>>82859423
It's a very large isopod from Antarctica. They're predators down there, eating starfish and stuff from what I remember. There's lots of cool arthropods in those waters. Colder temperatures are better for the kinds of blood that arthropods tend to have. There's also giant sea spiders down there and sea spiders use their intestines to pump their equivalent of blood around. They breath through their skin too. They're not related to actual spiders, not closely anyhow. They're both chelicerates, but sea spiders aren't even venomous and mostly suck things.
https://en.wikipedia.org/wiki/Colossendeidae