The following is part of a top ten list written originally for The Times (London) by Richard Conniff from his new book (W.W. Norton).
Later, Schleser and I went down to Peru to swim with piranhas and collect fish in the wild. One day, our nets produced a slithery, eel-like little catfish with no pectoral fins or dorsal spines. Schleser identified it as the notorious , which typically swims into the gills of other fish, latches on, and pierces a gill artery to feed on the blood. The candiru is also reputed to enter the genital region of anybody dumb enough not merely to swim in the Amazon, but to urinate while doing so. When I held the candiru in my hand, it dug in with two little spines projecting down from either side of its mouth. The lore is that it uses these spines like pitons for climbing up the urethra. (This is the point in the story where you cross your legs.) I put the fish in a barrel of water and thought about putting a part of my anatomy in with it, but forebore. Instead, I peed in a cup and used it to fill a syringe, which I then injected in a steady stream into the water. The candiru gave me a 鈥淚 don鈥檛 swim in your toilet, please don鈥檛 pee in my swimming pool鈥 look, but otherwise showed no interest.