Endangered Sawfish Have Virgin Births: First Discovered in the Wild

It turns out that endangered sawfish may be performing miracles: virgin births. Scientists have discovered that some female members of this species can reproduce without sex in the wild.

This isn't the first time that researchers have found examples of parthenogenesis, which is a virgin birth. However, these examples have primarily come from isolated examples of captive animals, including birds, reptiles and sharks. In those instances, the animals in question gave birth despite the fact that they'd had no opportunity to mate. Now, researchers have found that this also occurs in the wild.

In this case, the researchers conducted routine DNA fingerprinting of smalltooth sawfish in a Florida estuary. This DNA analysis revealed that about 3 percent of the sawfish are the products of virgin births.

Smalltooth sawfish are just one of five species of sawfish, a group of large rays that are known for their long, tooth-studied rostrum that they use to subdue small fish. These fish, though, are endangered and can only be found in a handful of locations in southern Florida.

"We were conducting routine DNA fingerprinting of the sawfish found in this area in order to see if relatives were often reproducing with relatives due to their small population size," said Andrew Fields, one of the researchers, in a news release. "What the DNA fingerprints told us was altogether more surprising: female sawfish are sometimes reproducing without even mating."

Vertebrate parthenogenesis, or virgin birth, is thought to occur when an unfertilized egg absorbs a genetically identical sister cell. The resulting offspring have about half of the genetic diversity of their mothers and often die. In this case, though, the seven parthenogens that the researchers discovered were perfectly healthy.

The findings are published in the journal Current Biology.

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