日本高清色视频在线视频在,国产香蕉97碰碰视频碰碰看,丰满少妇av无码区,精品无码专区在线,久久无码专区免费看,四虎欧美精品永久地址99,亚洲色无码一区二区三区

 
 
您現(xiàn)在的位置: Language Tips > BBC > Media English

Sawfish 'virgin births' astonish science 野生鋸鰩單性繁殖

媒體英語(yǔ)會(huì)帶大家一起學(xué)習(xí) BBC 撰稿人在報(bào)道世界大事時(shí)常用到的單詞和短語(yǔ)。

Sawfish 'virgin births' astonish science 野生鋸鰩單性繁殖

The sawfish, a cousin of the shark, is an endangered species

研究人員首次發(fā)現(xiàn)了一種生活在佛羅里達(dá)州河口的能夠單性繁殖后代。人們推測(cè)這是此類物種的一種生存機(jī)制。此發(fā)現(xiàn)被刊登在《當(dāng)代生物學(xué)》雜志上。以下是 Jonathan Webb 的報(bào)道:

Despite growing up to 12 feet in length with a vicious-looking snout, the smalltooth sawfish is critically endangered. Researchers from Stony Brook University in New York were doing a survey of the creatures to check on their genetic diversity.

They were surprised to find seven female fish that had no sign of a genetic father. They were all daughters of a virgin birth or parthenogenesis – this bizarre mechanism in which embryo grows from an unfertilised egg may be more common than scientists thought.

In captivity, sharks, reptiles and turkeys have all been known to surprise zookeepers and farmers with virgin births. But these fish are the first vertebrate virgin offspring ever found in the wild.

Glossary 詞匯表 (點(diǎn)擊單詞收聽發(fā)音)

<strong id="xdwva"><div id="xdwva"></div></strong>
<label id="xdwva"></label>

<thead id="xdwva"></thead>
    <label id="xdwva"></label>

  1. 日本高清色视频在线视频在,国产香蕉97碰碰视频碰碰看,丰满少妇av无码区,精品无码专区在线,久久无码专区免费看,四虎欧美精品永久地址99,亚洲色无码一区二区三区 久久九九久精品国产日韩经典 国产国语国拍精品 啊v在线观看高清无码 视频一区二区欧美 久久精品爱爱唉爱