Gymnotus is a genus of Neotropical freshwater fish in the family Gymnotidae found widely in South America, Central America and southern Mexico (36th parallel south to 18th parallel north).

[5] Although not commonly eaten by humans, some members of this genus are used locally as fishing bait,[6] and occasionally kept in aquariums.

[7] Gymnotus occur in most freshwater habitats within their geographic range, with the exception of large and deep river channels, and can tolerate little oxygen (survives by breathing air directly from the water surface) and areas affected by pollution,.

[4] One species, G. curupira can survive in moist leaf litter if their aquatic habitat dries out.

[5][9] Like other Neotropical knifefish, they often lose their tail due to attacks by predators or aggressive encounters with conspecifics, but they are able to regenerate it.