Sex-Reversed Cave Bugs Pack Spiny Female Penises

Sex-Reversed Cave Bugs Pack Spiny Female Penises
Here they are in action. Current Biology, Yoshizawa et al.

And you humans think you're so kinky and inventive.

Meet the Brazilian cave insects of the Neotrogla genus. We're talking four distinct species here and they mark the first documented example of an animal with sex-reversed genitalia.

That's right, as detailed in this month's Cell Press journal Current Biology, the females "insert an elaborate, penis-like organ into males' much-reduced, vagina-like opening" during 40-70 hour lovemaking marathons.

"Lovemaking" is a bit anthropomorphic. This is, after all, the brutal world of insects. As the team of Brazilian and Japanese researchers discovered, the female inserts her phallic "gynosome" into the male and then the sex organ inflates, hooking a bevy of spines into the male's body to anchor the two insects together.

Scientists have observed sex reversal in other organisms, but this marks the first time they've uncovered the female penis. Let's have a look at the "gynosome" on its own:

The female penis of N. aurora.
Current Biology, Yoshizawa et al.

The gynosome doesn't deposit material like a male penis. Instead, it receives sperm as well as capsules of nourishment -- sort of gift or bribe to encourage lots of mating. And this very act of gift-giving, the researchers argued, likely drove the evolutionary development of the female penis to begin with -- a phallic arms race if you will.