|Black ghost knifefish, Apteronotus albifrons|
The Gymnotiformes is a lineage of electric fishes. Common names include the Neotropical electric fishes, South American electric fishes, or American knifefishes. They are primarily freshwater inhabitants. They have organs adapted to the generation of electric fields.
Perhaps the best-known species is the electric eel (Electrophorus electricus) which uses powerful electric shocks (up to 600 V) for hunting and self-defense. Other species familiar in the aquarium trade are: the black ghost knifefish (Apteronotus albifrons), the glass knifefish (Eigenmannia virescens), and the banded knifefish Gymnotus carapo.