[4] Its retina is made up entirely of rods and no cones, with rhodopsin/porphyropsin pairs and a single opsin bound to some of its photoreceptors, which provide visual sensitivity up to 517-541 nm (this falls within the wavelength of red light).

[5] Most deep-sea fish have a single visual pigment maximally sensitive at short wavelengths, approximately matching the spectrum of both downwelling sunlight and bioluminescence.

The yellow lens reduce the amount of blue light that reaches the retina and increases sensitivity to longer wavelengths, which benefits M. niger and its red bioluminescence.

The anterior vertebrae appear to be unossified which enables the fish to “throw back its head” to take on relatively large prey.

[7] Lastly, M. nigers lacks an ethinoid membrane (no “floor” in its mouth) which allows for it to consume bigger prey species (Figure D).

This adaptation also minimizes the amount of energy required for M. niger to close its mouth, thus permitting it to quickly latch onto fast-swimming prey.

[9] While the morphology of M. niger with huge fangs and an enormous gape is typical for its family and suggests adaptations to piscivory, its diet in fact contains a substantial proportion of zooplankton.

Current research suggests that M. niger has adopted this unique feeding habit in association with the abundance of prey.

Recent studies in the eartern Gulf of Mexico indicate that large calanoid copepods are three orders of magnitude more abundant than either fish or shrimp.

[11][12] Malacosteus niger's unique adaptation of producing red bioluminescence is only found in two other deep-sea dwelling creatures, Aristostomias and Pachystomias.

[5] Other deep-sea fish capable of detecting far-red bioluminescence, including Aristostomias and Pachystomias are able to do so using visual pigments.

[14] Malacosteus Niger has a tear-drop shaped, dark brown, suborbital photophore which is used to emit red light at an emission maxima of 710 nanometers.