The researchers found the first evidence of a two-part genitalia, called the hemichlitoris, in all nine female snake species they studied.
14 December 2022
Female snakes have not one but two clitoris, according to research that documents the first official evidence of genitalia in snakes. This bipartite clitoris, called the hemiclitoris, is found in at least nine species of snakes.
“There’s so much known about the male snake genitalia, but not that much is known about females – nothing really is known,” says Megan Folwell of the University of Adelaide in Australia. Previous research was “all over the place on whether the snake clitoris exists.” To end the discussion, Folwell and his colleagues began examining specimens of female snakes from the University of Michigan’s zoology collection.
It doesn’t require much research, Folwell says. “You peel off the skin and it’s right in front of you,” he says. They found hemiclitor in all nine species they looked at, and they were all located on the underside of the snake’s tail.
Dissections and micro CT scans revealed a range of hemiclitoris sizes and structures across species. console viper (Agkistrodon bilineatusA pit viper native to Mexico has the largest hemiclitoris of the nine species, while the brown snake of the Australian species Ingram (pseudo word), has the smallest. Among the other species they studied were the common death adder (Acanthopis antarcticus), Guatemalan milk snake (Lampropeltis abnormality) and carpet python (Morelia spilot). Folwell says he suspects most, if not all, female snake species have hemichlithritis.
The team also found that, like the bipartite hemipenes of male snakes and lizards, the females’ hemicultors are composed of sensitive nerves and erectile tissue. Unlike hemipenes, however, females’ hemicultors lack spines and hooks, which are thought to aid in mating.
The study “provides indisputable evidence that [the clitoris] “It’s out there, it’s big and complex,” says Richard Shine of Macquarie University in Australia, who was not involved in the study. “It’s a huge step forward in our understanding of sexual anatomy in reptiles.”
“I think the female side of things is getting a little lost,” Folwell says when it comes to examining animal genitalia. “But now there’s a great community of scientists studying the female genitalia, which is really exciting.”
Journal reference: Proceedings of the Royal Society BDOI: 10.1098/rspb.2022.1702
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