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American eel

Anguilla rostrata

Life HistoryAmerican eel

  • American eels have a catadromous life cycle, meaning they live most of their lives in fresh or brackish water and return to the sea to spawn.
  • The journey of the American eel begins soon after it is born in the Sargasso Sea in the Atlantic Ocean. The youngest eels, called leptocephali (meaning narrow head), are carried on ocean currents until they reach coastal waterways where they transform into glass eels and start swimming upstream.
  • Unlike salmon and other anadromous fish that leap waterfalls as mature adults to return to spawning grounds, eels navigate their way upstream as juveniles.
  • Juvenile eels (called elvers) overcome great obstacles such as waterfalls and rapids by traversing wet rocks and damp grass.
  • Once they reach their destination, older juveniles (called yellow eels) live in estuaries, rivers, and streams for 5 to 25 years before becoming sexually mature.
  • Once sexually mature, eels turn a silvery color and begin their long migration back to spawning grounds in the Sargasso Sea to start the cycle over again.


  • American eels were an important food source for early Americans including natives and European settlers.
  • Commercial harvest of eels peaked across the eastern seaboard in the late 1970's.
  • A status review of American eel population was completed in January of 2007. The status review committee concluded that the eel population has declined in some areas but is not in danger of extinction at this time.
  • Although the eel population did not warrant listing as threatened or endangered in 2007, it was noted that there has been a decline over the past 10 years in the number of eels in Lake Ontario and the Chesapeake Bay.


  • Research is being conducted to determine the timing of downstream eel migration in the Shenandoah River.
  • Methods for eel passage on the Susquehanna River are being investigated.
  • A number of eel passage ramps have been implemented on tributaries to the St. Lawrence Seaway, the Gulf of Maine, and the Shenandoah River in Virginia.
Last updated: February 18, 2016
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