Scientists solve case of 'virgin stingray' who got pregnant despite not sharing tank with her own species – and it was NOT 'shark scandal' as feared

It's the aquarium mystery that has gripped the world: How did a 'virgin stingray' become pregnant while living alone in an aquarium?

But after months of investigation – and a male shark falsely accused of sexual assault – it appears the mystery has finally been solved.

Charlotte the stingray at a North Carolina aquarium has been revealed to have parthenogenesis – a rare form of asexual reproduction in which offspring develop from unfertilized eggs.

Experts at the aquarium have now admitted it would have been 'impossible' for her to mate with any of the five small sharks that share her tank.

Now questions will inevitably be asked of the zoo, which has enjoyed wall-to-wall publicity since the story first broke.

One scientist said: 'We need to make it clear that there are no shark ray scandals happening here'

This is despite claims that an interspecies encounter between Charlotte and a shark could have taken place earlier this month.

Questions will inevitably be asked about the aquarium, which has enjoyed wall-to-wall publicity since the story first broke.

Parthenogenesis can occur in some insects, fish, amphibians, birds and reptiles, but not in mammals.

Documented examples include California condors, Komodo dragons, and yellow-bellied water snakes.

Kady Lyons, a research scientist at the Georgia Aquarium in Atlanta, said Charlotte's pregnancy is the only documented example she knows of of round stingrays, although other species of sharks, rays and rays have had these types of pregnancies under human care.

“I'm not surprised because nature finds a way to make this happen,” she said.

'We don't know why it's happening. Just that it's a really fun phenomenon that they seem to be capable of.

“We need to make it clear that there are no shark ray scandals happening here.”

Lab staff first thought Charlotte had a tumor when they noticed a lump on her back that was 'puffing up like a cookie' before an ultrasound revealed the pregnancy

The aquarium staff had been ultrasounding our ray, Charlotte, since September when she started swelling

Charlotte the stingray hasn't shared a water tank with a male of her species for at least eight years.

She lives in a tank at Aquarium and Shark Lab in Hendersonville, North Carolina, which is about 5,000 gallons, about the size of a construction dumpster.

But staff are hoping to get a tank almost twice as big to house Charlotte's offspring.

Brenda Ramer, executive director of the lab that encourages children to take an interest in science, said they can also install live cameras for an online livestream.

She said lab staff first thought Charlotte had a tumor in September when they noticed a lump on her back that “blowed up like a cookie” before an ultrasound revealed the pregnancy.

Ms Ramer said: 'We were all like, 'Close the back door. There is no way'.

'We thought we were feeding her too much. But we gave her too much food because she has more mouths to feed.

'It's very rare. But it's happening in the middle of the Blue Ridge Mountains in rural North Carolina, hundreds of miles from the ocean.”

Parthenogenesis is when eggs develop independently without fertilization and form a clone of the mother. Pictured: Aquarium and Shark Lab staff in Hendersonville, North Carolina

Round stingrays such as Charlotte are abundant on the Pacific coasts of Southern California and Mexico, often resting on the sandy bottom of the ocean near the coastline.

In the wild, they are usually the size of a small dinner plate and come in all shades of brown.

They eat small worms, crabs and mollusks, and are preyed upon by certain species of sharks, seals and giant sea bass.

Like other species of stingrays, the round stingray is aptly named for the venomous serrated spine on the tail.

Although stingrays do not attack humans, the tail spines can cause painful wounds if stepped on or handled without care.