‘Pregnant Virgin’ Stingray Won’t Give Birth After All—Here’s Why

In February, the Aquarium & Shark Lab by Team ECCO in Hendersonville, North Carolina, announced that Charlotte, a female round stingray at the facility, was due to give birth to four pups. This news came as a shock—Charlotte had not shared a tank with a male ray for at least eight years.

The revelation prompted speculation across the internet. But what really drew attention was an out-there proposal: That Charlotte, who had shark bites, a sign of mating for the species, had been impregnated by one of the white-spotted bamboo sharks sharing her tank. Alternatively, she could have reproduced asexually, which would have been a first for her species.

Biologists promptly dismissed the cross-mating theory as impossible. So, experts presumed Charlotte’s pregnancy was a result of parthenogenesis, a form of asexual reproduction in which an egg develops into an embryo without male fertilization.

But as months passed with no news of a birth from the aquarium, Charlotte, allegedly pregnant since November, came to be long past her February due date. Some began to suspect the aquarium was withholding information.

Last week, Team ECCO shared a long-awaited update.

“We regret the delay of updates regarding Charlotte. This time was necessary to gather data and analyze lab and testing results,” the aquarium wrote on Facebook. Then, the team revealed the stingray has a “rare reproductive disease.”

In another post shared Wednesday, the aquarium confirmed Charlotte is “no longer pregnant due to her reproductive disease.”

Charlotte is “stable” and hasn’t shown any drop in appetite or activity, per the post. As medical experts review her test results and develop a care plan, the aquarium is temporarily closed.

“We saw eggs on the ultrasound,” Brenda Ramer, the owner of the aquarium, tells WLOS News 13’s Kimberly King. “We saw movement on the ultrasound. And then, the veterinarians we consulted through the whole thing, as this progressed, we saw cysts—or what might appear to be cysts. That’s when we brought in and started doing blood work and fluid work to see what else is going on. … All they know right now is it’s a disease that affects the reproductive system.”

In an article published days before the aquarium’s update, Larry Boles, director of the aquarium science program at Oregon Coast Community College, told the Assembly’s Emily Cataneo that he wondered if Charlotte had a reproductive disease from the onset.

“Really from the beginning, all I said, and all my colleagues said, was that this animal needs to see a veterinarian,” Boles told the Assembly. While the aquarium may have been working with vets, he added, the facility is not accredited by the Association of Zoos & Aquariums, which means it does not have to abide by certain standards such as having regular veterinary inspections.

Many older female stingrays living in managed conservation environments experience reproductive disease, per the Morris Animal Foundation. This condition is denoted by cysts on the ovaries, failure to release eggs during ovulation cycles and an enlarged uterus.

“Depending on the [type of] reproductive disease, it could be fatal,” Benjamin Perlman, an ichthyologist at California State University, Long Beach, tells National Geographic’s Liz Langley.

The aquarium was unable to detail the illness beyond labeling it as reproductive disease due to limited research on the condition, per the Facebook post.

“The most unusual thing for me is that I recall seeing footage of an ultrasound [which Charlotte had in February], and on that ultrasound you could see an embryonic ray,” says Warren Booth, who studies parthenogenesis at Virginia Tech, to NPR’s Bill Chappell. He wonders “if the female aborted the developing embryo(s) and either consumed them or a tank mate consumed them.”

Alternatively, “having cystic ovaries could possibly confuse someone to think a ray was pregnant,” Perlman tells National Geographic.

But Ramer tells WLOS News 13 that the ray’s pregnancy was legitimate, and February’s announcement was not a hoax.

“The eggs were confirmed, and that’s what I can tell you,” Ramer says to the publication. “This other thing has stepped in now, and I can’t control biological processes.”

Aaron Boorstein | READ MORE

Aaron Boorstein was an intern with Smithsonian magazine.