Sawfish 'virgin births' astonish science 野生锯鳐单性繁殖

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

研究人员首次发现了一种生活在佛罗里达州河口的能够单性繁殖后代。人们推测这是此类物种的一种生存机制。此发现被刊登在《当代生物学》杂志上。以下是 Jonathan Webb 的报道:

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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.