Could a shark have impregnated a stingray at a North Carolina aquarium? What one expert says

A North Carolina stingray's pregnancy is stirring a debate.

How did it become pregnant without a male nearby, and did a shark have anything to do with it?

The Aquarium and Shark Lab by Team Ecco in Hendersonville, roughly 100 miles west of Charlotte, said its female stingray is expecting pups in the coming weeks, but there's one problem. The aquarium has no male stingrays.

Workers had placed sharks in the same tank, and a local media outlet reported the aquarium found bite marks on the ray. But can a female stingray become pregnant with a shark's baby? An outside expert says no.

Birth expected soon

The Hendersonville aquarium said it was afraid the female stingray, Charlotte, had cancer when she began to swell, but ultrasound results revealed the multiple growths within her body were actually eggs.

Charlotte is carrying as many as four pups, and Brenda Ramer, executive director of the aquarium, said Charlotte could give birth this month, the Associated Press reported.

A shark and stingray mix breed? Expert says don't get your hopes up

Kady Lyons, a research scientist at the Georgia Aquarium in Atlanta, told the AP that Charlotte’s pregnancy is the only phenoma she’s heard of for her species.

But when it comes to the stingray and its shark counterparts, can they make pups?

Lyons told the AP this theory is impossible. The two animals are different sizes, the animals wouldn’t match up anatomically. Neither would their DNA.

“We should set the record straight that there aren’t some shark-ray shenanigans happening here,” Lyons told the outlet.

Lyons, whose graduate work focused on the species, says other kinds of sharks, skates and rays have had these kinds of pregnancies happen in human care. Often, the trio of animals are grouped together in the same aquarium.

“I’m not surprised, because nature finds a way of having this happen,” Lyons said.

Round stingrays and white-spotted bamboo sharks

A round stingray like Charlotte can measure between 10 and 22 inches in width. Round stingrays reach sexual maturity at two and a half years old. Females can become pregnant with one to six pups, according to the California Department of Fish and Wildlife. Round stingrays are preyed on by northern elephant seals and larger fishes such as giant sea bass and sharks, especially leopard sharks.

White-spotted bamboo sharks, the species that reportedly shared the tank with Charlotte, primarily feeds on small marine fish and invertebrates, though species aren't well-documented, the Florida Museum of Natural History states. The sharks can be between 24 to 37 inches long.