**Related Video Above: Find out more on the Greater Cleveland Aquarium

HENDERSONVILLE, N.C. (WJW) — A female stingray at a North Carolina aquarium is pregnant, something handlers were shocked to discover as there are no male stingrays in the tank.

The mystery was announced on the Aquarium and Shark Lab by Team ECCO’s social media pages earlier this week, where the crew also showed live video of the stingray (sporting a hump on her back) getting an ultrasound.

“Yes, our stingray Charlotte is about to be a mom!” the aquarium said on Instagram. “Pups are either the result of parthenogenesis or cross mating with a small shark.”

Parthenogenesis is the ability to asexually reproduce, and according to Dr. April Smith on her North Carolina Science Trail blog, that isn’t entirely unheard of among stingrays.

“Parthenogenesis offspring are, typically, all female, and this occurs in a situation where there are no males present (i.e., zoo/aquarium usually, or perhaps a secluded natural environment like the deep sea),” she wrote. “It’s a survival mechanism that allows for the preservation of a species.”

On the other hand, white-spot bamboo male sharks were reportedly introduced to the stingray’s tank last summer.

Once the new stingrays are born, the aquarium plans to do DNA testing to clear up the confusion.

As of Saturday, the baby stingrays have not yet made an entrance. The aquarium said it plans to keep the public updated on its social media pages.