The American eel (Anguilla rostrata) is a facultative catadromous eel found on the eastern coast of North America. Freshwater eels are fish belonging to the elopomorph superorder, a group of phylogenetically ancient teleosts. The American eel has a slender, supple, snake-like body that is covered with a mucus layer, which makes the eel appear to be naked and slimy despite the presence of minute scales. A long dorsal fin runs from the middle of the back and is continuous with a similar ventral fin. Pelvic fins are absent, and relatively small pectoral fins can be found near the midline, followed by the head and gill covers. Variations exist in coloration, from olive green, brown shading to greenish-yellow and light gray or white on the belly. Eels from clear water are often lighter than those from dark, tannic acid streams.
The American eel is the only species of freshwater eel found in North America. It once made up over a quarter of the total fish found in many Atlantic coastal streams. Indeed, the eel is a valuable food source for larger fish and fish-eating birds, as well as people. Eels are catadromous, meaning they primarily live in rivers and estuaries, but migrate out to the ocean - the Sargasso Sea, to spawn. American eels are an elongated fish, with fairly small fins. They use their whole body to swim in undulating motions. American eel is the only catadromous fish in North America, meaning it lives mostly in freshwater but returns to the ocean to spawn. Read on to learn more about this fish species.
