The Vampire Fish between reality and myth

The Vampire Fish or Candirú or Canero (Vandellia cirrhosa) is a freshwater fish belonging to the Catfish group. The species grows only to being one to two inches in length and four to six millimeters wide. It is shaped like an eel and is almost completely transparent, making it almost impossible to see in the water. A fast, powerful swimmer, the fish is smooth and slimy, with sharp teeth and backward-pointing spines on its gill. The Candiru is primarily found in the Amazon and Oranoco rivers and has a reputation among the natives as the most feared fish in its waters.

Parasitism

The candirú parasitizes other fish. It swims into the gill cavities of other fish, erects a spine to hold itself in place, and feeds on the blood in the gills, earning it a nickname as the “vampire fish of Brazil.” In 2004, research determined that candirú do not suck blood, but rather latch on to an artery and have blood pumped into them.

Commonly referred to as the “willy fish” by natives, it is feared because it is attracted to urine, and if the bather is nude it will swim into an orifice (the vagina, rectum, or even the penis—and deep into the urethra) and because of spines protruding from the fish, it is almost impossible to remove except through surgery. The fish locates its host by following a water flow to its source and thus urinating while bathing increases the chance of a candirú homing in on a human urethra. Natives have also been known to bathe facing the current, as doing so would decrease the chances of the organism lodging itself in the rectum. Other orifices such as the penis or vagina are covered up with the use of hands.

A well-circulated myth is that the candirú is capable of swimming up the stream of urine in mid-air to a victim standing on shore or a boat. This is physically impossible as the maximum swimming velocity of the fish is opposed by the downward velocity of the urine stream, and the further impossible act of the 5-14 mm wide fish maintaining position and thrust within a 2-7 mm wide column of fluid. Furthermore, when humans urinate the stream breaks apart instead of staying together as a perfect stream.

A traditional cure involves the use of two plants, the Xagua plant (Genipa americana) and the Buitach apple which are inserted (or their extract in the case of tight spaces) into the affected area. These two plants together will kill and then dissolve the fish. More often, infection causes shock and death in the victim before the candirú can be removed. Though there have been documented candirú attacks on humans, there is no evidence the fish can survive once inside a human. It was recently sought after by Nick Baker, a wildlife specialist on British TV in a series about the world’s strangest animals.