Ah, barnacles. You wouldn't really think that something with the reputation of...well, of being a barnacle, would really have an exciting sex life. I mean, they're barnacles. They are the very definition of something that is stuck in the mud. They hatch, they head to the open ocean for a few glorious weeks as whale-food, and if they survive the experience, they find a nice rock (or pier, or the bottom of a boat, or possible a whale if it wants to see the world) to call home. And never move again. Thus, the reputation of the barnacle is sealed as being possibly the most boring of creatures.
But it's not true. You see, when you're stuck to a rock, well, it's hard to meet people. If you know what I mean. You don't get out much. And so when it comes to passing on the species, barnacles have had to get creative.
The first thing that this results in is the biggest penis (relative to body size) in the world. It can be up to eight TIMES as long as the animal itself. When you're stuck to a rock, and you feel the need to breed, sometimes you have to let your penis do the walking.
(Heeeeeey, ladieeeees. Source)
And of course, you have to watch these things in action.
(Source. Did you see the one in the back just whip it out?! Barnacle porn, my friends)
You can see above how the barnacle gets it on. The penis basically hunts blind until it hits another barnacle. Then it deposits sperm into the mantle of the barnacle, which can then be used to fertilize eggs.
The longest penis in the world works well if your lover is just the next barnacle over. But what if you're all alone? What do you do?
Well, barnacles are hermaphrodites, and for many years (since Darwin, in fact) it's been thought that if they can't find someone to do for them, they just do for themselves. Self-fertilize, etc. People have often found lone barnacles with fertilized eggs, so they just assumed it happened. But while there's great video of barnacle mating, there isn't any of self-fertilization. Are barnacles just shy masturbators?
Nope, it's more than that.
Barazandeh et al. "Something Darwin didn't know about barnacles: spermcast mating in a common stalked species" Proceedings of the Royal Society B, 2013.
Continue Reading »