Friday Weird Sex Blogging – Penis Fencing

Penis_fencing_insemination.jpgSome flatworms, for instance these pretty Pseudobiceros hancockanus, engage in penis fencing. Both individuals are hermaphrodites, i.e., have both male and female organs. The penis is white, pointed and two-headed. Both individuals are trying to inseminate the other. The one who is inseminated has to bear and lay eggs – a more expensive proposition. The one who “won” the fencing bout and did the insemination can move on and fence some other guys and on and on, “fathering” many progeny until happenning onto a better fencer, getting inseminated, and spending the rest of the life as “mother”.

4 responses to “Friday Weird Sex Blogging – Penis Fencing

  1. for real, ‘hancockanus’? it strains one’s capacity for belief…
    why oh why is there not a video?

  2. I wonder how that behaviour would combine with the morphology of the New Zealand multivirile flatworm – 220 odd penises either side would make for some interesting fights

  3. Yup, scientists have a sense of humor and often use it when naming species.
    David, thank you – that one goes into my folder of ideas for future installments of Friday Weird Sex Blogging.

  4. Friday Ark #94

    We’ll post links to sites that have Friday (plus or minus a few days) photos of their chosen animals (photoshops at our discretion and humans only in supporting roles). Watch the Exception category for rocks, beer, coffee cups, and….? We will add you…