A stingray in the United States is pregnant – despite not sharing a tank with a male of her species for at least eight years.
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.
Experts have said it would have been impossible for her to have mated with one of the five small sharks that share her tank.
The cause is parthenogenesis – a rare type of asexual reproduction in which offspring develop from unfertilised eggs which can occur in some insects, fish, amphibians, birds and reptiles, but not mammals.
A female’s egg fuses with another cell, triggers cell division and leads to the creation of an embryo.
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’
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 lives in a tank about 2,200 gallons.
Brenda Ramer, executive director of the lab which encourages children to take an interest in science, said they are hoping to get a tank nearly twice that size to accommodate her offspring and install live cameras.
She said 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.
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
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.’
