American Eel (Anguilla rostrata)
Color: Greenish brown above, fading to yellowish
Size: Up to 4 feet long, females are larger than males.
Habitat: Muddy bottoms of freshwater rivers, tidal creeks, harbors, salt ponds.
Seasonal appearance: Spring to fall, buries in mud during winter months.
American eels are long, slender snakelike fish common in salt and fresh water along the Atlantic coast. Its body is rounded, with a long jaw and pointed snout. In front of its small, rounded eyes are two nostrils. The dorsal, caudal, and tail fins are joined and continuous from the middle of the back, around the tail, to the middle of the belly. It has no pelvic fins, and its scales are small in size and hardly noticeable. Often misidentified as sea snakes, American eels can be distinguished by the continuous fin that is absent in snakes.
Life History and Behavior
The American eel is a catadromous fish, exhibiting behavior opposite that of the anadromous river herring and Atlantic salmon. American eels migrate from fresh water to spawn in salt water. The early life history of the American eel has been discovered only recently. Adult eels, ages five to 35, migrate from freshwater creeks and rivers to spawn in the warm, nutrient-rich waters of the Sargasso Sea. The Sargasso Sea is located in the Caribbean east of the Bahamas and north of the West Indies. Adults die after spawning, and the larvae spend the next year drifting and swimming with the Gulf Stream then move east into northern coastal waters. American eel larvae do not resemble adults at hatching; instead, they are leaf-shaped, long, transparent, and flattened sideways. After the "leptocephalus" or larval stage, American eels transform into juveniles (elvers) resembling small adults. This process usually occurs during the journey to fresh water. Most elvers migrate toward freshwater streams and rivers, while some remain in the muddy waters of tidal creeks and marshes. Females migrate farther into fresh water than males, and American eels are nocturnal scavengers, preferring the night environment to forage for food.
Adapted from The Uncommon Guide to Common Life on Narragansett Bay. Save The Bay, 1998.