Phylum Chordata Bateson, 1885 - chordates Subphylum Vertebrata Cuvier, 1812 - vertebrates Pisces Class Actinopterygii Woodward, 1891 - ray-finned fishes Order Gymnotiformes Rafinesque, 1810 - American knifefishes Family Gymnotidae Rafinesque, 1815 - nakedback knifefishes