Anguilla eels are termed freshwater eels, although some species (including the American eel) are able to complete their entire life cycle in salt water. Freshwater eels (Anguilla spp.) are categorized as the order of Anguilliformes and have unique life cycle characters as a catadromous fish. Catadromous fish is a fish that migrate between freshwaters and sea waters. The fish spawn in the deep sea, produce larvae (leptocephalus) and are carried by turbulent current towards the edge of ocean.
There are three species of freshwater eel, the American eel (Anguilla rostrata), European eel (A. anguilla), and Japanese eel (A. japonica), but the American eel is the only species of freshwater eel found in North America.
The American eel, Anguilla rostrata lives in nearshore areas of lakes and streams with various bottom types, including rocks. American eel evolved more than 2 million years ago, when the ancestral Atlantic eel species gave rise to both the European and American species of eel. The American eel has survived multiple ice ages and seems to be equipped to withstand the cycles and fluctuations inherent in ocean dynamics.
The species of American eel has phenotypic plasticity that allows eels to adapt to a wide range of habitat types, from estuaries to freshwater headwater habitats. As a result of this plasticity, the species is widely distributed in accessible lakes, rivers, streams, and estuaries from eastern Canada to Venezuela.
The American eel is, in many ways, a typical anguillid in body shape and size and life cycle, and also in that people who encountered it and needed sustenance always found it to be excellent food.
While some American eels swim up freshwater streams to mature, others remain and mature in both estuarine and marine waters. Eels can absorb oxygen through their skin and gills, allowing them to travel over land, particularly wet grass or mud.
Various tribes clearly used eels as a food resource. Smoked eel was light in weight but nutritious, making it an important food for travelers. Indeed, it is likely that eel meat is more nutritious than that of most other fish, so it provided a valuable source of protein and helped people survive the long, cold winters.
Eels are still smoked and sold in some parts of the US, and eel is consumed in small quantities in Atlantic Canada.
The American Eel
