Phylum Chordata Bateson, 1885 - chordates
   Subphylum Vertebrata Cuvier, 1812 - vertebrates
     Pisces
       Class Actinopterygii Woodward, 1891 - ray-finned fishes
         Order Acipenseriformes Berg, 1940 - sturgeons
         Order Albuliformes Greenwood et al., 1966 - bonefishes
         Order Amiiformes Hay, 1829 - bowfins
         Order Anguilliformes Rafinesque, 1810 - eels
         Order †Aspidorhynchiformes Bleeker, 1859
         Order Atheriniformes Rosen, 1964 - silversides
         Order Aulopiformes Rosen, 1973 - lizardfishes
         Order Batrachoidiformes Berg, 1937 - toadfishes
         Order Beloniformes Berg, 1937 - needlefishes
         Order Beryciformes Günther, 1880 - alfonso squirrelfishes
         Order Cetomimiformes see Superfamily Cetomimoidea
         Order Characiformes Goodrich, 1909 - characins
         Order Clupeiformes Rafinesque, 1810 - herrings
         Order Ctenothrissiformes Patterson, 1964
         Order Cypriniformes Rafinesque, 1810 - carps
         Order Cyprinodontiformes Berg, 1940 - killifishes
         Order †Dorypteriformes Cope, 1871
         Order †Ellimmichthyiformes Grande, 1982
         Order Elopiformes Gosline, 1960 - tenpounders
         Order Gadiformes Rafinesque, 1810 - cods
         Order Gasterosteiformes Gill, 1872 - sticklebacks
         Order Gobiesociformes Gill, 1872
         Order Gonorynchiformes Regan, 1909 - milkfishes
         Order Gymnotiformes Rafinesque, 1810 - American knifefishes
         Order †Haplolepidiformes
         Order †Ichthyodectiformes Bardack & Sprinkle, 1969
         Order Lampriformes - opahs see Order Lampridiformes Goodrich, 1909, orth. inval.
         Order Lepisosteiformes Hay, 1929 - gars
         Order †Leptolepidiformes
         Order Lophiiformes Rafinesque, 1810 - anglerfishes
         Order †Luganoiiformes Lehman, 1958
         Order †Macrosemiiformes
         Order Myctophiformes Regan, 1911 - lanternfishes
         Order Notacanthiformes Goodrich, 1909 - spiny eels
         Order Ophidiiformes Rafinesque, 1810 - cusk-eels
         Order Osteoglossiformes Berg, 1940 - bonytongues
         Order †Pachycormiformes Berg, 1940
         Order †Palaeonisciformes Jarvik, 1961
         Order †Pattersonichthyiformes
         Order †Peltopleuriformes
         Order Perciformes Rafinesque, 1810 - perches
         Order Percopsiformes Berg, 1937 - trout-perches
         Order †Perleidiformes Berg, 1937
         Order †Phanerorhynchiformes
         Order †Pholidophoriformes
         Order †Pholidopleuriformes
         Order Pleuronectiformes Bleeker, 1859 - flatfishes
         Order Polypteriformes - bichirs
         Order †Ptycholepiformes Andrews et al., 1967
         Order †Pycnodontiformes Berg, 1937
         Order †Redfieldiiformes Berg, 1940
         Order Saccopharyngiformes - sackpharynx fishes see Suborder Saccopharyngoidei
         Order Salmoniformes Rafinesque, 1810 - trouts
         Order †Saurichthyiformes Aldinger, 1937
         Order Scorpaeniformes Bloch, 1789 - mail-cheeked fishes
         Order †Semionotiformes Aramboug & Bertin, 1958
         Order Siluriformes Rafinesque, 1810 - catfishes
         Order Stomiiformes Rosen, 1973 - dragonfishes see Order Stomiatiformes Rosen, 1973, orth. inval.
         Order Synbranchiformes - swamp eels
         Order Syngnathiformes Berg, 1940 see Suborder Syngnathoidei
         Order †Tarrasiiformes
         Order Tetraodontiformes Berg, 1937 - plectognaths
         Order Zeiformes Rafinesque, 1810 - dories