Researchers have documented the first case of virgin birth in cartilaginous fish, after busting the mystery surrounding the birth of a shark in an aquarium, that had only female sharks which had no contact with a male shark for three years.
The birth of the pup at Omaha's Henry Doorly Zoo, in the US, in December 2001 led to many conclusions including a possible insemination in one of the female sharks in the aquarium.
Female sharks have an organ that can store sperm, but a three-year storage would have been really extraordinary to believe.
The insemination theory still could be believed, but scientists could not imagine asexual reproduction among sharks.
"Because it was even more difficult to imagine asexual reproduction in a shark," New Scientist quoted Paulo Prodohl of Queen's University Belfast in Northern Ireland, as saying.
Researchers at Pew Institute for Ocean Science in the US led by Demian Chapman of the, used a DNA fingerprinting method akin to human paternity tests. The technique was determined to identify the mother.
When they deducted the mother's input from the pup's DNA to determine the father, to their surprise there was nothing left.
"In this particular case, after we subtracted the mother's DNA, there was nothing left. It was fantastic," says Prodohl.
The researchers then concluded that the pup had no father and had a virgin birth. This is the first recognized instance of an asexual reproduction in cartilaginous fish.
Later, the pup was killed by another fish in the aquarium.