Tongue eating louse, even creepier than a tongue ring

     My last two posts have been about the perplexing problem of intestinal parasites, but after much 
research I have stumbled upon a different kind of parasite. It's quite a disturbing because it over takes over the tongue of a fish and becomes that organ.
This parasite is called a Cymothoa exigua or tongue eating louse (louse is plural for lice), and it is just as disgusting as it sounds. Luckily for us humans it only affects fish, unluckily for fish it only affects them.  

     This parasite enters the fish's mouth through the gills attaching to the base of the tongue. It draws blood using claws on the front three legs and the parasite begins to grow very large. After an unknown amount of time passes of feeding on the fish's tongue, less and less blood is able to get to this organ which eventually leads to the tongue falling off. The parasite then attaches the area where the tongue fell off too its own body and begins to function as the fish's tongue. It does not actually cause any harm to the fish, some scientists believe it may increase the natural mortaility rate in the first few years of the parasite taking over though.


     I know this is not exactly an intestinal parasite, but I find it infinitely interesting that this natural phenomena happens. It is the only known case of a parasite becoming an organ in the host it has inhabitated, which leads us to continue to marvel (and get the nasty shivers) at this incredible happening that occurs in nature.

Studies on the biology of the parasitic isopod Cymothoa exigua Schioedte and Meinert, 1884 and its relationship with the snapper Lutjanus peru (Pisces: Lutjanidae) Nichols and Murphy, 1922, from commercial catch in Michoacan. Ruiz L., A | Madrid V., J Ciencias marinas. Ensenada [CIENC. MAR.]. Vol. 18, no. 1, pp. 19-34. 1992. 

R. C. Brusca & M. R. Gilligan (1983). "Tongue replacement in a marine fish (Lutjanus guttatus) by a parasitic isopod (Crustacea: Isopoda)". Copeia : 813–816.

Ernest H. Williams, Jr. & Lucy Bunkley-Willliams (2003). "New records of fish-parasitic isopods (Cymothoidae) in the Eastern Pacific (Galapagos and Costa Rica)".Noticias de Galápagos (62): 21–23.

"Tongue-eating bug found in fish". BBC News. September 2, 2005.