Tudeep Sucker
Due to high predation by Carpotesta Devoratori, some Crystalsuckers migrated to a new area in an attempt to escape their primary predator. Because of the extreme conditions of the ridge, the Crsytalsuckers changed significantly in both lifestyle and appearance. The pitch-black abyss has caused the Carpotestan to lose all pigment, additionally, it has lost its unnecessary lower eyes and developed compound eyes with the added ability to perceive IR, so as to find its primary prey nearby the vents. The Tudeep Sucker will remain at a safe distance from the vents, as it is not nearly as well adapted as the other organisms in the zone to survive the conditions, though its skin has become thicker, it lacks a hard outer shell to help it survive, which many other ridge organisms have. Its gills have moved forward and become smaller, round holes, as it's much less active lifestyle allows it to move much slower, therefore requiring less respiration. The holes have simple heat detection organs within them, allowing the Tudeep Sucker to steer away from water that is too warm for it to bear.
In response to this problem, it has developed a very unique strategy. This strategy involves using its enzymes to feed on the core of the Tudeep, however, unlike its ancestor, the Tudeep Sucker will continue to feed on the core until there is none left. It has evolved a more eel-like serpentine body and anguiliform locomotion to allow it to enter through the hole it makes in the outer shell, and its cartilaginous spines are smaller to allow access. Using the distinct blue bioluminescent lights to find their way, other Tudeep Suckers will arrive to feast on the core as well, often causing a large feeding and breeding frenzy. The carpotestans will then use the Tudeep's outer shell as a way to survive the extreme heat, as they will spend most of their time within the protective shell, only ever making holes in the opposite direction from the closest vent.
Groups of Tudeep Suckers will reside within the Tudeep shells for their entire lives, breeding and feeding on nearby Protohydroia colonies furthest from the vents, as well as on Hellworms, using their primitive tongue-like skin-flap to scoop them up. The flap can seal against the creature's mouth, allowing it to liquefy prey within its mouth-tube.