How did an aquarium stingray get pregnant without companion?

How did an aquarium stingray get pregnant without companion?

By Stephanie Pappas Published by Jeanna Bryner

A stingray in a small aquarium in Hendersonville, in North Carolina, has become pregnant – despite a reservoir without male radius.

This apparently miraculous event aroused online speculation according to which the Stingray waiting, Charlotte, may have been permeated by one of the small sharks that share his tank at the Aquarium & Shark Lab. But the experts say that it is extraordinarily improbable, equally suggesting that a lion and a wolf could have babies “li-lolves” (“wolvions”?).

In fact, the shark rays babies would be even more dramatic than that, explains Demian Chapman, director of the shark and rays of the Mote Marine Laboratory & Aquarium in Florida. The last common ancestor of cats and dogs lived around 45 million years ago. Sharks and rays diverse from each other at least 300 million years ago, according to a 2021 Document in the newspaper Development biology.

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There is another explanation for Charlotte's imminent maternity hospital, and it is not much less bizarre: it has almost imbued itself, a phenomenon known as parthenogenesis.

“A wide variety of shark and ray species are known to reproduce like that in captivity,” explains Chapman, who studied the first known case of Parthenogenesis in a hammer sharkwhich occurred in 2001. “We even have evidence of a kind of radius doing so in nature.”

Charlotte, a stingray round (Urobatis Halleri), has a notable baby bump (visible on its underside and back) and can give birth at any time, according to the Aquarium & Shark Lab, which is managed by the team of the ECCO non -profit educational organization. Pregnancy was confirmed by ultrasound. Charlotte would be the first known round known to having undergone a partheogenesis, explains Kady Lyons, researcher at the Georgia Aquarium. “It's a bit cool that we have another documented case of this in a new species,” explains Lyons.

Researchers do not fully understand why parthenogenesis occurs or what triggers it. Here is how the process works: inside the body of the female, cell division creates sex cells or gametes. This division, called meiosis, leads to the egg, which can possibly be fertilized by sperm and three additional cells called polar body. The egg and each polar body each contain half of the complement of the genes necessary to make a new organism. In the Parthenogenesis, a polar body merges with the non -fertilized egg, triggering it to form an embryo.

This is different from cloning, warns Lyon, which would create an exact copy of the Ray Mother. In the parthenogenesis, because the egg and the polar body contain only parts of the mother's genome, babies find themselves less genetically diverse than their mother. Certain parthenogenetic species bypass this by doubling their genes before dividing their sex cells: the Whiptail lizards of the genus Aspidoscelis Reduce yourself just by reproducing this way. But for many other species which only from time in time undergo partheogenesis, offspring might not be so robust, says Lyons. “You can consider them as a very consanguineous person,” she adds.

Even the typical round round reproduction is eccentric. The female stinging lines mate with several men in the spring and three to four months later, give birth to races with several different fathers, known as Lyons. And they bathe their fetus in a kind of nutritious uterine liquid, much like mammal milk, which gives them a boost when they emerge. At birth, babies have less than three inches in diameter – on the diameter of a baseball – and are ready to fend for themselves.

“They are super adorable,” says Lyons.