The Eurypharynx pelecanoides, commonly known as the gulper eel or pelican eel, is a deep-sea fish notable for its enormous mouth, which can inflate to swallow prey larger than itself. Found at depths of 500-3,000 meters, it has a long, whip-like tail and bioluminescent organs that help it attract food in the pitch-dark ocean depths.

Eurypharynx pelecanoides, commonly known as the gulper eel or pelican eel, is found in deep-sea environments of the Atlantic, Pacific, and Indian Oceans. Its geographical distribution is primarily in the mesopelagic to bathypelagic zones, typically at depths ranging from 500 to 3,000 meters (1,640 to 9,840 feet).

This species inhabits the deep ocean, characterized by high pressure, low temperatures, and complete darkness. The water temperature in these regions is usually near freezing, and the environment lacks sunlight, relying on bioluminescence for occasional illumination.

The gulper eel is adapted to the deep-sea environment with features such as an expandable jaw and stomach, allowing it to consume prey much larger than itself. It occupies a niche as a predator in the deep-sea food web, feeding primarily on small crustaceans, cephalopods, and other fish. Its large mouth and capacious stomach are adaptations to the scarce food resources available in its habitat.