Anguille commune (Anguilla anguilla) nageant dans la Nivelle (Pyrénées-Atlantiques (64), Aquitaine, France). / A river eel (Anguilla anguilla) swimming in the Nivelle river (Pyrenees Atlantiques - Aquitaine - France). Also known as European eel, Common eel, that migratory fish has to cross the Atlantic Ocean in order to breed in the Sargasso Sea.