Scientists solve the case of the ‘virgin stingray’ who became pregnant despite not sharing a tank with her own species

It’s the aquarium mystery that has gripped the world – just how did a ‘virgin stingray’ fall pregnant while living alone in a tank?

But after months of investigation – and a male shark falsely accused of sexual assault – it seems that mystery may finally have been solved. 

It’s been revealed that Charlotte the stingray at an aquarium in North Carolina has parthenogenesis – a rare type of asexual reproduction where offspring develop from unfertilised eggs.

Experts at the aquarium have now admitted it would have been ‘impossible’ for her to have mated with one 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. 

This is despite the claim that an inter-species hook-up could have occurred between Charlotte and a shark earlier this month.  

Questions will inevitably be asked of 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 mammals. 

Documented examples have included 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 is aware of for round stingrays, although other kinds of sharks, skates and rays have had these kinds of pregnancies in human care.

‘I’m not surprised, because nature finds a way of having this happen,’ she said.

‘We don’t know why it happens. Just that it’s kind of this really neat phenomenon that they seem to be able to do.

‘We should set the record straight that there aren’t some shark-ray shenanigans happening here.’

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

She lives in a tank at Aquarium and Shark Lab in Hendersonville, North Carolina that’s about 2,200 gallons, about the the size of a construction dumpster.

But staff are hoping to get a tank nearly twice that size to accommodate Charlotte’s offspring. 

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

She said lab staff first thought Charlotte had a tumour in September when they noticed a lump on her back that was ‘blowing up like a biscuit’ before an ultrasound revealed the pregnancy.

Ms Ramer said: ‘We were all like, ‘Shut the back door. There’s no way’.

‘We thought we were overfeeding her. But we were overfeeding her because she has more mouths to feed.

‘It is very rare to happen. But it’s happening in the middle of the Blue Ridge Mountains in rural North Carolina, hundreds of miles from the ocean.’

Round stingrays like Charlotte are abundant on the Pacific coasts of southern California and Mexico, often resting on the ocean’s sandy bottom near the shoreline.

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

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

Just like other species of stingray, the round stingray is aptly named for the venomous serrated spine located on the tail. 

Although stingrays do not attack people, the tail spines can cause painful wounds if stepped upon or handled without caution.