What animal's young is called an "elver"?

The young of an eel is called an elver. This name refers to a juvenile eel after it has passed through its transparent glass-eel stage and begun moving toward its growing habitat.

Eels have an unusually complex life cycle. They begin as flat, leaf-shaped larvae called leptocephali, which drift through the ocean. After metamorphosing into glass eels, they develop pigmentation and become elvers. Freshwater eels may then travel far upstream, sometimes climbing around waterfalls, dams, and other barriers.

The word can cause confusion because “elver” does not mean an eel egg or the very earliest larva. It identifies a later juvenile stage. Mature freshwater eels eventually return to the ocean to reproduce, while many marine eel species remain in saltwater throughout their lives.

“Eel” also describes several unrelated eel-shaped animals. The electric eel, for example, is actually a South American knifefish rather than a true eel in the order Anguilliformes.