Name: The Tongue-Eating Parasite
Uploaded: undefined
Duration: undefined

Gross Science

NOVA Science Trust Logo

Meet the tongue-eating isopod, Cymothoa exigua. This marine parasite feasts on a fish's tongue and then becomes its tongue. You'll never eat seafood again.

Gross science: This parasite crawls into a fish's mouth and replaces its tongue. Enough said.

Gross science: This parasite crawls into a fish's mouth and replaces its tongue. Enough said.

Produced, edited, and animated by  Anna Rothschild    Production Assistant  Allison Eck    Special Thanks  Stefanie Kaiser    Original Footage  © WGBH Educational Foundation 2013    ADDITIONAL MEDIA CREDITS    (Ceratothoa sp in Blacktail)  Host: Diplodus sargus sargus (common names: blacktail or white seabream)   Locality: Tsitsikamma National Park, Eastern Cape, South Africa  © Nico Smit

Gross science: This parasite crawls into a fish’s mouth and replaces its tongue. 

The Tongue-Eating Parasite

Tongue-Eating Parasite

Nature

The Tongue-Eating ParasitePosted: March 1, 2013Narrator: I'm about to introduce you to one of the grossest creatures on earth—it's the tongue-eating isopod, Cymothoa exigua .Isopods are crustaceans, like lobsters and crabs. This particular isopod happens to live in the ocean and is a parasite. It's a sort of…marine louse. Only it's way creepier.Anyway, the first crazy thing to know about these guys is that they're what's called "protandric hermaphrodites." That means that when they're adults, the males can become females. These isopods infest fish, so what happens is that a number of juveniles enter through the fish's gills, and all mature into males. Then, one of the isopods will become a female and that's when everything gets really freaky.The female will crawl into the fish's mouth, and attach herself to the base of the fish's tongue using her back legs. Then, she'll suck blood from the tongue until it withers and dies. This procedure is quite unpleasant for the fish, but it doesn't kill it. In fact, it starts using the parasite like a prosthetic tongue! Meanwhile the isopod just continues to hang out in the fish's mouth, sucking its blood, or feeding on fish mucus.We don't know a ton about the parasite's life cycle, but based on other mouth-infesting isopods (and yes, there are others) the female may even mate while in the fish's mouth with male isopods living in the fish's gill chamber!I know this doesn't sound real, so here is a photograph of a mouth-infesting isopod to prove it.Thankfully, these guys don't infest humans. But, they do infest fish that we eat. Cymothoa exigua has a preference for snapper, and other mouth infesting isopods prey upon mahi mahi or barramundi. So, next time you're at the grocery store, take a look inside that red snapper's mouth. You might find a tasty treat inside.

United States

Northern Mariana Islands

Puerto Rico

American Samoa

Guam

U.S. Virgin Islands

U.S. Minor Outlying Islands

US & Territories

Colossal explosions shake a remote corner of the Siberian tundra, leaving behind massive craters. In Alaska, a huge lake erupts with bubbles of inflammable gas. Scientists are discovering that these mystifying phenomena add up to a ticking time bomb, as long-frozen permafrost melts and releases vast amounts of methane, a potent greenhouse gas. What are the implications of these dramatic developments in the Arctic? Scientists and local communities alike are struggling to grasp the scale of the methane threat and what it means for our climate future. (Premiered February 2, 2022)

In the Arctic, enormous releases of methane, a potent greenhouse gas, threaten the climate.

Arctic Sinkholes

The top half of Jupiter in blue and green against a night sky

A composite image of Jupiter using images captured by the James Webb Space Telescope. Image Credit: NASA, ESA, CSA, Jupiter ERS Team; image processing by Judy Schmidt.

Explore the cosmos, delve into ancient history, and follow an extreme rescue with NOVA’s most-watched documentaries released in 2022.

NOVA’s most popular science documentaries of 2022

Four bright orange loops brand off of a dark blue blob

A transmission electron micrograph of HIV-1 virus particles (orange) replicating from the plasma membrane of an infected H9 T cell. Credit: NIAID, Flickr

Scientists have cured a handful of people of HIV by piggybacking on treatments they received for blood cancer. But does that bring a widespread cure any closer?

Transcript

Credits

Support Provided By