After years of neglect, scientists say they've finally found the female snake's sex organ
It took more than a century, but scientists finally found it – the female snake's clitoris.
A new study published in Proceedings of the Royal Society B Journal on Wednesday revealed that after years of scientists studying the genitalia of male snakes and incorrectly identifying the females' sex organ, researchers proved that the female genitalia not only exists, but could play an important role in longer and more frequent mating.
"Across the animal kingdom female genitalia are overlooked in comparison to their male counterparts," Megan Folwell, a Ph.D. candidate at Australia's University of Adelaide and the study's lead author said. "Our study counters the long-standing assumption that the clitoris (hemiclitores) is either absent or non-functional in snakes."
The genitalia of male snakes and lizards – a group known as squamates – has been studied extensively since the 1800s, three of the study's authors wrote earlier this year. They noted scientists have uncovered all kinds of information about the male genitalia, called a hemipenis in squamates, including about the size, shape and even whether it has spines.
But ever since the snake penises were discovered, female snake genitalia has been "conspicuously overlooked," the new study says, with many assuming for years that the visible organs were underdeveloped hemipenes or scent glands. Even when the clitoris was identified in lizards, the study says, it was assumed that their purpose was to help stimulate males.
To paint a more accurate picture of the female snake's anatomy, Folwell and a group of international scientists analyzed adult females of nine snake species from different areas of the world, including Australia, Central America and South America.
"I know it [the clitoris] is in a lot of animals and it doesn't make sense that it wouldn't be in all snakes," Folwell told the BBC. "I just had to have a look, to see if this structure was there or if it's just been missed."
And they found that the animals have not one, but two individual hemiclitores separated by connective tissue, providing the first complete description of the animal's clitoris, known as hemiclitores in squamates. Unlike lizard clitorises, the study says, the snake sex organs don't have spines or retractor muscles, but come in all kinds of sizes and in slightly varying locations.
They also discovered that the snakes' clitorises have nerve bundles and fibers that could indicate tactile sensitivity, "similar to the mammalian clitoris," the study says. If male snakes were to provide sensory stimulation to the organs, it could "elicit female receptivity" and even help promote longer and more frequent mating, as well as better rates of fertilization, researchers said.
"We found the heart-shaped snake hemiclitores is composed of nerves and red blood cells consistent with erectile tissue — which suggests it may swell and become stimulated during mating," researcher and University of Adelaide professor Kate Sanders said. "This is important because snake mating is often thought to involve coercion of the female — not seduction."
More research is needed about hemiclitores, Folwell said, but their discovery is an essential first step.
"We are proud to contribute this research," she said, "particularly as female genitalia across every species is unfortunately still taboo."