Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

A Genetic Investigation Into a Shark 'Virgin-Birth': Asexual Reproduction, Inter-Specific Hybridization or Long-Term Sperm Retention?

Event Name/Location

American Elasmobranch Society 20th Annual Meeting, Norman, OK, June, 2004

Presentation Date


Document Type

Conference Proceeding




Asexual reproduction via parthenogenesis is relatively rare among chordates and has never been recorded in the class Chondrichthyes. In December 2001, a female Bonnethead Shark, Sphyrna tiburo, gave birth in captivity to a single female pup, despite having been separated from any male S. tiburo for a period of at least three years. Widespread media attention quickly led to this case being billed as "the shark-virgin birth" (i.e., asexual reproduction), however other explanations (sexual reproduction coupled with long-term sperm storage, inter-specific hybridization with a male leopard shark, Triakis semifasciata, tank-mate) could not be ruled out. We present the results of a genetic investigation aimed at ruling out these alternatives and determining whether this birth is the first known case of asexual reproduction in this ancient lineage.