The female of the species gets a bit of a bum deal in some departments among the mammals. Childbirth is an effort and bleeding monthly (with occasional period poops) isn’t exactly a hoot, but genital anatomy sure did good when it sprouted the clitoris. Now, new research has found that dolphins not only join humans in possessing this pleasure point, but that it could well function in much the same way.
Published in the journal Current Biology, the findings are based upon the dissection of 11 female dolphins who no longer needed their private parts owing to the fact they had died of natural causes. That a clitoris was tucked away in female dolphin genitals wasn’t new information – dolphins’ are two to three times the size of humans' so not exactly hard to find - but the researchers on the study were hoping to unlock its physiological secrets and find out if it was… y’know… fun.
“Every time we dissected a vagina, we would see this very large clitoris, and we were curious whether anyone had examined it in detail to see if it worked like a human clitoris,” said first author Patricia Brennan, an assistant professor of biological sciences at Mount Holyoke College in Massachusetts, in a statement. “We knew that dolphins have sex not just to reproduce, but also to solidify social bonds, so it seemed likely that the clitoris could be functional.”
To answer the Big Question, they gathered samples from deceased female dolphins and took a closer look at the clitoral tissue. An early indicator that the clitoris was indeed a center of pleasure was its position within the vaginal entrance that would likely lead to stimulation during mating.
Sure enough, a closer look showed the clitoris was rich in sensory nerves and erectile bodies. The tissue was blessed with chonky nerves, some half a millimeter in diameter, with free nerve endings sitting just beneath the thin layer of skin. Here, the researchers also saw genital corpuscles — specially encapsulated nerve endings that are found on the human clitoris and penis tip and play a pivotal role in the pleasure response.
Dolphin sex was already thought to carry out functions beyond making babies as these animals will get it on year-long and appear to use sex as a way of maintaining social bonds. Female dolphins have also been observed rubbing one another’s clitorises using their snouts, flippers, and flukes — sisters doing it for themselves.
Why dolphins may have evolved this anatomical quirk can perhaps be answered by evolution. “In general, if animals experience pleasure during sexual interactions, they would seek out those interactions more,” Brennan told IFLScience. “This would translate into higher reproductive success, which is an evolutionary benefit. In the case of dolphins an added evolutionary benefit may be stronger social bonding.”
This argument would appear to be supported by the study’s revelation that the erectile tissue within the dolphins’ clitorises seemed to change with age. In the same way that human genitals become a more poignant part of our lives following puberty, it could be that as a female dolphin begins trying to attract a mate and make adult friends, developing a clitoris could go some way to helping them do it.
“The dolphin clitoris has many features to suggest that it functions to provide pleasure to females,” Brennan concluded in a statement.