A Female Anaconda Gave Birth to 18 Babies Without Any Contact With a Male Snake

Photo Credit: Wikimedia Commons

An anaconda at the New England Aquarium in Boston had a “virgin birth,” as if anacondas weren’t already badass enough.

Anna, a 10-foot-long female anaconda, gave birth to baby anacondas in May. The sight of the babies shocked her caretakers, mainly because there are no males in the exhibit.

Biologist Tori Babson tells WGBH that there were actually 18 babies total, each of them about two feet long.

“I was cleaning up my tanks, getting everybody fed for the end of the day,” she said.

Then she heard something strange.

“One of the event staff walked by the tank and noticed that there were a bunch of little babies in the exhibit.”

Photo Credit: Wikimedia Commons

Unlike most snakes, anacondas don’t lay eggs. Instead, they have live births.

“We were all quite surprised,” she said. “[We] definitely had no idea that we had a pregnant snake. Equally surprised because there were no males in the exhibit. All four of the adults that are in there are all confirmed females.”

So, how did Anna achieve this feat? It’s a phenomenon known as parthenogenesis, and it sometimes happens in snakes when they’re in captivity and kept apart from males. This is only the second known case in green anacondas.

Photo Credit: Wikimedia Commons

In this case, Anna used her own DNA to produce her babies, and they are each essentially a clone of her.

Unfortunately, babies born by parthenogenesis are often less viable. Only two of Anna’s 18 babies are still alive now; 15 of them were stillborn.