European eels are fish with one pair of small pectoral fins and long, snake-like bodies.
As catadromous fish, European eels spend most of their adult lives in freshwater rivers, streams, and estuaries before returning to the open ocean to spawn and lay eggs. As young larvae, baby eels drift around the sea for between seven months and three years.
European eels go through several easily recognizable life stages on their journey to adulthood. As larvae, eels are known as leptocephalus because of their thin heads and wider bodies that give them a leaf-like shape, but as they age, the animals become longer and thinner. As their bodies become larger and more translucent, the fish become known as “glass eels.”