Male Fish Borrows Egg to Clone Itself

A fish created by spontaneous androgenesis is the first known vertebrate to arise naturally by this asexual reproductive phenomenon.

Written byRuth Williams
| 3 min read

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Squalius alburnoidesISABEL CATALÃOResearchers in Portugal studying a rare type of hybrid fish in the Ocreza River have found an individual that is the exact genomic match to his father. While such androgenesis—the reproduction of a male with no female genetic component—occurs in some non-vertebrates and has been induced in vertebrates artificially, today’s report (May 24) in Royal Society Open Science is the first known description of a vertebrate reproducing this way in the wild.

“I was very surprised,” said Miguel Morgado-Santos, a graduate student at the University of Lisbon in Portugal who co-authored the study. “I thought maybe it was a mistake and we had captured the father.” But, when the researchers examined the animal’s mitochondrial DNA, which can only be inherited from the mother’s egg, they found that it differed from the father’s. “So, it was definitely an androgenetic individual,” he said.

“Although [androgenesis] is very rare, there are a number of species out there that do this and . . . it is interesting that people have found it now in a vertebrate,” said evolutionary biologist Laura Ross of the University of Edinburgh who was not involved in the study.

While the females of many species, including ...

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  • ruth williams

    Ruth is a freelance journalist. Before freelancing, Ruth was a news editor for the Journal of Cell Biology in New York and an assistant editor for Nature Reviews Neuroscience in London. Prior to that, she was a bona fide pipette-wielding, test tube–shaking, lab coat–shirking research scientist. She has a PhD in genetics from King’s College London, and was a postdoc in stem cell biology at Imperial College London. Today she lives and writes in Connecticut.

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