n = 59
| Scientific Name | Author | Valid Name | Family | English Name |
|---|---|---|---|---|
| Gymnotus acus | Brünnich, 1768 | Carapus acus | Carapidae | Pearl fish |
| Gymnotus aequilabiatus | Humboldt, 1805 | Sternopygus aequilabiatus | Sternopygidae | |
| Gymnotus albifrons | Linnaeus, 1766 | Apteronotus albifrons | Apteronotidae | Black ghost |
| Gymnotus anguillaris | Hoedeman, 1962 | Gymnotus anguillaris | Gymnotidae | |
| Gymnotus arapaima | Albert & Crampton, 2001 | Gymnotus arapaima | Gymnotidae | |
| Gymnotus arapiuns | Kim, Crampton & Albert, 2020 | Genus Species | New species | |
| Gymnotus ardilai | Maldonado-Ocampo & Albert, 2004 | Gymnotus ardilai | Gymnotidae | |
| Gymnotus aripuana | Kim, Crampton & Albert, 2020 | Genus Species | New species | |
| Gymnotus asiaticus | Linnaeus, 1758 | Channa asiatica | Channidae | Small snakehead |
| Gymnotus bahianus | Campos-da-Paz & Costa, 1996 | Gymnotus bahianus | Gymnotidae | |
| Gymnotus brachiurus | Bloch, 1786 | Gymnotus carapo | Gymnotidae | Banded knifefish |
| Gymnotus capanema | Milhomem, Crampton, Pierczeka, Shetka, Silva & Nagamachi, 2012 | Gymnotus capanema | Gymnotidae | |
| Gymnotus capitimaculatus | Rangel-Pereira, 2014 | Gymnotus capitimaculatus | Gymnotidae | |
| Gymnotus carapo | Linnaeus, 1758 | Gymnotus carapo | Gymnotidae | Banded knifefish |
| Gymnotus cataniapo | Mago-Leccia, 1994 | Gymnotus cataniapo | Gymnotidae | |
| Gymnotus chaviro | Maxime & Albert, 2009 | Gymnotus chaviro | Gymnotidae | |
| Gymnotus chimarrao | Cognato, Richer-de-Forges, Albert & Crampton, 2008 | Gymnotus chimarrao | Gymnotidae | |
| Gymnotus choco | Albert, Crampton & Maldonado-Ocampo, 2003 | Gymnotus choco | Gymnotidae | |
| Gymnotus coatesi | La Monte, 1935 | Gymnotus coatesi | Gymnotidae | |
| Gymnotus coropinae | Hoedeman, 1962 | Gymnotus coropinae | Gymnotidae | |
| Gymnotus cuia | Craig, Malabarba, Crampton & Albert, 2018 | Gymnotus cuia | Gymnotidae | |
| Gymnotus curupira | Crampton, Thorsen & Albert, 2005 | Gymnotus curupira | Gymnotidae | |
| Gymnotus cylindricus | La Monte, 1935 | Gymnotus cylindricus | Gymnotidae | |
| Gymnotus darwini | Campos-da-Paz & de Santana, 2019 | Gymnotus darwini | Gymnotidae | |
| Gymnotus diamantinensis | Campos-da-Paz, 2002 | Gymnotus diamantinensis | Gymnotidae | |
| Gymnotus electricus | Linnaeus, 1766 | Electrophorus electricus | Gymnotidae | Electric eel |
| Gymnotus esmeraldas | Albert & Crampton, 2003 | Gymnotus esmeraldas | Gymnotidae | |
| Gymnotus eyra | Craig, Correa-Roldán, Ortega, Crampton & Albert, 2018 | Genus Species | New species | |
| Gymnotus henni | Albert, Crampton & Maldonado-Ocampo, 2003 | Gymnotus henni | Gymnotidae | |
| Gymnotus inaequilabiatus | (Valenciennes, 1839) | Gymnotus inaequilabiatus | Gymnotidae | |
| Gymnotus interruptus | Rangel-Pereira, 2012 | Gymnotus interruptus | Gymnotidae | |
| Gymnotus javari | Albert, Crampton & Hagedorn, 2003 | Gymnotus javari | Gymnotidae | |
| Gymnotus jonasi | Albert & Crampton, 2001 | Gymnotus jonasi | Gymnotidae | |
| Gymnotus longirostratus | Lacepède, 1800 | Rhamphichthys rostratus | Rhamphichthyidae | Trompet knifefish |
| Gymnotus macrurus | Bloch & Schneider, 1801 | Sternopygus macrurus | Sternopygidae | Longtail knifefish |
| Gymnotus maculosus | Albert & Miller, 1995 | Gymnotus maculosus | Gymnotidae | Spotted knifefish |
| Gymnotus mamiraua | Albert & Crampton, 2001 | Gymnotus mamiraua | Gymnotidae | |
| Gymnotus melanopleura | Albert & Crampton, 2001 | Gymnotus melanopleura | Gymnotidae | |
| Gymnotus notopterus | Pallas, 1769 | Notopterus notopterus | Notopteridae | Bronze featherback |
| Gymnotus obscurus | Crampton, Thorsen & Albert, 2005 | Gymnotus obscurus | Gymnotidae | |
| Gymnotus omarorum | Richer-de-Forges, Crampton & Albert, 2009 | Gymnotus omarorum | Gymnotidae | |
| Gymnotus onca | Albert & Crampton, 2001 | Gymnotus onca | Gymnotidae | |
| Gymnotus panamensis | Albert & Crampton, 2003 | Gymnotus panamensis | Gymnotidae | |
| Gymnotus pantanal | Fernandes, Albert, Daniel-Silva, Lopes, Crampton & Almeida-Toledo, 2005 | Gymnotus pantanal | Gymnotidae | |
| Gymnotus pantherinus | (Steindachner, 1908) | Gymnotus pantherinus | Gymnotidae | |
| Gymnotus paraguensis | Albert & Crampton, 2003 | Gymnotus paraguensis | Gymnotidae | |
| Gymnotus pedanopterus | Mago-Leccia, 1994 | Gymnotus pedanopterus | Gymnotidae | |
| Gymnotus putaol | Lacepède, 1800 | Gymnotus carapo | Gymnotidae | Banded knifefish |
| Gymnotus refugio | Giora & Malabarba, 2016 | Gymnotus refugio | Gymnotidae | |
| Gymnotus regius | Chiaje, 1847 | Electrophorus electricus | Gymnotidae | Electric eel |
| Gymnotus riberalta | Craig, Correa-Roldán, Ortega, Crampton & Albert, 2018 | Genus Species | New species | |
| Gymnotus rostratus | Linnaeus, 1766 | Rhamphichthys rostratus | Rhamphichthyidae | Trompet knifefish |
| Gymnotus stenoleucus | Mago-Leccia, 1994 | Gymnotus stenoleucus | Gymnotidae | |
| Gymnotus sylvius | Albert & Fernandes-Matioli, 1999 | Gymnotus sylvius | Gymnotidae | |
| Gymnotus tigre | Albert & Crampton, 2003 | Gymnotus tigre | Gymnotidae | |
| Gymnotus tiquie | Maxime, Lima & Albert, 2011 | Gymnotus tiquie | Gymnotidae | Tiquie banded knifefish |
| Gymnotus tremulus | Houttuyn, 1764 | Electrophorus electricus | Gymnotidae | Electric eel |
| Gymnotus ucamara | Crampton, Lovejoy & Albert, 2003 | Gymnotus ucamara | Gymnotidae | |
| Gymnotus varzea | Crampton, Thorsen & Albert, 2005 | Gymnotus varzea | Gymnotidae |