The parasite penetrates the gills and attaches to the base of the tongue of the spotted pink snapper. It sucks blood with claws in its front end, which leads to tongue atrophy due to lack of blood.After that, the parasite replaces the fish tongue, attaching its own body to the muscles of the stump of the tongue. Fish can use the parasite in the same way as a normal tongue. Apparently, the parasite does not cause any other damage to the host. When Cymothoa exigua replaces the tongue, some parasites feed on the blood of the host, but most of them feed on the mucus of the fish.
This is the only known case in which the parasite functionally replaces the host organ. It is currently believed that C. exigua is safe for humans, but there is a danger of being bitten if a live parasite is caught.
There are many types of Cymothoa, but only Cymothoa exigua is known to eat and replace the host tongue.
