Some of the better known electric fish are the South American electric eel Electrophorus electricus, and the African electric catfish Malopterurus electricus. Another famous electric fish is the Mediteranean electric ray Torpedo torpedo. There is also an electric catfish from China, the Parasilurus asota. These are large fish with powerful electric discharge organs. They use the electric discharge to stun their prey and deter predators.
Other electric fish are more like the elephant nose fish, where the electric discharge is very small, and used for navigation and communication.
In the same family of fish (called mormyriform fish) as the elephant nose are several other species, such as Pollimyrus isidori, Gymnarchus niloticus, and Brienomyrus brachyistius.
Another family of weakly electric fish are the South American gymnotoid fish, such as Hypopomus artedi, Sternopygus, and Eigenmannia. While Hypopomus produces pulses like the elephant nose fish, the others produce pure continuous sine waves.
The South American gymnotoid fish Eigenmannia virescens (the Glass Knifefish), Apteronotus leptorhynchus (the Brown Ghost Knife fish), and Apteronotus albifrons (the Black Ghost Knife fish) are easy to find in tropical fish stores. They are all of the continuous sine wave type, rather than the pulse type.