Python babies the result of 'virgin birth,' zoo confirms
The Louisville Zoo posted this image of 'Thelma,' the reticulated python on their Facebook page on Thursday, Oct. 23, 2014.
Angela Mulholland, CTVNews.ca Staff
Published Friday, October 24, 2014 2:58PM EDT
A mysterious case of reptilian “immaculate conception” at the Louisville Zoo in Kentucky has been solved.
A female reticulated python named Thelma mysteriously produced six baby snakes at the zoo in 2012. Staff couldn’t understand how the babies came about since Thelma had not had any recent contact with a male.
Bill McMahan, the zoo's curator of ectotherms, told National Geographic his staff assumed the birth was the result of the female’s ability to store sperm.
Now, research has confirmed the babies were the result of a little-understood process called “parthenogenesis.”
In parthenogenesis, eggs inside a mother become embryos without male fertilization. Such forms of “fatherless reproduction” occur frequently among plants and insects. But incidents among reptiles and amphibians have been rare.
In recent years though, there have been a number of documented incidents of parthenogenesis among a growing list of species.
Thelma, who measures more than six metres long, suddenly produced 61 eggs two years ago. Six of the snakes survived.
Researchers were able to study the genetics of the six, and found only Thelma’s DNA among them, confirming parthenogenesis. Their findings appear in the Biological Journal of the Linnean Society.
The zoo displayed a photo of Thelma and her offspring on its Facebook page Thursday, writing that the births are the first ever documented case of “virgin births” among reticulated pythons, which are constrictors from southeast Asia that are the largest snakes in the world.
“We are very proud to have contributed to the canon of what the world knows about this species,” zoo staff wrote.
In 2008, scientists confirmed through DNA research that a female Atlantic blacktip shark at the Virginia Beach Aquarium had also become pregnant through parthenogenesis.
A similar pregnancy was documented the year before at a zoo in in Omaha, Neb. when a baby hammerhead shark was born in a tank with three potential mothers, none of whom had contact with a male hammerhead for at least three years.
And in 2007, five babies hatched from eggs laid by a komodo dragon at the Chester Zoo in England that also had had no contact with a male.