Body-Snatching Roly Poly of the Deep | Tongue-Eating Isopods

[Music] ever hear the saying cat got your tongue in some areas of our oceans there's a special type of parasite which takes this simple idiom to the most [Music] extreme in the gulf of california the gulf of guayaquil in ecuador and in some regions of the atlantic ocean there exists a family of around 380 species of crustaceans which target a few fish species by infiltrating the gills and latching onto the tongue this family is called the cymothoide the cymothoide belongs to the isopada order which means they're essentially aquatic pearly pulleys much more closely related to the giant isopod of isopod hours fame these parasitic isopods differ tremendously from the little armadillo-like critters you find in the soil around your house they're parasitic but not just like your average parasite either you see this species is a protandrous hermaphrodite a protandrous hermaphrodite is an organism which develops as a male but can later reproduce as a female since nature is freaky like that there are a few different types of protandrous hermaphroditism a protandrous sequential hermaphrodite reproduces early on in its life cycle as a male and later on as a female protandist hermaphroditism with overlap covers an organism which develops early on in its life cycle as a male and reproduces and then later on changes into a female and reproduces again but with an intervening overlap between male and female reproduction the third protandrous simultaneous hermaphroditism consists of early pure male reproduction and later development into a hermaphrodite form with both genitalia these tongue-eating isopods fit into the protandrous hermaphroditism with overlap category the process is simple really a juvenile usually of the species cymothoa exagwa swims into the gills of a fish it begins to mature into a male the magic begins when more than one isopod enters the fish's gills when more hitchhike the first isopod receives pheromones which tell its body to change and its brain to migrate to a different part of the fish's body it wiggles its way through the gills and into the fish's throat and mouth until it rests on the tongue it uses its seven pairs of spine-tipped legs to firmly grasp the fish's tongue upon adhering itself to the fish's tongue it slices into it with its mouth parts and drains the tongue of its blood the atrophied tongue dies and falls off leaving a heavily reduced nub of tongue muscle perfect for the isopod to attach itself to the isopod then becomes the fish's new tongue it is by this time that the isopod has transitioned into a female any incoming juveniles to the fish host are forced to stay male by the presence of the female if the female dies or there aren't any in the fish yet the new juvenile male will metamorphose into a female and complete the cycle i've laid out the adult female of the cymothoa exag species is now a fully functioning tongue for the fish host the isopod goes along for the charade and lets the fish use its body to grind food against the tiny teeth which line the roof of the fish's mouth that's true dedication to your lifestyle right there mad respect the whole process is the only known instance in all of nature of a parasite which willingly becomes a functioning organ of a host animal the species cymothoa exoga targets around eight species of fish but only with the rose snapper does it become a fully functioning tongue it is as the fish host's tongue that the female isopod stays for the remainder of her life she eats sleeps poops reproduces and dies as the tongue as she grows she molts like any other exoskeleton wearing arthropod while feeding on the quickly atrophying fish tongue her mouth parts aren't serrated chopping blades nor recurved fangs they're more like stiletto-shaped lances all five of the mouthparts easily slice open the tongue's tissues and operate together as one large dangerous soda straw to suck up all that delicious delicious tongue blood from the wound it made to help this go smoothly they're convergently evolved to secrete anticoagulants like most parasites to stop the fish's blood from clotting why and how could such a relationship evolve why become a fish host's tongue to become a tongue and a fully functioning one at that is to keep your host alive this relationship very probably evolved specifically for the parasite to keep the host alive for a long period of time it gives the parasite a longer supply of blood and more time to rear her young it allows the host to stay alive so long as the parasite lives but then comes the catch so long as the parasite lives the female form now a permanent residence of the fish's mouth loses her ability to swim and clings to the tongue stub with her rearmost three or four pairs of legs once the tongue has been sucked dry and falls away the female is devoid of a food supply as her blood-sucking babies continue to grow into strong independent young isopods she lives entirely on stored energy reserves and slowly starves to death many researchers aren't certain exactly when the young are released from the host fish or how they find new hosts one hypothesis offered up is that the mother isopod waits until the host has begun to school with other members of its species mama isopod then releases her spawn upon the unsuspecting fish shoal so her babies have a higher chance of finding a nice cozy fish to snuggle up in remember that scene in titanic when the band goes down with the ship what happens next to the tongue eating allows his life cycle is basically that but with sex changes and tongue eating so not much like that at all i guess anyway with the completion of her duties the mother isopod no longer needs to exist having already lost her ability to swim and succeeding in making her swarm of baby parasites she has one of a couple options she can let go of her host and leave get swallowed by her host or stick to her tongue nub until the bitter end either way the female is out of the picture and soon so is the host now without a tongue the host fish doesn't survive and quickly starves to death this is one of the rare occurrences of true parasitism the parasite takes from the host and without it the host dies the fish is