The zebra shark is among the many species living in Shedd Aquarium enclosures.
An endangered zebra shark hatched some pups through "virgin birth" at Chicago's Shedd Aquarium. The event, which took place last month, has been mentioned in a study published in the Journal of Fish Biology. In a press release, the aquarium said that asexual reproduction is common for animals like starfish, deep-sea worms, and stick insects, but among vertebrates, it's a rarity. Shedd called the process as parthenogenesis, a type of reproduction in which female animals fertilize eggs with their own genetic material.
"We've known for several years that parthenogenesis occurs in animals like sharks, but some aspects of it remain unknown, like why it occurs and what triggers it," Kevin Feldhim, a researcher at Chicago's Field Museum and one of the authors of the study, said in the release. "This latest paper is just another step in learning why these 'virgin births' happen."
The aquarium started to see success in breeding in 2004. "We also began genetic testing to confirm which of the sharks were the parents of the offspring," said Lise Watson, assistant director of animal operations and habitats at Shedd Aquarium and another author of the study.
"By confirming the lineage of the offspring, we could more soundly make decisions on future breeding efforts to maintain maximum genetic diversity," she further said.
The Shedd Aquarium has a massive habitat for a variety of sharks where they roam around freely. But the zebra shark, named Bubbles according to ABC Chicago, did not choose any of the male sharks as mate who usually surrounded her, leaving scientists amused.
An analysis of the DNA of Bubbles' shark pups showed they didn't match any of the male sharks in the enclosure.
This is only the second documented case of a virgin birth in sharks.