Scientists have proved that the endangered sawfish can and has reproduced in the wild without mating. It’s believed that the miracle ‘virgin births’ are a response to dwindling stocks of the species, with females unable to find a mate.
The findings were made in study by ecologists off the coast of Florida, published in the journal Current Biology.
Although it seems impossible, a number of animals held in captivity have exhibited ‘virgin births’ of this kind, including sharks, snakes, and turkeys. Some types of whiptail lizard are, bizarrely, all female!
But the sawfish, which grows up to four metres long and was featured in one of Jeremy Wade’s Classic River Monsters episodes, is the first sexually reproductive species found to have exhibited this behaviour in the wild.
The survey studied 190 sawfish and of these, the DNA of seven of them indicated that they had only one parent. The ecologists concluded that they can only have been produced by what’s called parthenogenesis, a process by which an unfertilized egg absorbs another and develops into an embryo.
It is not known if these seven fish can be sexually reproductive themselves.
All species of sawfishes are listed as Endangered or Critically Endangered by the IUCN, and face the threat of extinction as a result of habitat loss and overfishing.
Wikipedia reports that global populations of every species of sawfishes are estimated to have fallen to less than 10% of their historic levels, and they have been lost from at least 80% of their historic range.