus ''Naso'' can grow larger, with the whitemargin unicornfish (''N. annulatus''), the largest species in the family, reaching a length of up to . These fishes can grow quickly in aquaria, so average growth size and suitability should be checked before adding them to a marine aquarium. ==Evolution and fossil record== There are several extinct genera known from fossils dating from the Eocene to Miocene: 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「Acanthuridae」の詳細全文を読む スポンサード リンク
|