sacrificed for the sake of the parasite what a way to go it remains a mystery as to why the cymothoa exaqua isopod goes so far in the parasitism of the rose snapper but not any other host species remember this specific species of tongue-eating laos parasitizes eight species of fish but only with the rose snapper does it become a fully functioning tongue within the mouth of its other host species the isopod just sucks from the tongue it doesn't destroy and replace it some researchers think this may have something to do with the tongue of the rose snapper perhaps the tongue is more susceptible to parasitism because of low vascularization compared to other species more researchers needed to answer this question i think the adaptive advantages of this lifestyle are crystal clear the mother gets a steady meal and a perfectly safe bunker for herself and her babies her purpose is to pass on her jeans to the next generation if her jeans are stronger than others they will do just that it just so happens that hunkering down in a fish's mouth and becoming a tongue is just a ticket to successfully passing on your genes if you're a tongue-eating isopod that is with her mission complete she simply goes down with the ship the poor poor red snapper though all it gets in this relationship is a weird prosthetic it didn't ask for blank stares from a show and a premature death i have discussed the life cycle of cymothoa exigua at length but this is the only species among hundreds which do similarly grotesque things to fish as a whole the cymothoidae are all parasitic some live in fresh water as well as they do in salt water many start out their juvenile form by attaching to the outside of a fish host because this is their first host it usually isn't the exact host species they need once they detect that host species they detach from the first host and attach to their new one then their life cycle begins as one might expect from evolution there are different methods which led to the tongue replacing lifestyle many of these steps were successful as well and have therefore survived in different species which remain in today's ocean fauna that's why you'll find the tongue replacing isopod along with species which bore directly into a host's muscles species which remain in the gills only some which stick to the host's fins and more is there anything these fish can do about their parasites yes some species have formed mutualistic relationships with certain species of shrimp like ancillomenes petersoni the host fish visits a cleaning station where the shrimps live the fish lets the shrimps in its mouth and doesn't eat them the shrimp then cleans the fish of parasites and makes sure to kill and feed on the tongue-eating laos whether or not the shrimp gets to the parasite before it has done its damage is a shot in the dark for the host fish it just has to make sure it gets checkups frequently and on time these parasites have been recorded as a common pest in fish farms just like in the wild they infect the fish and attach to their tongues in captivity the parasites cause a lot more damage including tongue tissue damage growth defects anemia decrease in mean weight and size and increased mortalities such effects do occur in wild fish but since captive fish are well captive they can't exactly go anywhere and come into contact with agents which might help them survive better or get themselves a good deep clean from a helping shrimpy hand thankfully these little buggers pose no threat to humans i wouldn't go ahead and wrangle one though firmly grasping one of these critters will probably prompt it to take a chunk out of your hand that being said the gruesome reality of the relationship between parasite and host are a perfect kernel to spin a story from just such a story was made into the 2012 film the bay director barry levinson tweaked the real animal into a mutant form which goes through the same life cycle but this time in humans on top of the usual tongue replacing thing these fictional mutant isopods reproduce exponentially within their human host they affect humans by causing rashes irritants and decomposing gashes on the outer dermis somewhat like a zombie eventually the person affected dies when the isopods burst out of their host presumably find a new host and reproduce some more the movie takes place in a small quiet chesapeake bay town wherein the story is told via found footage from a news camera team which covers the event as it unfolds turns out the isopods were mutated from pollution of dumped chemicals from a local chicken farm not exactly realistic but doesn't need to be if you're interested in the film and its themes i highly recommend checking out ryan hollinger's video on it the cymothoa exigua species was the subject of a lawsuit against the large supermarket chain in puerto rico since they inhabit the mouths of rose snappers which are distributed worldwide many of them are bound to have these parasites the customer in the lawsuit claimed to have been poisoned from consuming an isopod which was overlooked inside a fish isopods contain no known toxins or poisons which would have an effect on humans and on the contrary many species of isopods are routinely consumed as part of some people's diets therefore the lawsuit was promptly dropped talk about leaving a bad taste in the mouth what more could we find to creep ourselves out next stay tuned subscribe to consume some delicious content trash like button scrape out a comment and blast the notification bell just so you're in the know with everything edge thanks for watching a very special thanks to my patrons dinosaur natty cat ed perez steve bradshaw they spencer jacob spencer dana manchester clayton maxfield antron if you'd 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Channel: EDGE Science

Views: 23,103

Keywords: paleontology, cryptozoology, science, education, fossils, EDGE, zoology, natural history, scicomm, geology, jurassic world, jurassic park, evolution, documentary, dinosaur, dinosaur game, rocks, crystals, stratigraphy, paleoart, natural history museum, animal, nature, science education, mystery, biology, united states

Id: kJhOZqZU5YA

Length: 13min 44sec (824 seconds)

Published: Thu Mar 18 2021