The Abyssopelagic Zone, also known as the Abyssal Zone, is a very dark place in the 2003 Disney/Pixar animated film Finding Nemo. As its name suggests, the Abyssopelagic Zone is a very deep part of the ocean where Philip Sherman's mask sinks into and in which Marlin and Dory encounter a very territorial deep sea anglerfish while trying to find the mask.
While Marlin and Dory attempt to retrieve Philip Sherman's mask which fell into the abyssal zone, they suddenly swim through a small luminescence of light after being attracted to it. As soon as Dory touches the light and Marlin and Dory follow the light, behind them is a territorial anglerfish which shows its bioluminescence and roars at the two fish when it entices the two with its glowing dorsal fin before chasing them as the two fish try to search for Phillip Sherman's diving mask which sank into the bottom of the ocean. After Dory says that she cannot see a thing, the anglerfish suddenly sees the spot where Dory and Marlin are at behind the mask that Philip Sherman lost in which Marlin tells Dory to read what it says on the mask while the anglerfish is chasing him. After Dory reads the words on Philip Sherman's mask, the anglerfish eventually gets caught in the mask around a rock, immobilizing it, but not before attempting one last bite at Marlin and Dory. The two fish manage to leave from the dark abyssal zone after defeating the anglerfish as they head off to continue their journey to find Nemo.
The location is seen again in the post-credits scene where Blenny, the small green fish, notices the anglerfish behind him in which Blenny suddenly eats it in one bite.