Eel Families
[order Anguilliformes families Anguillidae (freshwater), Congridae (saltwater), Muraenidae (Morays), others, and order Synbranchiformes (Swamp Eels)]

Anguilliforms is a large order of fish that have become very elongated to the point of resembling snakes and worms. While related to other modern ray-finned fish they tend to be rather primitive and a bit simplified. Freshwater eels spawn at sea and die there. Their offspring enter rivers as juveniles and live there until time to spawn. Lacking scales in most cases and scales that can be scraped off without tearing the skin in all cases, eels are not kosher..   Drawing of American Eel by Ellen Edmonson and Hugh Chrisp, copyright expired.

More on Varieties of Fish

American Eel - [Anguilla rostrata]

This freshwater eel is found in rivers and streams along the West Atlantic from Greenland to the tip of South America but is most common in the temperate zones of that range. Female eels can grow to 60 inches and 16 pounds but males only to 18 inches. North of the equator these eels go to the Saragaso Sea to spawn and die, a little to the west of where the European eels go. Aquaculture depends on capturing returning juveniles. There is a big market in Asia for these juveniles because of an eel shortfall there but populations are declining and protections are being considered by the U.S. Fish and Wildlife Service.   Illustration from U.S. National Oceanic and Atmospheric Administration = public domain.

European Eel - [Anguilla anguilla]

This freshwater eel is found in rivers and streams along the East Atlantic from Morocco to northern Norway and in the Mediterranean, Baltic and Black seas. These eels can grow to 52 inches and 14 pounds but market size is much smaller. These eels go to the Saragaso Sea to spawn and die, a little to the east of where the American eels go. Aquaculture depends on capturing returning juveniles but the runs have been scant recently and this eel is listed as CR "Critically Endangered". Do not catch or eat this eel.   Photo by Ron Offermans distributed under license Creative Commons Attribution-Share Alike 3.0.

Japanese Eel - [Unagi (sushi), Anguilla japonica]
This freshwater eel, native to Japan, China and Southeast Asia including the Philippines, is caught wild and farmed. japonica spawns far out to sea and then dies, so aquaculture depends on capturing returning juveniles. They can grow to nearly 60 inches but are generally marketed much smaller. This fish is highly prized and expensive in Japan and is not seen in California markets - in fact most farmed eels in Japan are now American eels because the supply of Japanese eels is approaching "none".

Conger Eels - [Anago (sushi), Conger conger (European), Conger myriaster (Japanese) and others of family Congridae]

This strictly ocean eel is much larger than the freshwater eels and much more robust in its reproduction habits. The European Conger can grow to nearly 10 feet and 350 pounds. They are found worldwide and there isn't a lot of difference from one species to another.   Illustration of Conger conger from U.S. National Oceanic and Atmospheric Administration = public domain.

Pike Conger - [Hamo (Japan); Daggertooth Pike Conger, Summer Eel; Ca Lat Cat Khuc (Viet); Muraenesox cinereus]

While this Indo-West Pacific eel can grow to 7 feet, it is commonly about 3 feet long. Though it is very expensive to prepare and bland in taste, hamo is very popular around Kyoto, Japan. In ancient times it was one of very few fish tough enough to survive a multi-day journey to the inland capital. It is shot full of bones and cannot be de-boned, so Kyoto sushi chefs use special techniques. The photo specimens, from Vietnam, were about 2 inches diameter by 2-1/2 inches high. This fish has no scales so is not kosher. Details and Cooking. .

Spiny Eel - Not actually an eel, see Spiny Eel

Swamp Eel - [Rice Eel, Asian Swamp Eel, Monopterus albus of family Synbranchidae]

This eel is native to Southeast Asia, China and Japan, and possibly Bangladesh (a very similar but smaller eel, M. cuchia is found from Pakistan through Bangladesh and Burma). M. albus can grow to a little over 39 inches but the photo specimen, bought from an Asian market in Los Angeles, was 32 inches and weighed 1.1 pound factory cleaned. This eel is in no way endangered and can be a pest. Feel free to eat as many as you'd like.   Details and Cooking.