Scientists at an aquarium in North Carolina were left puzzled when a stingray developed eggs, despite there being no male in her tank. The Aquarium and Shark Lab by Team Ecco in Hendersonville reported the discovery, leading to concerns that the stingray may have cancer. After an ultrasound, the lab’s executive director concluded that the growths were indeed eggs.
One possible explanation for the pregnancy is parthenogenesis, a process in which a female can produce an embryo asexually without an egg being fertilized with sperm. This survival mechanism is used to preserve the species and usually occurs when no males are present, such as in an aquarium or a secluded area of the deep sea.
However, scientists have developed another theory after noticing bite marks on the stingray. The stingray shared her tank with two male sharks, and one theory suggests that a male shark may have mated with her, resulting in her pregnancy with two to three pups. Genetic tests will need to be conducted after the birth to confirm this theory.
Sharks and stingrays are closely related taxonomically, making interbreeding between them theoretically possible. The staff at the aquarium is expecting the stingray to give birth at any moment and plans to provide updates on their website and Facebook page.