silver eel

The term "silver eel" refers to an eel that has reached sexual maturity and is preparing to return to the ocean to breed. Eels, of which there are over 500 species, are characterized by their slender, elongated bodies and continuous fins.1

Catadromous fish, like the eel genus Anguilla, spend most of their lives in freshwater before migrating to the sea to reproduce. European and North American eels, for example, spawn in the Sargasso Sea. Their transparent young, called leptocephali, drift on currents to continental shelves, where they transform into glass eels. These then migrate upstream into freshwater, growing into yellow eels over 10-15 years. Finally, they become silver eels, with larger eyes, and migrate back to the sea to spawn, after which they die.23