字神帝國英語天地

今日主題：This Shark Is the Vertebrate Methuselah / 長壽之星——格陵蘭鯊魚

洪欣老師推薦：托福聽力最好的課外教材：60-Second Science
康康精選托福會考的主題，堅持每天精聽一定會進步的哦!!

建議方法：
1. 先聽兩三遍 (不看文稿)
2. 再一句一句聽寫 (每句都要聽寫數遍，直到寫出85%以上的字)
3. 最後check文稿，看哪聽不出來，單字沒背過，還是發音不熟。
4. 堅持天天聽，就能每天進步哦。

MP3音檔 (按右鍵可下載聽)：喜歡的同學，幫忙推或按讚哦~~
http://online1.tingclass.net/voas…/2016/20160821sa_earth.mp3

只有音檔怎夠，聽不懂地方，不用怕，康康幫你準備好中英文稿了：

中英文稿：
By human standards, a few vertebrate species have incredible longevity. Some tortoises live for nearly 200 years. Bowhead whales can live even a decade or two longer. But now there's a new champion: the Greenland shark—which conservative estimates have swimming in the seas for almost three centuries.
按照人類的標準，有一些脊椎動物壽命非常的長。有些海龜可以活將近200年。弓頭鯨可以活一二十年。但是人們發現了一個新的長壽王——格陵蘭鯊魚——保守估計，它們已經在海裡生活了將近3個世紀。

Julius Nielsen is a marine biologist and PhD student at the University of Copenhagen. While on a research vessel in Greenland where such sharks were accidentally caught, Nielsen became curious about the creatures.
茱莉葉斯•尼爾森是一名海洋生物學家同時也是哥本哈根大學的博士生。在格陵蘭的一艘科學考察船上，人們無意之間逮捕了格陵蘭鯊魚，尼爾森對這個生物充滿的好奇之心。

“And perhaps the biggest of all the mysteries were how long do these sharks actually live. Because it has been expected that they can get very old, and that's based on some observations of very, very slow growth…so the longevity could be exceptional and extreme, but it has just never been possible to investigate.”
可能最大的謎團是格陵蘭鯊魚的壽命到底有多久。因為基於對格陵蘭鯊魚的觀察，它們生長的非常的緩慢，所以它們的長壽現像也是非常的罕見的，但是調查其長壽的秘訣也並不是不可能的。

That's because Greenland sharks don't have the same body structures used for gauging the age of most fish or even other sharks. So Neilsen and colleagues used a new technique based on the lens of the eye. The centers of the lenses can be analyzed by radiocarbon dating to determine about when the shark was born. They tested 28 female sharks.
因為格陵蘭鯊魚不具備大多數魚類甚至其他鯊魚可以測量年齡的身體結構。所以，尼爾森和同事們採用了一項以眼睛晶狀體為基礎的新技術。人們可以通過放射性碳分析鏡片的中心來決定鯊魚出生的時間。研究人員檢測了28頭雌性鯊魚。

“And what we found was that the biggest shark in our analysis, and also the oldest shark, was estimated—the most likely single year age was almost approximately 390 years.”
研究發現，分析的最大的鯊魚，同時也是最年長的鯊魚，據估計，其最接近的年齡是390歲了。

Nielsen stresses that the estimate contains a fair amount of uncertainty. Though the likeliest age is 390, the shark could be as young as a mere 272. “That still makes the Greenland shark the longest-living vertebrate known to science.” And at the upper limit, it's possible that the shark is more than 500 years old. The study is in the journal Science.
尼爾森強調該種預測包含很多的不確定性。儘管其最有可能是390歲，但看起來也就是272歲的樣子。這是格陵蘭鯊魚成為迄今為止科學發現的最為長壽的脊椎動物。若往年長估計，該鯊魚也可能已經500多歲了。該研究結果發表在《科學》雜誌上。

Also shocking: the researchers estimate that the sharks live at least a century before they reach sexual maturity. “And of course it is absolutely amazing and difficult for a human mind to understand that sexual reproduction begins so late in life.”
同樣，令人震驚的是：研究人員估計格陵蘭鯊魚至少要到100歲，才能達到性成熟。“當然按照人類的思考方式，很難理解性成熟以及繁殖交配如此晚。

In the paper Nielsen and his colleagues stress the importance of caution and conservation. “And the thing about Greenland sharks is just we don't know how many sharks are out there. But it's clear that if you reach sexual maturity above 100 years then you are potentially sensitive to any kind of high bycatch rate and any kind of future commercial exploitations.”
在文章中尼爾森和同事們強調了關心和保護格陵蘭鯊魚的重要性。“我們不知道還有多少格陵蘭鯊魚。但是如果在100歲以後才能達到性成熟，那麼其對高捕捉率和未來的商業開發價值都是非常敏感的。”

With a century to do it, humans could inadvertently wipe out the entire next generation of these sharks during their long, slow adolescence.
在未來的一個世紀，在格陵蘭鯊魚漫長而緩慢的青春期內，人類可能一不小心就會將格陵蘭鯊魚的下一代給毀滅了。