Well……this is disgusting :U Cymothoa exigua, or thetongue-eating louse, is aparasiticcrustaceanof the familyCymothoidae. This parasite enters fish through thegills, and then attaches itself at the base of the fish’s tongue. The female attaches to the tongue and the male attaches on the gill arches beneath and behind the female. Cymothoa exigua extracts blood through the claws on its front, causing the tongue toatrophyfrom lack of blood. The parasite then replaces the fish’s tongue by attaching its own body to the muscles of the tongue stub. The fish is able to use the parasite just like a normal tongue. It appears that the parasite does not cause any other damage to the host fish. OnceC. exigua replaces the tongue, some feed on the host’s blood and many others feed on fish mucus. This is the only known case of a parasite functionally replacing a host organ.