Do you know why you should never pee in the Amazon river? If you haven’t already heard the horrifying myth of the small, parasitic fish which swims up the urethra of unsuspecting victims, lodging itself firmly inside with the head-spikes it spears into the victim’s flesh, then you have now (sorry). According to legend, the candiru really is the stuff of nightmares, causing its victims excruciating pain, loss of…rather important body parts, and even death. But how true are the stories?
What Is A Candiru?
The candiru is a small species of catfish, native to the Amazon river basin. The name “candiru” actually refers to a number species of catfish of the genus Vandellia, but the rather revoltingly-named “penis-fish” is specifically the Vandellia cirrhosa, once known as Urinophilus diabolicus (devilish urine-lover). The “penis” variety (which shall hereafter be referred to as “candiru”, for reasons I hope are painfully obvious) are small, slender fish, reaching roughly 3-5cm in length (1-2 inches). Their bodies are fairly translucent, helping camouflage them in the murky waters they inhabit. Like all catfish, candiru possess sensory barbs on their faces, much like whiskers on a cat (hence the name). Candiru also have sharp spikes on either side of their head. Candiru are parasites, which primarily feed on the blood in the gills of larger fish. Their slender shape and head-spikes help them swim inside the fish’s gills and lodge themselves inside, causing the gills to bleed. The candiru then feeds on the blood until its stomach becomes distended and turns red, at which time it is sated, and swims away to digest its meal.
Why Are Candiru Dangerous?
The candiru is allegedly attracted to the urea and ammonia excreted by its prey’s gills. As these compounds are present in urine, candiru are supposedly attracted to that as well. The stories go that the fish smells urine in the water and tries to get to its source, and can actually swim up the urine stream outside of the water, like a tiny, revolting salmon. The parasite then burrows its way into its victim’s urethra, where its head-spikes pierce the walls of the victim’s urethra, lodging it in place. Not only is this exceptionally painful, but it is also very dangerous, and requires surgical intervention. If the fish is not removed quickly enough, there is a risk of infection, necrosis (i.e. your junk falls off) and even sepsis and death.
Human Deaths Caused By Candiru
So far, the official number of human deaths caused by the candiru is a whopping zero. The number of confirmed cases of candiru attacks or infestations in modern medical literature is likewise zero. The only alleged (and much publicized) medical case occurred in Brazil in 1997, when an unnamed 23 year-old man underwent a 2-hour surgery to remove a candiru from his penis. He claimed to have been urinating in thigh-deep water, when the candiru leapt out of the river, ascended the urine stream and burrowed into his urethra. The surgeon who removed the fish, Dr Anoar Samad, allegedly filmed the procedure using a cystoscope (a long, thin camera typically used to see inside the bladder), and preserved the candiru specimen in formalin, which he then donated to the National Institue of Amazonian Research (INPA).
However, experts have found a number of discrepancies with the case, resulting in it being labelled a hoax. Perhaps the most glaring inconsistency is that it is actually physically impossible for a candiru to swim up someone’s urine stream. Not only are these little fish not built to propel themselves out of the water, but simple fluid physics make it impossible for them to swim against both gravity and the flow of liquid in such a narrow stream. Though this is a famous part of the candiru myth, it was debunked over a century ago. In addition, the myths that candiru are attracted to the smell of urine have likewise been discredited.
The head of the candiru Dr Samad allegedly removed from his patient measured over 1cm (0.4 inches) in diameter. Considering the size of the patient’s urethra, the amount of force or other apparatus the fish would require to pry it open and force itself inside make it highly unlikely (if not impossible) that it had done so.
Dr Samad also claimed that he had clipped the candiru’s head-spikes in order to remove it, yet the specimen he provided still had all its spikes intact. He also claimed that the fish had chewed its way through the urethra into the patient’s scrotum, yet candiru do not have the right kind of jaws to achieve this.
So, How Dangerous Are Candiru?
In all likelihood, the horrifying Vandellia cirrhosa that strikes fear into the hearts of all who hear of it is actually not very dangerous at all. It is just a fragile, unfortunate little fish with a bad reputation (aww L ). Does this mean than not a single penis has ever been invaded by a candiru? Not necessarily. Stranger things have happened. Well, strange things have happened, anyway. But it is certainly not a commonplace occurrence. It would seem that the stories are just that: stories. However, there are other, larger, more voracious species of candiru than the tiny Vandellia cirrhosa in the Amazon. Could one of them be responsible for their cousin’s gruesome reputation? (possibility for other candiru articles)