Connecticut River Coordinator's Office
Northeast Region
Painting of an American eel - Credit:  U.S. Fish and Wildlife Service / Duane Raver
Painting of an American eel. Credit: Duane Raver/USFWS

This link opens in a new windowDownload a Fact Sheet (107 KB Adobe pdf file)

You will need Adobe Acrobat Reader software to open the document above. If you do not have this software, you may obtain it free of charge by following this link.


The American eel (Anguilla rostrata) has a long, cylindrical body, giving it a snakelike appearance. Eels have a thick, slimy skin colored olive to brown above, yellowish on the sides, and lighter below. Sometimes confused with the sea lamprey, it can be distinguished by its true jaw (the lamprey has a jawless sucking disk) and the single continuous fin running from the dorsal side to the pelvic area. Females average 24 to 36 inches, while the males are somewhat smaller.

Life History

The American eel is the only catadromous fish in the Connecticut River basin, maturing in fresh or brackish water and then returning to the sea to spawn. Spawning occurs in autumn in the Sargasso Sea with each female releasing upwards of fifteen million eggs. These eggs hatch into ribbon-like larvae, "leptocephali", that are carried to the coasts by Gulf Stream currents. During this ocean phase, they undergo metamorphosis, becoming cylindrical in shape. The two-inch young eels, known as "elvers," migrate to rivers on the Gulf and Atlantic coasts, where the males remain in brackish water. The females migrate further upstream, preferring deeper water in lakes, rivers, and streams. Here they remain for four to ten years, spending their days buried in the substrate and feeding at night on a variety of invertebrates and fish. At sexual maturity, the eels return to the ocean, spawn, and die.


American eels range from Greenland to South America, occurring in all major streams along the coastline. The females migrate far inland, and have been documented in nearly all states east of the Rocky Mountains. This is possible because eels are able to live out of water for short periods of time. Their ability to slither up a moist slope allows them to circumnavigate major obstructions (e.g. dams and waterfalls) along their routes. In the Connecticut River, they are ubiquitous in Connecticut and Massachusetts being found in nearly all water bodies. Eels are common to infrequent in southern Vermont and New Hampshire, and uncommon in the northern part of the watershed.


The American eel population has been declining in recent years. This is the result of several factors, notably dam construction and harvesting. Movement around major barriers causes the fish greater stress and may increase its susceptibility to predation. The eel is also being increasingly harvested for food. The young elvers can fetch a world market price of up to $600 per pound.

Restoration Efforts

American eel management activities include construction of eelpasses (for enabling upstream juvenile eel movement around dams) and enumeration of immigrating eels.

Return to top


Last updated: September 8, 2010
Connecticut River Coordinator's Office
Northeast Fisheries Resources Home
Northeast Region Home

U.S. Fish and Wildlife Service Home Page | Department of the Interior  |  | About the U.S. Fish and Wildlife Service  | Accessibility  | Privacy  | Notices  | Disclaimer  | FOIA