The American Eel River (Anguilla rostrata) has a long, slender snake-like body. It is covered with a mucous layer so it looks naked and slimy but it is actually covered with tiny scales. It has a long dorsal fin down the middle of its back and a similar ventral fin.
American Eels have a very interesting life history. They live in fresh water but leave to make the spawning migration to the Sargasso Sea! A female eel might live in freshwater for 10-25 years but then she migrates to the ocean to spawn, lays up to 4 million eggs and dies. The little hatchlings, called leptocephalli, are flat and transparent, they metamorphosize into glass eels next. It takes them years to get from the ocean to fresh water, where they became yellow eels and eventually reach adult form.
They are bottom dwellers, hunting at night for crustaceans, aquatic insects, and whatever aquatic organisms they can find and hiding during the day in mud, sand and gravel close to the shore.

They are found all along the St. Lawrence and related river systems where they were once abundant and were an important fishery for aboriginal people. However the construction of hydroelectric dams has blocked their migration and reduced their numbers dramatically. According to the Ottawa Riverkeeper 98% of the eel population has collapsed in the Ottawa River. The construction of eel ladders enables migrating eels to get past obstacles. There is one at the Chaudiere Dam in the Ottawa River and it hoped that there will eventually be more at other dams.