Friday, October 10, 2008

Virgin birth - Its a shark this time.

RICHMOND, Virginia (AP) -- Scientists have confirmed the second case of a "virgin birth" in a shark. A blacktip shark in the wild patrols the vast expanse of the Indian Ocean. In a study reported Friday in the Journal of Fish Biology, scientists said DNA testing proved that a pup carried by a female blacktip shark in a Virginia aquarium contained no genetic material from a male.

The first documented case of asexual reproduction, or parthenogenesis, among sharks involved a pup born to a hammerhead at an Omaha, Nebraska, zoo. "This first case was no fluke," Demian Chapman, a shark scientist and lead author of the second study, said in a statement. "It is quite possible that this is something female sharks of many species can do on occasion."

The scientists cautioned that the rare asexual births should not be viewed as a possible solution to declining global shark populations. The aquarium sharks that reproduced without mates each carried only one pup, while some species can produce litters of a dozen or more.
"It is very unlikely that a small number of female survivors could build their numbers up very quickly by undergoing virgin birth," Chapman said.     read more ....

Related news

1. National Geographic -
2. BBC -
3. CNN -
4. Sunday Morning Herald, Australia -
5. New Scientist -
6. Nova -

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