Nuestra Tiberone de la Conception, Hammerhead shark, Sphyrna zygaena

A female hammerhead shark gave birth to a pup in the Henry Doorly Zoo in Nebraska in 2001 despite having no contact with a male shark. Thanks to new DNA profiling technology, scientists have been able to show conclusively that the shark pup contained no genetic material from a male. Before you whip out your Book of Revelations and start begging for forgiveness, you should know that this is an example of a naturally occurring phenomenon called parthenogenesis. In parthenogenesis, egg cells develop as an embryo without the addition of any genetic material from a male sperm cell. This reproductive process has been witnessed in bony fish before, but never in cartilaginous fish like sharks.

Asexual reproduction decreases genetic diversity, and thus can weaken a species as a whole. Witnessing the hammerhead’s virgin birth is thus a cause of concern for scientists, worried about further weakening of already threatened shark species in the world.


  1. #1 mei
    August 5, 2009

    Sorry if this is off topic but I’m thinking of buying this book. Curious if anyone’s has checked out the new book “Hell’s Aquarium” by Steve Alten? I know he’s been a best selling author before, but wanted to see if anyone had read this book first? It’s about the ancient prehistoric shark Megalodon, which makes the current Great White Shark look like a gold fish. Check out the trailer below, pretty awesome:


  2. #2 saç ekimi
    December 24, 2010

    I cant believe this is a fish !!!

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