Scientists discover four insect species with reversed organs such that the female penetrates the male.
According to a study published today in the journal Current Biology, researchers have confirmed that four species of insects discovered in caves in Brazil have sex-reversed genitalia, with the females having what the study's authors call "a highly elaborate, penis-like structure" that penetrates the male's non-protrusive, vagina-like sex organ.
“There’s nothing that [this] can be compared to,” study co-author and professor at the Federal University of Lavras in Brazil Rodrigo Ferreira, told National Geographic. “This elaborate female penis is completely unique.”
While there is no answer yet to why these insects, which are of the Neotrogla genus and live in pitch-black caves in Brazil's Peruaçu River Valley, evolved to have this peculiar reversal, The Verge breaks down what, exactly, qualifies this bug as a female with a penis:
Contrary to popular belief, the presence or absence of certain sex organs isn't the determining factor when deciding which animal of a species is female and which is male. In fact, biologists don't use sex chromosomes either. They actually rely on the size of an animal's gametes — sperm in males and oocytes in females. As the rule goes, females are the sex that contribute the largest gametes, whereas males are the sex that contribute the smallest gametes and therefore expend the least amount of energy on producing these cells. So, in this particular instance of sex-role reversal, the convention still applies: the female in these species of insect produces the largest gametes — egg cells. She simply also happens to sport a penis that she introduces into the male's vagina during copulation.
Also of note, the insects' mating ritual lasts an astounding 40 to 70 hours, due to the way that spines on the female's penis hook into the male while she gathers the seminal fluid from his vagina.
"It is very likely that entire mating processes are controlled actively by females, whereas males are rather passive," study co-author Yoshizawa Kazunori, an entomologist at Japan's Hokkaido University, told The Verge.
There is no word in the study whether or not the female bugs say, "yeah, you like that?" or "who's your daddy?" while mating.
Image via Yoshizawa Kazunori.