| 翻訳と辞書 |
| right whale dolphin ： ウィキペディア英語版 |
right whale dolphin
Right whale dolphins are cetaceans belonging to the genus ''Lissodelphis''. It contains the northern right whale dolphin (''Lissodelphis borealis'') and the southern right whale dolphin (''Lissodelphis peronii''). These cetaceans are predominantly black, white beneath, and one of the few without a dorsal fin or ridge. They are smaller members of the delphinid family, oceanic dolphins, and very slender. Despite scientists being long acquainted with the species (the Northern species was identified by Peale in 1848 and the Southern by La Cépède in 1804), little is known about them in terms of life history and behaviour.
==Physical description==
Both species have slender bodies, small, pointed flippers and a small fluke. Conspicuously, neither species has a dorsal fin. The Northern right whale dolphin is the only dolphin in the Pacific with this property. Similarly, the Southern is the only finless dolphin in the southern hemisphere. The two species can be readily distinguished (apart from the geographical separation in their ranges) by the extent of the whiteness on the body. Both have white bellies; however, the area of white coloration on the Southern species covers much more of the body — including the flanks, flippers, beak and forehead.
Northern males are about long at sexual maturity. Females are . Both sexes become mature at about 10 years. New-born right whale dolphins are about half the length of their parents. The southern species is typically larger (up to ) and heavier (up to compared with the Northern's maximum of ). The dolphins live for about 40 years.
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「right whale dolphin」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|