Chalk it up to 2016. For the first known time, a shark has reproduced asexually after having previously produced offspring through mating. A zebra shark in an Australian aquarium has been reported to have made the switch in April of last year.
The proud and apparently determined mother, Leonie, delivered three pups, Cleo, CC and Gemini, at the Reef HQ Aquarium in Townsville, Queensland. She had previously had a male partner from 2006 through 2012, birthing 20 pups, until aquarium staff had trouble keeping up with the number of young she was having. But she had apparently not let that separation cramp her maternal style with the arrival of new litter of pups. Christine Dudgeon, a biologist at the University of Queensland, came to investigate and published her findings this week.
“There were two possible explanations for Leonie’s eggs hatching,” said Dudgeon. “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. “The other was parthenogenesis [asexual reproduction]. This has been seen in a handful of sharks, but none that had mated previously.”