Cymothoa exigua (lice) - eater is language, one of the most unusual in the world of parasites.
3-4 cm crustacean penetrates into the body of the fish gills and alternation bites into the language of fish.
Language in time dies due to lack of blood after parasite replaces it with his body.
Fish parasite uses as a common language.
This is the only known case of a parasite replaces the body with all its functions.