The name spiny eel is used to describe members of two different families of fish: the freshwater Mastacembelidae of Asia and Africa, and the marine (and generally deep sea) Notacanthidae. Both are so-named because of their eel-like shape and sturdy fin spines. These two families are not related and that the Notacanthiformes belong to the Superorder Elopimorpha, of which members are characterized by having a leptocephalus larvae. The freshwater Mastacembelids do not share this characteristic and are popular specimens in the aquarium trade. Mastacembelid Spiny eels originate from three places. The Middle East, Southeast Asia and Africa.