- Fishes of Minnesota
Profile - Fishes of Wisconsin
Profile - University of Michigan Museum of Zoology
The American eel is a catadromous fish; it lives most
of its life in freshwater and migrates to the ocean to spawn. The American eels of the Great Lakes and St. Lawrence spawn in the Sargasso sea, each female laying 10-20 million eggs. Juveniles drift north nearly 6000 km to the mouth of the St. Lawrence where they tranform to transparent glass eels (elvers). The juveniles that swim upstream hit the eel ladder on the Moses-Saunders dam when they are four to six years old. Scientists recently discovered that the Great Lakes basin contains only the female eels. At the mouth of the St. Lawrence, the female-to-male ratio is one-to-one but as you move upstream the population becomes dominated by females. The female eels remain in freshwater for 10 to 20 years, growing to as much as one metre in length and developing a yellow pigmentation that earns them the name golden eels. As summer fades, these eels leave the inland areas -- travelling under the darkness of night -- to return to the Sargasso Sea to spawn. During the long voyage, they metamorphose into sexually mature silver eels.
not migrating, female American eels live in medium to large streams
and lakes with muddy bottoms and quiet waters. They are most active at night, during
the day they are found hiding in the mud or under objects at the
bottom of the lake or river. American eels are exclusively meat eaters.
They feed on almost anything they encounter, live or dead, including
fish, frogs, crayfish, insects, snails, earthworms and larval lampreys.
American eel females grow larger than the males. Females recorded
as big as 150 cm (5 ft) and 2.3-3.2 kg (5-7 lbs); males generally
reaches a length of no more than 50 cm (1.5 ft).
The Great Lakes population of American eels has declined more than 90% over the last 50 years and is considered a species of concern.