living organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Eukaryotae see Domain Eukaryota Chatton, 1925
     Kingdom Animalia Linnaeus, 1758 - animals
       Subkingdom Eumetazoa Butschli, 1910 see [unranked] Eumetazoa Bütschli, 1910
         Phylum Chordata Bateson, 1885 - chordates
           Subphylum Vertebrata Cuvier, 1812 - vertebrates
             Class Osteichthyes Huxley, 1880 - bony fishes see [unranked] Euteleostomi
               Subclass Actinopterygii Woodward, 1891 - ray-finned fishes see Class Actinopterygii Woodward, 1891
                 Order Cypriniformes Rafinesque, 1810 - carps
                   Suborder Characoidei
                     Family Gymnotidae Rafinesque, 1815 - nakedback knifefishes
                       1.1 Genus Apteronotus Lacépède, 1800
                       1.2 Genus Sternarchus Schneider, 1801
                       2 Genus Gymnotus Linnaeus, 1758
                       3.1 Genus Eigenmannia Jordan & Evermann, 1896
                       3.2 Genus Hypopomus Gill, 1864
                       3.3 Genus Rhamphichthys Müller & Troschel, 1848
                       3.4 Genus Sternopygus Müller & Troschel, 1848