摘要
Dolphins,aquatic mammals,are small toothed whales in the family delphinidae,numbering more than 50 species.Most species are highly social,and they are mainly distributed in the world's oceans and rivers.海豚,水生哺乳动物,海豚科的一种小型齿鲸,数量超过50种。大多数海豚物种都是高度群居的,主要分布于世界各大洋及河流中。
