The mature European eel migrates 3,000 to 4,000 mi (4,828–6,437 km) to its spawning ground in the deep sea SW of Bermuda, a journey lasting several months; they use ocean currents to help them swim there, where they reproduce and then die. The young hatch as transparent ribbonlike larvae (called glass eels) that drift north and east on ocean currents for three years before entering a river; they then develop into elvers, tiny versions of the adult eel. The American eel follows the same pattern, except that the young require only one year to reach freshwater.
Once in freshwater, the developing elvers feed voraciously on dead and living animals, even traveling over short stretches of land in search of frogs and lizards. They hunt at night and rest by day. The male, which attains a length of 2 ft (61 cm), remains at the river's mouth, while the female (4 ft/122 cm) swims upstream, staying there from 5 to 20 years. When the eels are sexually mature their enormous appetite wanes, and they do not eat during migration to the spawning ground. Their oily flesh is regarded by some as a delicacy; the skin was formerly used as leather.
Eels are classified in the phylum Chordata , subphylum Vertebrata, class Actinopterygii, order Anguilliformes.
See studies by R. Schweld (2002) and J. Prosek (2010).
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
See more Encyclopedia articles on: Vertebrate Zoology