It’s the aquarium mystery that has gripped the world – just how did a ‘virgin stingray’ fall pregnant while living alone in a tank?
Now, after months of investigation – and a male shark falsely accused of sexual assault – it seems that the mystery may finally have been solved.
Experts at the aquarium in North Carolina have now admitted it would have been ‘impossible’ for Charlotte the stingray to have mated with one of the five small sharks that share her tank.
Instead, they say that Charlotte went through parthenogenesis – a rare type of asexual reproduction where offspring develop from unfertilised eggs.
The curious case has garnered the interest of viewers worldwide, with one joking on Instagram: ‘This Maury episode is gonna be crazy.’
Charlotte, who has spent much of her life at the Aquarium and Shark Lab in Hendersonville, North Carolina is expected to give birth to up to four pups in the next fortnight
A scientist said: ‘We should set the record straight that there aren’t some shark-ray shenanigans happening here’
‘Virgin birth’ is a natural process called facultative parthenogenesis, meaning a female is able to produce young without any involvement from a male.
It’s extremely rare in nature, although it is found in some other species, most notably mayflies, turkeys, pythons, and boa constrictors.
Animals in the wild generally do not reproduce in this way, however, some research suggests that endangered animals might do so more frequently as finding a mate becomes harder.
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.
However, 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 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.
Lab staff first thought Charlotte had a tumour when they noticed a lump on her back that was ‘blowing up like a biscuit’ before an ultrasound revealed the pregnancy
Aquarium staff had been doing ultrasound on our ray, Charlotte, since September, when she began to swell
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Two male chicks born in California hatched from unfertilized eggs
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.
Parthenogenesis is when eggs develop on their own without fertilization and create a clone of the mother. Pictured, staff at Aquarium and Shark Lab in Hendersonville, North Carolina
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.