This fish is called the candiru and is a member of the genus Vandellia. The candiru is found in the Amazon region of South America and is a type of catfish. The fish is actually parasitic. It uses spines located on the covers of its gills to attach itself to the gills of other, larger fish. They can be traced back to the 19th and early 20th centuries.
Would the candiru fish really eat your genitals?
The Dreaded Candiru
Irmgard L. Over the last years, a little South American fish with alleged unsavory habits has become the stuff legends are made of. With growing visitor numbers to the Amazon basin, the question of whether the animal poses a threat to the many travelers to the region arises. The reference lists of all obtained sources served to refine the search, including the original historical writings where obtainable.
Is There Really a ‘Penis Fish’ That Swims up the Urethra?
The story is that the fish swims up a stream of urine into a man's penis, then eats it from the inside. But is there any truth to it? Of all the denizens of the Amazon basin, there is none more feared than the tiny fish known as the candiru. Since coming to the attention of science in the early 19th century, this creature has occupied the very darkest recesses of the popular imagination. The reason for this is the candiru's supposed habit of entering the human penis, lodging itself in place with sharp barbs, and feasting on it from the inside — a horror story that is enough to keep your legs firmly crossed for days.
Vandellia cirrhosa, AKA Candiru. I have heard about a tropical fish which can detect traces of mammalian urine in the water and will enter the urinary tract of the mammal. Is this true?