Writes Ed Yong on Discovery News:
To become both a lover and a fighter, the male spider Nephilengys malabarensis snaps off his penis inside his partner while they have sex. He becomes better at fending off other males who try to mate with her, because his now-lightened body can fight for longer without tiring. And while he’s playing the guardian, his detached genitals can continue pumping sperm into the female. Through self-castration, he gets more stamina, and he gets more stamina.
I first wrote about the self-castrating spider a few months ago. Then, Daiqin Li from the National University of Singapore confirmed that the severed penis continues to pump sperm into the female. That allows the newly minted eunuch to fertilise her remotely, while also blocking the way to other males…
Read More: Discovery News