Fish and Aquatic Conservation


 artwork of an American eel

Fish illustration by Laury Zicari, USFWS, Retired

American eel

My Scientific Name

Anguilla rostrata

By the Numbers

If I am a female, I can grow up to 4 feet in length and weigh up to 9 pounds. Males only reach 1.5 feet in length. Females also are lighter in color, with smaller eyes and higher fins than males.

How to Identify Me

When I am an adult my coloring is olive-green or brown on my back and pale green or yellow on my sides and underneath. I have long dorsal and anal fins that are joined to my tail fin with two small pectoral fins behind my gills.

Why I Matter and What's Been Happening

My species once made up over a quarter of the total fish found in Atlantic coastal streams. Dams have prevented us from reaching our feeding grounds, and have reduced the amount of good habitat for us to live in the river. And when we migrate downstream to return to the ocean, we can get caught, and sometimes even die, in turbines at hydroelectric facilities, where electricity is generated using river water.

My Status

Biologists are studying my downstream migration to see if large dams that are used to generate electricity are having an effect on my journey. The biologists are also working on ways to safely move us up and downstream of dams.


did you know image
  • American eels are the only species of freshwater eel found in North America.
  • They live along the Atlantic coastline from Venezuela to Greenland and Iceland. Eels can also be found in the Great Lakes and Mississippi River (Figure 1).
  • Eels have a complex lifecycle that begins far offshore in the Sargasso Sea where adults spawn.
  • After eggs hatch, young eels drift inland with ocean currents into streams, rivers and lakes for over 3,700 miles. This journey may take many years.
  • Young eels stay in freshwater until they reach maturity, between 10 to 25 years, before migrating back to the Sargasso Sea.
  • Eels hunt at night, feeding on crustaceans, small insects and other fish.
  • During the day, they hide among tree snags, plants, and other types of shelters found close to shore.

Placeholder image

Figure 1 – Where American eel are found.



an eel lying down on a bi-fold wooden board

Ever heard the phrase slippery as an eel? Eels can cover their bodies with a mucous layer, making them nearly impossible to capture by hand.


Countless eels on a wooden step of fishway ramps

Biologists study upstream migration of juvenile eels, or elvers, that are using specially designed ramps to migrate around a dam.


How you can help statement: Get to know me, if you don’t already. Help make me visible to people who don’t have the chance to see me by sharing your stories about me. Get involved in efforts to help conserve my habitat and maintain my populations into the future.