The Nyxoth Nautstar has moved deeper into the abyssal zone and grown substantially. Reaching a top size of 16 cm, it dwarfs its relatives in the waters above.
The larger depth requires adaptations for higher pressure; where this was most needed was in the shell. Under the extreme pressures of the abyss, most shells would crack without some form of reinforcement. This reinforcement is achieved through the development of internal struts to resist the compressive forces of the water. This web of struts is surrounded by body tissue but cannot house organs due to its layout within the body. These tissues thus adapted to provide a new function: neutral buoyancy. The tissue surrounding the shell struts is mainly composed of chambers filled with an organic oil. This oil is resistant to high pressures and also lighter than water, providing both a boost to the pressure adaptations of the shell and a feature to assist in the Nyxoth Nautstar's mobility.