Scubaism

Veterinarian Bob George sliced open Tidbit, the dead shark, and saw the outline of a fish. 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.

But sharks only breed with sharks of the same species, and there were no male blacktip reef sharks at the Virginia Aquarium & Marine Science Center in Virginia Beach. Could Tidbit have defied nature, resulting in the first known shark hybrid?

The other possibility was that Tidbit had conceived without needing a male at all. A recent study had documented the first confirmed case of asexual reproduction, or parthenogenesis, among sharks: a pup born at a Nebraska zoo came from an egg that developed in a female shark without sperm from a male.

One of the scientists who worked on that study contacted the aquarium, which sent him tissue samples from Tidbit and her pup for testing. If the pup’s DNA turns out to contain no contribution from a male shark, this would be the second known case of shark parthenogenesis.