A Tongue-Eating Parasite Makes For A Terrifying Science Article
Kory Evans/Twitter
A biologist found a parasitic tongue-eating louse inside one of his fish specimens.
When ichthyologist Kory Evans was scanning a fish specimen for his research project, he found a disgusting surprise: a tongue-eating louse had burrowed itself inside the fish’s head masquerading as its new “tongue.”
Evans was startled but not entirely shocked.
“It looked like it had some kind of insect in its mouth,” Evans recalled. “Then I thought, wait a minute; this fish is an herbivore, it eats seaweed. So I pulled up the original scan, and lo and behold, it was a tongue-eating louse.”
The tongue-eating louse, otherwise known as “fish lice,” has previously been recorded in the wild. These parasites are marine isopods or small crustaceans that invade the fish’s body through its gills then latch onto its tongue to feed.
The lice suck the fish’s tongue dry until it atrophies and drops off. Then, the parasitic creature burrows inside the fish’s mouth where it essentially becomes the animal’s new “tongue.” There are 380 species of fish lice that exist in the world.
The fish louse found by Evans, who works as an assistant professor in the Department of BioSciences at Rice University in Houston, Texas, had made its home inside the mouth of a herring cale (or Odax cyanomelas) wrasse. He uncovered the tiny stowaway while x-ray scanning the wrasse for his database-building project.
“[Wrasse] have a second set of jaws in their throat, like in the movie Alien,” Evans said. “Wrasses can swallow a snail, and then they can actually generate enough force with the second set of jaws to crush the shell up in their throat.”
Evans uses his social media to share the progress of his research project. He also shared the fascinating discovery online where the parasite photo promptly went viral.
Despite the gruesome parasitic process, the relationship between the fish louse and its fish host is symbiotic as it benefits both creatures — the louse functions like a real togue for the fish while the fish acts as a source of food as it continues to feed on the animal’s mucus.
The relationship, though bizarre, can last for years.
The story of the tongue-sucking fish lice made for one of the most disturbingly fascinating science stories of 2020.
