The American eel (Anguilla rostrata) is a facultative catadromous fish found on the eastern coast of North America. Eels (Anguilla spp.) are fish belonging to the elopomorph superorder, a group of phylogenetically ancient teleosts. The American eel has a slender snakelike body that is covered with a mucous 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 fin 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 f