Longtail knifefish
- kingdom: Animalia
- phylum: Chordata
- class: Actinopterygii
- order: Gymnotiformes
- family: Sternopygidae
- genus: Sternopygus
- species: Sternopygus macrurus
Penedo
AlagoasTefé
AmazonasCorumbá
Mato Grosso do SulBuritizeiro
Pirapora
Minas GeraisPetrolina
PernambucoCampos
Rio de JaneiroMogi das Cruzes
São Paulo
BrazilLeticia
AmazonasCalamar
MagdalenaCumaral
Villavicencio
Meta
ColombiaEloy Alfaro
Guayas
EcuadorGeorgetown
Demerara-MahaicaLinden
Upper Demerara-Berbice
GuyanaPuerto Ayacucho
AmazonasBruzual
San Fernando Apure
ApureCamaguán
Guárico
Venezuela