Anguillidae - Eels

Description
The Anguillidae are a family of ray-finned fish that contains the freshwater eels. Eighteen of the 19 extant species and six subspecies in this family are in the genus Anguilla.
They are elongated fish with snake-like bodies, their long dorsal, caudal and anal fins forming a continuous fringe.
They are catadromous fish, spending their adult lives in freshwater, but migrating to the ocean to spawn.