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Fun Science Friday – First Female Penis

Happy Fun Science Friday.

You did not mistakenly read the title, today we bring you the discovery of the first female penis in the animal kingdom.

Mating insects of the genus Neotrogla. Photo Credit: Current Biology / Yoshizawa et al.

Mating insects of the genus Neotrogla.
Photo Credit: Current Biology / Yoshizawa et al.

Yoshizawa, from Hokkaido University in Japan, and his team of researchers documented this phenomenon of sexual role reversal in 4 species of rather unassuming insects in Brazil’s Peruaçu River Valley.  When insects of the genus Neotrogla mate, the female mounts the male and penetrates his vagina-like opening with her penis.

Magnification of the female penis of Neotrogla.  Photo Credit: Current Biology / Yoshizawa et al.

Magnification of the female penis of Neotrogla.
Photo Credit: Current Biology / Yoshizawa et al.

Now you may be thinking,  if the female has the penis,  these researchers have simply mistaken the male for the female. In biology, sex is determined not by the sexual appendage, but by the size of the gametes – sperm in males and oocytes in females. As a rule, females contribute more energy to the production of larger gametes than males.

Magnified copulation of Neotrogla.  Photo Credit: Current Biology / Yoshizawa et al.

Magnified copulation of Neotrogla.
Photo Credit: Current Biology / Yoshizawa et al.

Mating can last for 40-70 hours due to the female’s inflatable, spiny penis attaching to the internal tissue of the male. During this time period the female collects the male’s sperm which she uses for fertilization. This strategy of reproduction is quite remarkable as the evolution of the female penis has no precedent.

So it seems, anything goes in a cave. ;)

To read more about the work of Yoshizawa and his team, you can see this study published in the journal of Current Biology.