Fish and Aquatic Conservation

illustration of an American eel

American eel

Anguilla rostrata (Lesueur, 1817)

Cool Facts

For many years the American eel was considered the only catadromous species in North America. Recently it has been determined that while some American eels swim up freshwater streams to mature, some other populations remain and mature in both estuarine and marine waters. Biologists now describe this dual strategy as facultative catadromy. The maximum recorded age for an American eel is 43 years. In Asia and Europe, eel is considered a delicacy. Most of the eels harvested along the Atlantic coast are exported overseas.

SIZE: Common length of the American eel is 50 cm (19.7 inches) with the maximum recorded length being 152 cm (59.8 inches). The maximum published weight for an American eel is 7.3 kg (16.6 lbs.)

RANGE: American eel are distributed between the Northwestern and Central Atlantic Ocean. They range from the island of Greenland southward along the Atlantic coast of Canada and the United States. American eel range even further south into Panama and throughout much of the West Indies and Trinidad.

HABITAT: American eels are born in the Sargasso Sea. Eel embryos hatch in approximately 19 days in water approximately 59 degrees Fahrenheit (15 degrees Celsius). Young eels are then carried on ocean currents until they reach the coastline where they transform into “glass eels” and begin swimming upstream. As they move upstream, glass eels transform again into “elvers.” Upon reaching their fresh water destination, the elvers transform one more time into “yellow eels.” American eels reach sexual maturity in approximately 5 to 25 years.

DIET: Adults usually feed at night on worms, small fish, crustaceans, clams and other mollusks.

Natural History

The American eel inhabits marine, estuarine and fresh water habitats just like many other diadromous species. However, the America eel is not an anadromous species of fish. The American eel has a life history strategy that is different from all of the other diadromous species in North America. The American eel is catadromous. The American eel lives in fresh or brackish water during as an adult and then migrates into the ocean to spawn. American eel adults die after spawning.


American eel inhabiting the eastern Atlantic coast of the United States are managed by the Atlantic States Marine Fisheries Commission with the Atlantic Coast Fishery Management Plan for American Eel. A status review of the Atlantic coast American eel populations was completed in January 2007 and 2015. Results of both of these reviews determined that Atlantic coast American eel populations did not warrant a listing as threatened or endangered.

The Great Lakes Fishery Commission also acknowledges the precarious state of American eel populations in the Great Lakes. The American eel faces multiple threats because they are harvested at various stages of their life cycle for aquaculture, bait, and food. The long migration pattern of the American eel have forced multiple fishery management jurisdictions such as the United States, Canada, and tribes to all work together to conserve and restore American eel stocks.

Migration Behavior

The American eel is a migratory species. Unlike many other migratory species, The American eel spends its adult life in fresh water and then migrates down to the Sargasso Sea(salt water) to reproduce. These fish migrate up and down the Atlantic coast of the U.S.