Biology The American eel, as well as the European eel, spawns during the winter in the Sargasso Sea, a tropical area northeast of Cuba. Adult eels spend most of their lives in freshwater, although he amount of time may vary among individuals. At some point, however, adults leave their freshwater habitats and move toward the Sargasso Sea. Neither adults or eggs have been collected in the vicinity of the Sargasso Sea, but newly hatched eels are found there. Presumably, spawning takes place in deep water and the adults die shortly thereafter.
Young eels are transparent and leaf shaped.
Years ago when they were first collected they were thought to be a new fish species and erroneously give the scientific name Leptocephalus. By the time American eels get close to the coast they are about 6 inches in length. The species only begins to develop coloration when the young reach nearshore areas. Once they reach freshwater, females continue to migrate deep inland as far up rivers and tributaries as they can. Males remain much closer to coastline areas.