[2] The skin of Xenodermichthys possess an unusual system of compartmented sub-dermal spaces filled with a dilute fluid (possibly lymph), thought to serve as a buoyancy aid, alongside scale loss and poor skeleton calcification.

The photophores of Xenodermichthys have a distinctive reddish-violet hue in fresh specimens under white light, and are underlain with a greenish-blue reflector that lacks guanine.

[3] The eyes, which are large and well developed, contain visual pigments indicative of maximum sensitivity in deep blue light (~480nm), as is common in mesopelagic fishes.

[4] Xenodermichthys copei is a predator that feeds on pelagic organisms, with a diet primarily composed of planktonic and micronektonic crustaceans, including natant decapod prawns, calanoid copepods, and both gammarid and hyperiid amphipods.

[12] Xenodermichthys copei is host to a number of endoparasites, including trematodes (Paraccacladium jamiesoni,[13] Steringophorus blackeri,[14] Dinosoma ventrovesiculare[15], and Helicometra sp.