The various species that survive in the depths of the ocean are rarely more than 12 inches long.  Some live deeper than others and several swim to the surface at night.  Many have developed special adaptations to survive in this extreme environment.  The viperfish and lanternfish have light organs on their bodies to confuse their enemies.  Others such as the anglerfish and stomiatoid use luminous lures to attack prey.  Creatures of the twilight zone eat one another or survive on dead animals or algae that rain down from above.

 
 

Wolffish