Charlotte the stingray, possibly impregnated by shark, about to give birth at NC aquarium

HENDERSONVILLE, N.C. -- A North Carolina aquarium and shark lab are expecting a stingray to deliver a miracle any day now.

What's the miracle?

Charlotte the stingray, who is 12-14 years old, hasn't been around any male stingrays in her tank.

At first Brenda Ramer, the founder of Team Ecco, didn't believe it.

"People have written and said well they can hold male sperm for years and I'm like she's never been around a male, until we put those two little boys (sharks) in here," she said in an interview with ABC affiliate WLOS.

That's when she noticed the bite marks on Charlotte's body, a habit of mating sharks. That means one option for how Charlotte got pregnant is that she mated with Moe or Larry.

The other explanation, and the more likely scenario, Charlotte is going through a very rare process called parthenogenesis. That is when the eggs develop on their own without fertilization and create a clone of their mother.

"With our Bamboo Shark up in the other corner, we've had experience with Parthenogenesis with her 14 different times. We had one baby that lived 30 days outside of the egg," Ramer said.

She said her group has seen and studied several examples of parthenogenesis in sharks. However, it is a much more rare process in stingrays. The last full study, she says, took place a quarter of a century ago.

The aquarium where Charlotte lives in Hendersonville has been closed for renovations, but has since reopened.

"We're kind of expecting a deluge, which is great and that's fine. We want people to come and see her and talk to us about her," she said.

Ramer said when Charlotte does give birth, she could have as many as four pups.

If the pups are born alive, Ramer hopes to keep the family together, but will have to get a tank almost double the size of Charlotte's current home.

The birth will also provide a chance for Ramer's team to perform DNA testing on the pups to determine if they're a mixed breed or clones of their mother.

"It's a once in a bluest of blue moons experience. And it's like, 'wow.'"