Penis Discovered in Female Insect: Novel Structure in Evolution


While studying the Brazilian cave insects, researchers to their surprise discovered a penis like genitals in females and organ similar to a vagina in males. For the first time they have noticed, such an extreme switch of sex organs and have dubbed the newly revealed penis of the female insects as “gynosome” and “phallosome” for the vagina like organ in male insects. 

The group of insects known as Neotrogla was first discovered in a Brazilian cave some 20 years ago, by biologist Rodrigo Ferreira from the Federal University of Lavras in Brazil. However, Kazunori Yoshizawa, a Japanese entomologist from Hokkaido University, found this new variety of Neotrogla insects. While inspecting the cave, he found these new insects in the process of mating. Yoshizawa attempted to separate the two mating insects and found that the penis like structure was so firmly holding its counterpart that it tore the abdomen of the partner, instead of getting separated.

Later, while studying the insects, Yoshizawa found that it was female who possessed the penis like structure during the mating process. A female with a penis is entirely a unique structure to observe in recent times, said he.

In the animal kingdom, the presence or absence of the sex organs or sex chromosomes is not the deciding factor whether an insect of species is a male or a female. Rather the sex of the insects is determined by the size of its gametes that is sperm in males and oocytes in females. According to the rules of biology, the gametes produced by the females are larger than that produced by males. Likewise, females also evolved to have penis, which they employ for fertilizing eggs with small gametes from the phallosome of the male.

Yoshiwaza observed that during copulation, female introduce their penis called gynosome inside the male vagina known as phallosome. After entering the male vagina, the membrane of the gynosome inflates, which has spines that firmly anchor the insects together. The female uses its gynosome to derive nutrients and sperm from the males. And this association of the male with the female is so strong, that it can tear open the abdomen of male if they do not get separated properly. The mating may last from 40 to 70 hours long. The researcher postulates that sex reversal may have evolved by the insects to tackle the cave environment, which is usually harsh, and nutrition deficient.

Researchers suggest that during the long mating duration, female using gynosome receives healthy and large amount of ejaculation from the males. And as the female holds the male so strongly researchers believes that during the entire process males remains passive, because any resistance can cost them their lives and it seems they are forced and controlled by the females.

However, how and what made these female insects to develop penis is still a mystery for researchers to unlock. Places like caves and caverns are explored so little, who knows what bizarre animals are yet to be discovered.

Explore further

Leave a Comment