There's a parasite in the ocean that doesn't just feed on its host, it becomes part of it — Cymothoa exigua enters a fish through the gills, kills off its tongue by cutting the blood supply, and then attaches itself to the stump, living the rest of its life as the fish's new, functioning tongue

There's a parasite in the ocean that doesn't just feed on its host, it becomes part of it — Cymothoa exigua enters a fish through the gills, kills off its tongue by cutting the blood supply, and then attaches itself to the stump, living the rest of its life as the fish's new, functioning tongue

Open the mouth of a snapper lying on a fishmonger’s ice and, every so often, something looks back. Not a tongue. A pale, plated crustacean roughly the length of a thumbnail, wedged into the floor of the mouth on seven pairs of hooked legs, sitting exactly where the tongue should be and doing more or less the tongue’s job. That animal is Cymothoa exigua, an isopod, which makes it a saltwater relative of the woodlice under the pot plants. Its comm…