candiru

Vandellia cirrhosa, known by the common names candiru, cañero, toothpick fish, or vampire fish, is a species of parasitic freshwater catfish in the family Trichomycteridae native to the Amazon basin where it is found in the countries of Bolivia, Brazil, Colombia, Ecuador, and Peru. The name "candiru" is also used to refer to other catfish species, including the entire genus Vandellia.

This species is known for an alleged tendency to invade and parasitize the human urethra and other bodily openings; however, despite ethnological reports dating back to the late 19th century, the first documented case of the removal of a candiru from a human urethra did not occur until 1997, and even that incident has remained a matter of controversy. Scientifically, this fish only parasitizes larger fish which it shares its habitat with; it consumes their host's blood from their gill openings, thus the candiru is a hematophagic species.