In townsville, Australia, a zebra shark Leonie had done some thing that now baffles biologists. In the aquarium, a female zebra shark has abnormally asexually reproduced. There have been accounts of other vertebrates that have “Virgin Births”. Other creatures have these abnormalities as a means of survival.

The more abnormal thing was that this female shark had mated with a male shark before. In 2006, the female shark had reproduced asexually. While the female shark had been separated from the male sharks with her daughter for three years. Another 3 years, the daughter was separated from the males to produce the same results as her mother and reproduce without a partner.

Christine dudgeon had work for the aquarium and is the caretaker for these sharks had wrote in a report that this behavior wasn’t unusual. Dudgeon pointed out that sharks simply laying eggs without a male present is not unusual. “It’s much like a chicken — they lay eggs whether they are fertilized or not, if the conditions are good,” she told CNN.

Although some see this as unusual, some theories had emerged from Dudgeon. There were two possible explanations for Leonie’s eggs hatching, one was sperm storage, which has been documented in several occasions. Sharks have been known to store sperm from male sharks for extended periods of time. While the other was parthenogenesis [asexual reproduction]. This has been seen in a handful of sharks, but none that had mated previously.” Dudgeon says

Some Biologists saw that most of the eggs had identical DNA to the mother, slightly proving the eggs weren’t produced through sperm storage. “It was definitely a surprise,” said Hamish Tristram, a senior aquarist with Reef HQ. “She had been mating successfully for several years, and there was nothing much published about such large animals switching reproductive strategy so quickly.”

Dudgeon and her team are now waiting for Leonie’s offspring to reach sexual maturity before taking the next step in their research. “We are keeping an eye on them, and ultimately we want to find out if her offspring can reproduce sexually,” she said, as such an occurrence would be unusual.

The caretakers find it quite unusual that it took this quick for the sharks to adapt and reproduce asexually. The zebra sharks are also endangered and also called leopard sharks. Some scientists are theorizing that the sharks have learned to breed asexually because of a dormant breeding season. “Maybe in the short term the female (sharks) can do without males, but in the long term we need males again eventually,” Dudgeon said. “We still need to keep them within arm’s reach.”