Scientists have confirmed the second case of a "virgin birth" in a shark. In a study reported Friday in the Journal of Fish Biology, scientists said DNA testing proved that a pup carried by a female Atlantic blacktip shark in the Virginia Aquarium & Marine Science Center contained no genetic material from a male.Odd, nature is.
The first documented case of asexual reproduction, or parthenogenesis, among sharks involved a pup born to a hammerhead at an Omaha, Neb. zoo.
The aquarium sharks that reproduced without mates each carried only one pup, while some shark species can produce litters numbering in the dozen or more.
In May 2007, the 5-foot, 94-pound shark died of stress-related complications related to her unknown pregnancy after undergoing a yearly checkup. The 10-inch shark pup was found during a necropsy of Tidbit, surprising aquarium officials. No male blacktip sharks were present during her eight years at the aquarium.
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.
The DNA fingerprinting techniques used by the scientists are identical to those used in human paternity testing.
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