u/SpillaMangBang

The tongue-eating louse (Cymothoa exigua). It is the only known parasite that completely consumes and functionally replaces a host's organ. It enters the fish through the gills, severs the tongue's blood supply, and attaches to the stub to act as a prosthetic tongue.

How the Parasite Works

Initial Invasion: Juvenile tongue-eating lice enter the fish (such as snapper, menhaden, or croaker) through the gill slits.

The Takeover: The isopod attaches to the fish's tongue using its hooked, claw-like legs and drinks the tongue's blood, causing the organ to wither and fall off.

Organ Replacement: Once the tongue is gone, the parasite anchors itself firmly to the remaining tongue stub and functions as a prosthetic tongue, allowing the fish to continue eating and surviving.

Life Cycle & Reproduction: The isopod is a hermaphrodite. The first louse to enter becomes a female. If more enter, they remain males until the female dies, at which point one of the males transitions into a female.

An elephant seal that comes on shore for molting season and completely wrecks everything!!