Stingray experts explain Charlotte’s ‘immaculate conception’ – and why the North Carolina aquarium doesn’t know when she will actually give birth

The immaculate conception of Charlotte the stingray, which has fascinated marine animal lovers around the world, now has a scientific explanation.

The stingray conceived her pups without a male partner, but experts said her pregnancy is not that unusual and attributed it to parthenogenesis – a scientific term for a virgin birth.

Parthenogenesis is common in sharks and stingrays and occurs when the mammal has been isolated for a long time and effectively produces a clone of itself.

Charlotte is on display at the Aquarium & Shark Lab in Hendersonville, North Carolina, where it was previously speculated that she was impregnated by a white-spotted bamboo shark that was believed to be in the tank with her.

But experts said this is not possible and parthenogenesis is the most likely explanation.

Stingray experts say Charlotte’s ‘miracle birth’ is most likely due to parthenogenesis – a scientific term for virgin birth

Another, more unlikely scenario for Charlotte's immaculate conception is that stingrays can carry sperm for up to a year.  But she has been in isolation too long for this to happen, experts say

Another, more unlikely scenario for Charlotte’s immaculate conception is that stingrays can carry sperm for up to a year. But she has been in isolation too long for this to happen, experts say

There is only one other possible explanation for Charlotte’s “miracle birth,” according to Dr. Christopher Lowe, professor of marine biology and director of the Shark Lab at California State University.

“They can get pregnant in two ways without seeing them mate with a male,” Lowe told Dailymail.com.

The first is that “many species of sharks and rays can store sperm for at least a year,” but said this is unlikely because Charlotte has been alone for too long.

“It turns out that parthenogenesis is more common in sharks and rays than we previously thought, so this is the most likely explanation,” Lowe said, adding that “a rapid DNA test will confirm whether the female is producing viable young.”

Kevin Feldheim, a researcher at Chicago’s Field Museum and an expert on parthenogenesis, told Dailymail.com that Charlotte’s case marks the first time parthenogenesis has been documented in her species, making it the 15th species documented overall.

The aquarium provides regular updates on Charlotte’s condition and says there is no sign of the pups yet, although an ultrasound showed she is carrying as many as four offspring.

Researchers say Charlotte's ultrasound shows she is carrying four puppies

Researchers say Charlotte’s ultrasound shows she is carrying four puppies

Certain animals can reproduce through 'facultative parthenogenesis', where the egg is fertilized with cells from the mother rather than by a male.

Certain animals can reproduce through ‘facultative parthenogenesis’, where the egg is fertilized with cells from the mother rather than by a male.

However, the team has so far been unable to provide a date for when Charlotte is expected to give birth, and Lowe said this is “probably because they don’t know exactly when she started developing an embryo, and we don’t know or parthenogenesis requires a longer gestation period.’

Round stingrays typically have a shorter gestation period compared to other species, with their pregnancy lasting three to four months depending on the temperature of the water.

He added that “the more and longer some species are kept in captivity, the more we learn about these kinds of oddities.”

It’s difficult to know the due date because it’s difficult to determine how far along in the pregnancy the stingray was when she became pregnant, Lowe said.

Ultrasounds are typically performed on long-term pregnancies, Lowe said, so they couldn’t tell the stingray was pregnant until about a month before it gave birth.

The Aquarium & Shark Lab announced Charlotte’s “miracle birth” in a Facebook post early last month, sparking worldwide interest in how the stingray itself could have become pregnant, even going so far as to suggest she had been impregnated by a shark.

The Aquarium & Shark Lab suggested Charlotte could have been impregnated by a shark, but experts said that's impossible

The Aquarium & Shark Lab suggested Charlotte could have been impregnated by a shark, but experts said that’s impossible

Feldheim said he suspected the aquarium “made that as a kind of offhand comment, but for whatever reason, the idea of ​​a ray-shark hybrid really took off.”

In a separate interview, Feldheim said NBC News that the theory that a shark impregnated the Charlotte may have thrust her story into the global spotlight, but it has no basis in reality.

‘The difference between sharks and stingrays is 350 million years. And for comparison, the difference between humans and platypuses is 180 million years,” he told the newspaper.

‘The shark scientists weren’t really happy with that press release. No one would even consider that as an option,” he added.

Kady Lyons, a researcher at the Georgia Aquarium in Atlanta, said AP News the theory is impossible because the animals’ substantially different sizes mean they are not anatomically matched, nor is their DNA.

A round stingray like Charlotte is between 25 and 60 centimeters wide, while the white-spotted bamboo shark – which was reportedly in the aquarium with Charlotte – is between 60 and 90 centimeters long.

“We need to make it clear that there are no shark ray scandals happening here,” Lyons told the newspaper.

“There is nothing unnatural about asexual reproduction,” Mercedes Burns, a biologist at the University of Maryland, Baltimore County, told NBC News.

‘Invertebrates or fish do amazing things during their lives to reproduce successfully.’