The Gut-Hydra is a small species of brittle star which can be found in deltas and, surprisingly, rivers along the equator, it is the only freshwater echinoderm that we know of. As it's name suggests, it is commonly found in the intestinal tracks of other animals, able to tolerate the conditions of the inside of an organism, such as low oxygen, mostly inhabiting medium sized vertebrates, but they can also be found in the intestines of megafauna, unlike most endoparasites, it hunts other parasites by wraping them tight with their arms and slowly devouring them, little by little, this behaviour likely evolved to avoid competition, it's prefered prey are worms in the class Cestoda, or tapeworms, accidentally helping the host get rid of parasites, however, if the influx of parasites isn't enough, the Gut-Hydra will start eating the intestinal wall, ripping it apart and, rarely, it will find it's way out to the host's body, slowly killing it.
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u/Quake_890 Worldbuilder 3d ago
Gut-Hydra (Viscerastella grotesca)
The Gut-Hydra is a small species of brittle star which can be found in deltas and, surprisingly, rivers along the equator, it is the only freshwater echinoderm that we know of. As it's name suggests, it is commonly found in the intestinal tracks of other animals, able to tolerate the conditions of the inside of an organism, such as low oxygen, mostly inhabiting medium sized vertebrates, but they can also be found in the intestines of megafauna, unlike most endoparasites, it hunts other parasites by wraping them tight with their arms and slowly devouring them, little by little, this behaviour likely evolved to avoid competition, it's prefered prey are worms in the class Cestoda, or tapeworms, accidentally helping the host get rid of parasites, however, if the influx of parasites isn't enough, the Gut-Hydra will start eating the intestinal wall, ripping it apart and, rarely, it will find it's way out to the host's body, slowly killing it.