It lives on the surface of wood sunken to abyssal depths.

On its dorsal (abactinal surface) it has many projecting abactinal spines whose morphology is distinct from the adambulacral spines.

Xyloplax janetae is a bathyal abyssal species, meaning it is found in the deepest part of the open ocean.

It has only been found clinging to sunken wood.

Xyloplax janetae is found clinging to sunken wood, where it feeds on the bacteria which decay the wood.