A bonnethead shark born in 2001 in a Nebraska zoo was the result of a so-called virgin birth, DNA evidence shows. It is the first confirmed case of a female shark fertilizing her own eggs and giving birth without sperm from a male, a process known as parthenogenesis.

Parthenogenesis has been seen in about 70 species, mainly in insects but also in several lizards, for example. Until now it was thought that all shark species used internal fertilization through copulation to produce their young.