[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Pisces
     Class Osteichthyes Huxley, 1880 - bony fishes and tetrapods see Clade Osteichthyes Huxley 1880 [Moore & Near 2020]
       Order Anguilliformes Berg, 1943 - eels
         Family Ophichthidae Günther, 1870 - snake eels and worm eels
           Genus Apterichtus Duméril, 1805
             1 Apterichtus anguiformis (Peters, 1877) - slender finless eel
             2 Apterichtus caecus (C. Linnaeus, 1758) - European finless eel