Abyssocottidae Berg, 1907 (taxonomy source)
Acanthoclinidae Günther, 1861 accepted as Acanthoclininae Günther, 1861 (taxonomy source)
Acanthoclininae Günther, 1861 (taxonomy source)
Acanthuridae Bonaparte, 1835 (taxonomy source)
Acanthuroidei accepted as Acanthuriformes (taxonomy source)
Acestrorhamphinae Eigenmann, 1907 (taxonomy source)
Acestrorhynchidae Eigenmann, 1912 (taxonomy source)
Acestrorhynchinae Eigenmann, 1912 (taxonomy source)
Acheilognathinae Bleeker, 1863 (taxonomy source)
Achiridae Rafinesque, 1815 (taxonomy source)
Achiropsettidae Heemstra, 1990 (taxonomy source)
Acipenseridae Bonaparte, 1831 (taxonomy source)
Acipenseriformes (taxonomy source)
Acropomatidae Gill, 1893 (taxonomy source)
Actinopteri (basis of record)
Adrianichthyidae Weber, 1913 (taxonomy source)
Adrianichthyinae Weber, 1913 (taxonomy source)
Agoniatinae Bleeker, 1859 (taxonomy source)
Agonidae Swainson, 1839 (taxonomy source)
Agoninae Swainson, 1839 (taxonomy source)
Akysidae Gill, 1861 (taxonomy source)
Alabetidae Gill, 1906 accepted as Cheilobranchinae Günther, 1870 (taxonomy source)
Albulidae Bleeker, 1849 (taxonomy source)
Albuliformes (taxonomy source)
Albulinae Bleeker, 1849 (taxonomy source)
Alburninae Girard, 1858 (taxonomy source)
Alepisauridae Swainson, 1839 (taxonomy source)
Alepocephalidae Bonaparte, 1846 (taxonomy source)
Alestidae Cockerell, 1910 (taxonomy source)
Alestiidae accepted as Alestidae Cockerell, 1910 (taxonomy source)
Alopiidae Bonaparte, 1835 (taxonomy source)
Amarsipidae Haedrich, 1969 (taxonomy source)
Ambassidae Klunzinger, 1870 (taxonomy source)
Amblycipitidae Day, 1873 (taxonomy source)
Amblyopinae Günther, 1861 (taxonomy source)
Amblyopsidae Bonaparte, 1845 (taxonomy source)
Amiidae Bonaparte, 1831 (taxonomy source)
Amiiformes (taxonomy source)
Ammodytidae Bonaparte, 1835 (taxonomy source)
Amphiliidae Regan, 1911 (taxonomy source)
Amphiliinae Regan, 1911 (taxonomy source)
Anabantidae Bonaparte, 1831 (taxonomy source)
Anabantoidei accepted as Anabantiformes (taxonomy source)
Anablepidae Bonaparte, 1831 (taxonomy source)
Anablepinae Bonaparte, 1831 (taxonomy source)
Anacanthobatidae von Bonde & Swart, 1923 (taxonomy source)
Anarhichadidae Bonaparte, 1835 (taxonomy source)
Anchariidae Glaw & Vences, 1994 (taxonomy source)
Ancistrinae Kner, 1854 (taxonomy source)
Anguillidae Rafinesque, 1810 (taxonomy source)
Anguilliformes (taxonomy source)
Anisochrominae Smith, 1954 (taxonomy source)
Anomalopidae Gill, 1889 (taxonomy source)
Anoplagoninae Gill, 1861 (taxonomy source)
Anoplogastridae Gill, 1893 (taxonomy source)
Anoplopomatidae Jordan & Gilbert, 1883 (taxonomy source)
Anoplopomatoidei accepted as Anoplopomatidae Jordan & Gilbert, 1883 (taxonomy source)
Anostomidae Günther, 1864 (taxonomy source)
Anotopteridae Zugmayer, 1911 (taxonomy source)
Antennariidae Jarocki, 1822 (taxonomy source)
Anthiinae Poey, 1861 accepted as Anthiadinae Poey, 1861 (taxonomy source)
Aphanopodinae Gill, 1863 (taxonomy source)
Aphredoderidae Bonaparte, 1845 (taxonomy source)
Aphyocharacinae Eigenmann, 1909 (taxonomy source)
Aphyoditeinae Géry, 1972 (taxonomy source)
Aphyonidae Jordan & Evermann, 1898 (taxonomy source)
Apistidae Gill, 1859 (taxonomy source)
Aploactinidae Jordan & Starks, 1904 (taxonomy source)
Aplocheilichthyinae Myers, 1928 (taxonomy source)
Aplocheilidae Bleeker, 1859 (taxonomy source)
Aplochitoninae Günther, 1864 (taxonomy source)
Aplodactylidae Günther, 1859 (taxonomy source)
Apogonidae Günther, 1859 (taxonomy source)
Apogoninae Günther, 1859 (taxonomy source)
Apsilinae Johnson, 1980 accepted as Lutjanidae Gill, 1861 (source of synonymy)
Apteronotidae Jordan, 1923 (taxonomy source)
Aptocyclinae Ueno, 1970 accepted as Cyclopteridae Bonaparte, 1831 (source of synonymy)
Aracanidae Hollard, 1860 (taxonomy source)
Aracaninae accepted as Aracanidae Hollard, 1860 (source of synonymy)
Arapaimidae Bonaparte, 1846 (taxonomy source)
Argentinidae Bonaparte, 1846 (taxonomy source)
Arhynchobatidae Fowler, 1934 (taxonomy source)
Ariidae Bleeker, 1858 (taxonomy source)
Ariinae Bleeker, 1858 (taxonomy source)
Ariommatidae Haedrich, 1967 (taxonomy source)
Arripidae Gill, 1893 (taxonomy source)
Artedidraconidae Andriashev, 1967 (taxonomy source)
Aspredinidae Adams, 1854 (taxonomy source)
Astroblepidae Bleeker, 1862 (taxonomy source)
Astronesthinae Günther, 1864 (taxonomy source)
Ateleopodidae Bonaparte, 1850 (taxonomy source)
Ateleopodiformes (taxonomy source)
Atherinidae Risso, 1827 (taxonomy source)
Atheriniformes (taxonomy source)
Atherininae Risso, 1827 (taxonomy source)
Atherinomorinae Dyer & Chernoff, 1996 (taxonomy source)
Atherinopsidae Fitzinger, 1873 (taxonomy source)
Atherinopsinae Fitzinger, 1873 (taxonomy source)
Atherioninae Schultz, 1948 accepted as Atherinomorinae Dyer & Chernoff, 1996 (source of synonymy)
Auchenipteridae Bleeker, 1862 (taxonomy source)