Manatees are born underwater and never leave it-though they must surface to breathe every few minutes .
海牛是在水下出生的，尽管它们需要隔几分钟探出水面做个呼吸，但是它们一辈子不会离开那里。
Many are large animals , such as rhinos , tapirs , elephants , dugongs and manatees .
它们中的许多都是大型哺乳动物，比如犀牛、貘、大象、儒艮和海牛。
Sailors of old sometimes mistook manatees for mermaids , which shows how months at sea quaffing rum and missing female company can cloud one 's vision .
For instance , how terrestrial mammals moved back into the water and evolved into whales , seals and manatees continues to puzzle fish and colleagues .
