Scientists: Va. Shark's Pup a 'Virgin Birth'

"By the time they could realize what they were looking at, something munched the baby," he said of aquarium workers. The remains of the pup were used for the DNA testing.

Virgin birth has been proven in some bony fish, amphibians, reptiles and birds, and has been suspected among sharks in the wild. The scientists who studied the Virginia and Nebraska sharks said the newly formed pups acquired one set of chromosomes when the mother's chromosomes split during egg development, then united anew.

Absent the chromosomes present in the male sperm, the offspring of an asexual conception have reduced genetic diversity and, the scientists said, may be at a disadvantage for surviving in the wild. A pup, for instance, can be more susceptible to congenital disorders and diseases. The scientists said their findings offer "intriguing questions" about how frequently automictic parthenogenesis occurs in the wild.

"It is possible that parthenogenesis could become more common in these sharks if population densities become so low that females have trouble finding mates," said Mahmood Shivji, one of the scientists and director of the Guy Harvey Research Institute at Nova Southeastern University in Florida.

The DNA fingerprinting techniques used by the scientists are identical to those used in human paternity testing.

Chapman, who is with the Institute for Ocean Conservation Science at Stony Brook, was assisted in the study by Beth Firchau of the Virginia Aquarium.

Chapman and Shivji were on the team that made the first discovery of virgin birth involving the Nebraska shark.