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

媒體英語會帶大家一起學習 BBC 撰稿人在報道世界大事時常用到的單詞和短語。

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

研究人員首次發現了一種生活在佛羅里達州河口的鋸鰩能夠單性繁殖后代。人們推測這是此類物種的一種生存機制。此發現被刊登在《當代生物學》雜志上。以下是 Jonathan Webb 的報道：

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.