[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Enterozoa
     Grade Cœlomata
       Phylum Vertebrata (Lamarck, 1801)
         Branch Craniata Linnaeus, 1758
           Grade Gnathostoma
             Subgrade Heterodactyla branchiata
               Class Pisces Linnaeus, 1758 see Superclass Pisces Linnaeus, 1758
                 Subclass Teleostei Müller, 1845 see Infraclass Teleostei Müller, 1845
                   Branch Physostomi
                     Order Apodes Linnaeus, 1758 see Order Anguilliformes Rafinesque, 1810
                       Genus Gymnotus Linnaeus, 1758