Sea cow is also called manatee.Manatees are aquatic1 mammals2 that belongto a group of animals called Sirenia3. In thisgroup there are also dugongs. Dugongs andmanatees are similar in size， colour andshape， but they’re different in their tails4.t u b ， l i a t d e d n u o r ， g i b a e v a h s e e t a n a Mdugongs have flat tails， like whales’tails.

海牛也叫manatee，是一種水生哺乳動物，屬海牛目。海牛目的動物也包括儒艮。儒艮和海牛在大小、顏色和形狀上都很相似，但它們的尾巴略有不同。海牛的尾巴大而圓，而儒艮則有著扁平的尾巴，就像鯨魚尾巴一樣。

Manateescanlivetotheageofabout50 or60 in thewild， butitispossibletheycouldlivelonger.Babymanateesstaywiththeirmotherforabouttwoyearsaftertheyareborn.

海牛在野外可以活到50 到60 歲左右，但也有可能活得更久。海牛寶寶出生后的前兩年會和媽媽待在一起。

Unlike most mammals， manatees only have six bones in their neck. Usuallymammals have seven， like humans5. With this short neck， manatees could move itshead up and down， but not side to side. To look left and right， a manatee must turn itswhole body. Manatees are huge animals， much bigger than humans. A manatee growsinto 2.5 to 3.5 meters long and around 350 to 500 kilograms weight on average6.

與大多數(shù)哺乳動物不同，海牛的脖子只有六塊骨頭。通常，哺乳動物都有七塊，比如人類。由于脖子很短，海牛只可以上下擺動頭部，但不能左右移動。要左右看，海牛必須轉(zhuǎn)動整個身體。海牛是一種巨大的動物，比人類大得多。成年海牛大約有2.5 到3.5 米長，平均體重約 350 到500 公斤。

What do manatees eat？

海牛吃什么？

Seagrasses and other plants underwater are most of a manatee’s food. Manateesspend about eight hours each day finding and digging plants. They eat up to 15% oftheir weight in food each day.

海草和其他水下植物是海牛的主要食物來源。它們每天花大約 8 個小時尋找和挖掘可以吃的植物，每天吃的食物重量高達(dá)體重的15%。

How long can manatees stay underwater？

海牛能在水下待多久？

Manatees are fully aquatic， whichmeans they don’t live on the land. But asmammals， they need air to breathe7.When awake， they usually come up to thesurface8 every two to four minutes， butthey can hold their breath for much longer.The longest record was 24 minutes by a West Indian manatee in Florida.

海牛是完全的水棲動物，這意味著它們不生活在陸地上。但作為哺乳動物，它們需要呼吸空氣。醒著的時候，它們通常每隔兩到四分鐘就會浮出水面一次，但它們在水下屏住呼吸的時間可以更長。佛羅里達(dá)州的一只西印度海牛創(chuàng)下了24 分鐘的最長紀(jì)錄。

Adult manatees sleep underwater from 10 to 12 hours a day， but they come upfor air every 15 to 20 minutes. When a manatee sleeps， they need less air.

成年海牛每天在水下睡10 到 12 小時的覺，但每15 到20 分鐘就會上來呼吸一次空氣。海牛睡覺時，需要的空氣更少。

How fast can a manatee swim？

海牛能游多快？

Manatees have a much slowerspeed than other mammals of theirsize. They are slow swimmers， butcan have a top speed of about 25kilometers per hour. However， theycan’t always swim in this speed.

海牛的速度比其他同等體型的哺乳動物慢得多。它們的游泳速度較慢，最高時速大約25 公里。然而，它們并不能一直以這種速度游動。

Are manatees in danger？

海牛是否瀕臨滅絕？

All manatees are in great danger or at a high risk9 of dying out. About140，000 manatees living in Amazon area were killed between 1935 and 1954 fortheir meat， fat and skin. People eat their meat， make their fat into oil， and use theirskin to make leather10. The manatee in Africa are also in danger， but people aretrying to save them. Manatee hunting is now illegal11 in some African countries.

所有海牛都處于極度危險或瀕臨滅絕的境地。1935 年至 1954 年間，生活在亞馬遜地區(qū)的約14 萬頭海牛因其肉、脂肪和皮而被捕殺。人們吃海牛肉，用脂肪煉油，用海牛皮做皮革。非洲的海牛也瀕臨滅絕，但人們正在采取措施保護(hù)它們。在一些非洲國家，獵殺海牛現(xiàn)在是非法的。

Notes

1. aquatic 水生的；水棲

2. mammal 哺乳動物

3. sirenia 海牛目

4. tail 尾巴

5. human 人類

6. on average 平均來看

7. breathe 呼吸breath 呼吸；氣息

8. surface 表面；水面

9. risk 危險；風(fēng)險

10. leather 皮革

11. illegal 非法的