that parasite story

Awhile back, I posted about Redmond O'Hanlon, who I adore, and Justine requested that I tell the verboten parasite story that Christopher wants me to stop bringing up over meals. So, I'm finally getting around to it, but instead I'm going to let O'Hanlon tell it, from this Nexus interview (which has lots of other fascinating ookiness in it):

Now, before you became fascinated with the depths of the ocean there was a fascination with Africa. I understand there's another little fish over there which goes in through another orifice.

Ah, yes, that was a fascination with jungles in general, but that's actually in South America. You have to remember that when Gondwanaland, when South America was linked to Africa, the Niger was part of the Amazon. Then up came the Andes and blocked the river off, so it reversed its flow. So it had a very, very long time for some very interesting parasites to evolve. Now this is a tiny catfish called the toothpick fish, and in fact I talked about it as a joke on a television program in the UK. And the serious scientists went out and they took some special fine mesh nets with them and found these fish are absolutely everywhere, the candiru, or the toothpick fish.

So say you've had too much to drink, and you dive in and you take a pee this little fish locks onto the stream of urine and in fact swims very, very powerfully. It's got a terrific burst of energy in the tail muscles, and it will make its way straight up your urethra and put out six retral spines on either side and does a half turn, and hangs in there. And the pain apparently is spectacular and there's nothing you can do. You have to get to a hospital before your bladder bursts and, in your best Portuguese, you have to ask the surgeon to cut off your penis.

That fish lives where?

All over the Amazon Basin. But we fooled it. I'm very proud of this. This really is a contribution to science. It comes under science I think. This is a cricket box, which you'd understand here, but the piece of genius is I put a tea strainer on the front of it, and then I found they enter all your other orifices as well, so I gave up. It's best not to go for a swim in the Amazon.