Anguilla rostrata, known as the American eel, is a catadromous fish found in freshwater and coastal areas of North America. It exhibits a unique life cycle, migrating from freshwater habitats to the Sargasso Sea for breeding. The species is elongated, with a snake-like body and a distinctive ability to breathe through its skin, allowing it to traverse land in damp conditions.

Anguilla rostrata, commonly known as the American eel, is native to the western Atlantic Ocean. Its distribution extends from Greenland and Iceland in the north, down the eastern coast of North America, including the Gulf of Mexico and the Caribbean Sea, to as far south as Venezuela.

The American eel is a catadromous species, spending most of its life in freshwater or brackish environments such as rivers, streams, estuaries, and lakes. It migrates to the Sargasso Sea in the North Atlantic Ocean for spawning. Eels inhabit environments with a wide range of temperatures, typically preferring warmer waters but are adaptable to various conditions.

Anguilla rostrata occupies a unique ecological niche as both a predator and prey in aquatic ecosystems. In freshwater habitats, it preys on a variety of organisms, including insects, fish, and crustaceans. Its migratory behavior is crucial for life cycle completion, contributing to nutrient cycling between marine and freshwater ecosystems. The species' ability to traverse both freshwater and marine environments allows it to exploit diverse ecological niches.