Freshwater Eels (Anguillidae)

Freshwater eel silhouette.

Freshwater eels have long, snake-shaped bodies. Scales are small and embedded in the skin, making them appear scaleless. Unlike lamprey, they have well-developed jaws. Freshwater eels have small gill openings and no spines or pelvic fins. Their dorsal, anal and tail fins are continuous.

There is only one species of freshwater eel in Connecticut. It is our state’s only catadromous fish, meaning that it lives most of its adult life in fresh water, but migrates to salt water to spawn. The European eel (Anguilla anguilla) is nearly identical in appearance and habits and spawns in the same general area of the Western Atlantic Ocean, but migrates to Europe and Northern Africa to complete its life cycle. The conger eel (Conger oceanicus), a strictly marine species, is similar in appearance, but has a longer dorsal fin originating close to the end of the pectoral fin and a projecting upper jaw.

Click on the species name below to learn more.

American Eel (Anguilla Rostrata) - Native

A 15-inch American eel.

Freshwater eels can be kept in home aquariums, but are problematic. Some individuals will accept pellets, others only live food, and some will refuse to eat. The American eel tends to hide under gravel during the day and can live a long time without food, so it may be difficult to tell whether it is eating. Also, eels are expert escape artists and will squeeze out of the smallest opening in an aquarium cover. Eels that are successfully acclimated to tank life will grow quickly and begin to harass/devour smaller tank mates.


Text and images adapted from Jacobs, R. P., O'Donnell, E. B., and Connecticut DEEP. (2009). A Pictorial Guide to Freshwater Fishes of Connecticut. Hartford, CT. Available for purchase at the DEEP Store.