Silver eels are the mature stage of the European eel (Anguilla anguilla) and American eel (Anguilla rostrata). They are named for their silvery coloration, which develops as they prepare to migrate from freshwater or coastal habitats to the Sargasso Sea for spawning. This transformation includes changes in body shape and eye size, allowing them to travel long distances. These eels can live for many years, often over a decade, before they begin their migration. During this time, they feed on various prey, including insects, crustaceans, and small fish. The journey to the Sargasso Sea is a remarkable feat, as they can travel thousands of miles.