We have a “news of the weird” story for you! Zoo staff made an incredible discovery in the HerpAquarium — a world’s first! We are proud to announce that the Louisville Zoo and researchers from the University of Tulsa have discovered that the world’s largest snake is capable of virgin birth or what is called parthenogenesis.

Yes, you read that correctly!

The 20-foot 200 pound reticulate python affectionately known as “Thelma” had been housed at the Louisville Zoo for more than two years prior to the clutch, without a male. In the summer of 2012, the snake had laid a clutch of 61 eggs. The eggs were covered and brooded by the coiled female for two weeks before being removed by Zoo staff for examination. It is not uncommon for a snake to lay infertile eggs, so the staff was surprised when the eggs appeared to be full and healthy instead of shrunken and discolored shells (typical of infertile reptile eggs). A decision was made to artificially incubate some of the clutch to ascertain whether the eggs were actually fertile. On Sept. 12, 2012, the first of six healthy reticulate pythons hatched with an average individual weight of 148.3 grams (5.23 ounces).

Shed skins from the mother and all six offspring – as well as other biological material – were sent to a molecular ecology laboratory in the Department of Biological Sciences at the University of Tulsa, in Oklahoma. Over the next several months, their molecular lab determined through genetic testing and analysis that all six offspring were produced by the mother alone, without sperm from a male snake. This has never been documented before in the world’s largest snake.

You may wonder why it has taken us this long to tell you about such an amazing discovery! First, it takes a lot of time to gather the necessary information and then to authenticate it and share the discovery within the scientific community.

Along the with several other authors, Louisville Zoo Curator of Ectotherms, Bill McMahan, penned a paper accepted for publication in the prestigious Biological Journal of the Linnean Soceity describing how a 20-foot female reticulate python (Python reticulatus) at the Louisville Zoo produced a live offspring without the benefit of a male snake. The paper was published in late summer 2014.

“It is a very exciting thing to be able to witness something like that first hand,” McMahan adds, “especially something that had never been documented before in this species.”

You can see mom in the HerpAquarium daily where she is on exhibit with another reticulate python. The offspring aren’t on exhibit just yet. Due to their size and exhibit space, the Zoo will likely share the offspring with other zoos within the Association of Zoos and Aquariums.

About reticulate pythons

The reticulate python is the world’s largest snake. This status is based on more than a century of documented physical evidence. Some measured specimens have exceeded 25 feet and weighed more than 300 pounds. They occur throughout tropical Southeast Asia, India’s Andaman Islands, the Philippines, Indo-China and through Indonesia’s vast Malay Archipelago

Written by Kyle Shepherd

Originally published in the Winter 2014 issue of Trunkline Magazine