An elver is a juvenile eel that has completed its leptocephalus (larval) stage and is migrating upstream from the ocean into freshwater streams to develop further. Elvers are typically small, translucent, bottom-dwelling, and cylindrical, resembling clear tape when swimming. They are also the most valuable fish by weight in some areas, especially in the United States, and are harvested for consumption, aquaculture, and the European and American eel markets.