手机APP下载

您现在的位置: 首页 > 在线广播 > 科学美国人 > 科学美国人地球系列 > 正文

科学美国人60秒:水污染迫使鲸鱼改变进食策略

来源:可可英语 编辑:aimee   可可英语APP下载 |  可可官方微信:ikekenet
 下载MP3到电脑  批量下载MP3和LRC到手机
加载中..
SP&uFMmUMH58Yq3[(i|V

&T3^W0W=otS,M7q)

This is Scientific American — 60-Second Science. I'm Jason G. Goldman.
Baleen whales feed by opening their gigantic maws, lunging forward in the water and engulfing gallons of seawater in their mouths. They strain the seawater back through their baleen plates, trapping vast numbers of tiny critters—fish, krill and others—that then get swallowed all at once. The species that share this method include what are called the rorqual whales, which include fin whales, sei whales, blue whales and humpback whales.
But now a team of Japanese and Thai researchers has discovered a never-before-seen type of feeding behavior in a rorqual called a Bryde's whale. These whales don't bother with the lunge. They simply open their mouths at the surface and let the seawater flow in, before straining and expelling the seawater through their baleen as usual.
The researchers call it tread-water feeding because of the way the whales gently undulate their tails to keep their heads near the surface of the water. They say it's the first passive feeding strategy ever seen in a baleen whale. The team, led by Takashi Iwata from the University of Tokyo, observed 31 different whales feed this way in the Gulf of Thailand.

=4*cO+[5ZmOaRy3

布氏鲸.jpg
Tread-water feeding is more energy-efficient than lunge-feeding, since the whales just have to bob their heads near the surface. But Iwata thinks that the odd behavior may have a darker origin.
The upper Gulf of Thailand is hypoxic—there's a serious lack of oxygen dissolved in the water, thanks mostly to sewage that flows into the sea from nearby rivers. The low oxygen levels might force the whales' prey towards the surface, where oxygen is a bit more plentiful. And if all the food is in one spot, then tread-water feeding might be the only way to get enough nutrition. Which means that these whales apparently improvised an improved strategy for survival in their polluted habitat.
Iwata wrote in an e-mail that his team witnessed tread-water feeding most often in adult-calf pairs. That observation leads him to suspect that the behavior might be socially learned, passed from parents to their offspring via imitation.
If that's true, then tread-water feeding could represent a form of culture, unique to the Bryde's whales that live in the Gulf of Thailand.
Thanks for listening for Scientific American — 60-Second Science. I'm Jason G. Goldman.

o7uWqiShSRr

P2fpLUR3aTCp-VXGA_gP=gpK1K9~[bax)@*klNT#3d#Y

重点单词   查看全部解释    
offspring ['ɔ:fspriŋ]

想一想再看

n. 子孙,后代,产物

 
species ['spi:ʃiz]

想一想再看

n. (单复同)物种,种类

 
unique [ju:'ni:k]

想一想再看

adj. 独一无二的,独特的,稀罕的

联想记忆
imitation [.imi'teiʃən]

想一想再看

n. 模仿,效法
adj. 假造的,冒充的

 
fin [fin]

想一想再看

n. 鳍,鱼翅,鳍状物,散热片,五元纸币 vt. 装上鳍

 
distrust [dis'trʌst]

想一想再看

n. 不信任 vt. 不信任

 
stress [stres]

想一想再看

n. 紧张,压力
v. 强调,着重

 
whale [weil]

想一想再看

n. 鲸
vi. 捕鲸
v. 鞭打,

 
survival [sə'vaivəl]

想一想再看

n. 生存,幸存者

联想记忆
drought [draut]

想一想再看

n. 干旱

联想记忆

发布评论我来说2句

    最新文章

    可可英语官方微信(微信号:ikekenet)

    每天向大家推送短小精悍的英语学习资料.

    添加方式1.扫描上方可可官方微信二维码。
    添加方式2.搜索微信号ikekenet添加即可。