A bonnethead shark born in Nebraska’s Henry Doorly Zoo in 2001 has recently been proven to be a “virgin birth”. Known as parthenogenesis, this method of asexual reproduction enables females of a species to produce offspring without sperm from males of the species. The miraculous birth was confirmed when an analysis of the shark revealed no evidence of paternal DNA. Furthermore, the three probable mothers of the pup were sexually immature when captured, and none of them had encountered a male shark while living at the zoo. Asexual reproduction has been found in other animal families, but this is the first time it has been observed in sharks. It is thought that parthenogenesis occurred because the female sharks were unable to find suitable mates. Although asexual reproduction could be considered an adaptation for scenarios where it is difficult to find mates, it ultimately reduces genetic diversity. The long-term existence of certain shark species could be in jeopardy if they rely upon this method of creating offspring. Scientists hope that this new information will be incorporated into conservation plans in the future.
SOURCE: Biology Letters
