Here’s a picture of two Pseudobiceros bedfordi having sex. Looks quite action-packed doesn’t it?

The term used to describe this procedure is fun as well. It’s called “penis fencing“. Yeah, sure it is. I’m betting whatever scientist came up with that one had a pretty good sense of humour, as well as a habit of dipping into Urban Dictionary more than occasionally.

Naturally, the whole idea causes a little sniggering in the blogosphere. I reckon these are the most blogged about of all flatworms.

Pseudobiceros bedfordi are hermaphroditic, which means they have both sperm- and egg-related sex organs, and so can reproduce using either. Hermaphroditic species abound in nature. You’re not so likely to encounter Pseudobiceros bedfordi every day (for one thing, they live in a very small geographic range, near the Great Barrier Reef), but you are reasonably likely to encounter snails and worms. And here’s what they get up to when the sun goes down:

Some hermaphroditic species bide their time before declaring themselves either male or female, depending on what others nearby are up to. For example, Clownfish are initially male, until the group grows up. Then the largest one becomes female. I guess that vivid make-up is a bit of a giveaway.

Seeing as, worldwide, there are several billion earthworms and snails in existence, this must make hermaphroditic reproduction a kind of prevalent standard in nature. Best practice, if you will. In fact, seeing as there are about a million earthworms in an acre of land, and about 36,800,000,000 acres of land on earth, this means there are likely to be well over 36,800 trillion worms having hermaphroditic sex. Right now.

In other words, nearly 6 million for every man, woman, and child in the world. And that’s just the worms.

Let’s also not forget bacteria. They reproduce asexually, through binary fission. No messing around with who’ll-make-the-first-move chivalrous awkwardness there. You just reproduce yourself. And there are billions upon billions of bacteria in the world (and possibly beyond) at any one time. In fact, there are more bacteria alive in your stomach right now than there have been human beings who have ever existed. No matter what you had for dinner.

So basically, heterosexual reproduction is a fringe activity in nature. It’s the preserve of a tiny, tiny minority of creatures that exist. If you engage in heterosexual sex, you are doing it the minority way. It is abnormal — in the sense that it deviates from the norm. In fact, it’s virtually perverse.

Good to remind ourselves of that every now and then, I feel.

Brian Hughes

Brian Hughes is an academic psychologist and university professor in Galway, Ireland, specialising in stress, health, and the application of psychology to social issues. He writes widely on the psychology of empiricism and of empirically disputable claims, especially as they pertain to science, health, medicine, and politics.