Veterinarian Bob George sliced open the dead shark and saw the outline of a fish.No surprise there, since sharks digest their food slowly.
Then George realized he wasn't looking at the stomach of the blacktip reef shark, but at her uterus. In it was a perfectly formed, 10-inch-long shark pup that was almost ready to be born.
George was dumbfounded.
He had been examining the shark, Tidbit, to figure out why she reacted badly to routine sedatives during a physical and died, hours after biting an aquarium curator on the shin. Now there was a bigger mystery: How did Tidbit get pregnant?
Asexual reproduction among sharks is more likely to happen in captivity, when there is no other option for reproduction, than in the wild, Hueter said.
Crossbreeding, on the other hand, is not known to happen at all among sharks, said Heather Thomas, aquarist at the John G. Shedd Aquarium in Chicago.
``It's not natural,'' Thomas said. ``If you've got a shark that needs to swim to breathe and cross it with a shark that can lay on the bottom to breathe, what are you going to get? Are you going to get these weird mutations?''
If the pup indeed turns out to be a hybrid, DNA testing should be able to identify the species of the father. The most likely candidate would be a sandbar shark, the most similar shark to a blacktip reef in the aquarium, George said.
Source: Guardian & Yahoo News
Tags: Shark | Asexual Reproduction
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