Oct 12, 2008

Second case of "Virgin Birth" in Shark

A female Atlantic blacktip shark in the Virginia Aquarium & Marine Science Center fertilized her own egg without mating with a male shark. In a study report published in the latest issue of the Journal of Fish Biology, scientists have confirmed that it was the second case of a "virgin birth" in a shark.

The female shark, dubbed Tidbit, was caught in the wild when she was very young and lived in the aquarium for eight years without any contact with male shark. She died due to stress-related complications related to her pregnancy, during a routine physical exam in May 2007. Necropsy after her death revealed that she was carrying a 12 inches long pup foetus. DNA tests of the pup confirmed that it was a case of "virgin birth", that means the embryo came from the mother.

The first "virgin birth", which means asexual reproduction or parthenogenesis, in shark was ducumented at an Omaha zoo in 2001. The baby bonnethead shark born at the Henry Doorly Zoo in Omaha, Nebraska was killed within hours of its birth by a stingray in the same tank.

So, this second case of "virgin birth" confirmed that like some other vertebrates, birds, snakes and reptiles, parthenogenesis occurs among shark species. Link


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