• “Montereina” concinna (Alder & Hancock, 1864) represented as Discodoris concinna (Alder & Hancock, 1864)
• Abalistes stellatus (Anonymous, 1798)
• Abantennarius dorehensis (Bleeker, 1859)
• Abantennarius nummifer (Cuvier, 1817)
• Abarenicola pacifica Healy & Wells, 1959
• Abathescalpellum fissum (Hoek, 1907)
• Abathescalpellum koreanum (Hiro, 1933)
• Abdopus aculeatus (A. d'Orbigny, 1834)
• Abelbolla boucheri Huang & Zhang, 2004
• Abelbolla huanghaiensis Huang & Zhang, 2004
• Abelbolla warwicki Huang & Zhang, 2004
• Ablabys macracanthus (Bleeker, 1852)
• Ablabys taenianotus (Cuvier, 1829)
• Ablennes hians (Valenciennes, 1846)
• Abra fujitai T. Habe, 1958
• Abra inanis Prashad, 1932
• Abra kinoshitai (Kuroda & T. Habe, 1958)
• Abra kurodai T. Habe, 1961 accepted as Abra fujitai T. Habe, 1958
• Abra lunella (A. Gould, 1861)
• Abra maxima (G. B. Sowerby III, 1894) accepted as Abra philippinensis (E. A. Smith, 1885)
• Abra philippinensis (E. A. Smith, 1885)
• Abra profundorum (E. A. Smith, 1885)
• Abra profundorum japonicum Okutani, 1975 accepted as Abra profundorum (E. A. Smith, 1885)
• Abra sibogai Prashad, 1932
• Abralia (Abralia) multihamata Sasaki, 1929 represented as Abralia multihamata Sasaki, 1929
• Abralia (Heterabralia) andamanica E. S. Goodrich, 1896 represented as Abralia andamanica E. S. Goodrich, 1896
• Abralia andamanica E. S. Goodrich, 1896
• Abralia multihamata Sasaki, 1929
• Abraliopsis (Micrabralia) lineata (E. S. Goodrich, 1896) represented as Abraliopsis lineata (E. S. Goodrich, 1896)
• Abraliopsis lineata (E. S. Goodrich, 1896)
• Abrina inanis (Prashad, 1932) accepted as Abra inanis Prashad, 1932
• Abrina lunella (A. Gould, 1861) accepted as Abra lunella (A. Gould, 1861)
• Abrina sibogai (Prashad, 1932) accepted as Abra sibogai Prashad, 1932
• Abrina skinoshitai [sic] accepted as Abra kinoshitai (Kuroda & T. Habe, 1958)
• Abudefduf bengalensis (Bloch, 1787)
• Abudefduf lorenzi Hensley & Allen, 1977
• Abudefduf notatus (Day, 1870)
• Abudefduf septemfasciatus (Cuvier, 1830)
• Abudefduf sexfasciatus (Lacepède, 1801)
• Abudefduf sordidus (Forsskål, 1775)
• Abudefduf vaigiensis (Quoy & Gaimard, 1825)
• Abyla bicarinata Moser, 1925
• Abyla brownia Sears, 1953 accepted as Abyla bicarinata Moser, 1925
• Abyla carina Haeckel, 1888 accepted as Abyla trigona Quoy & Gaimard, 1827
• Abyla haeckeli Lens & van Riemsdijk, 1908
• Abyla ingeborgae Sears, 1953 accepted as Abyla haeckeli Lens & van Riemsdijk, 1908
• Abyla peruana Sears, 1953 accepted as Abyla trigona Quoy & Gaimard, 1827
• Abyla schmidti Sears, 1953 accepted as Abyla trigona Quoy & Gaimard, 1827
• Abyla tottoni Sears, 1953 accepted as Abyla bicarinata Moser, 1925
• Abyla trigona Quoy & Gaimard, 1827
• Abylopsis eschscholtzii (Huxley, 1859)
• Abylopsis tetragona (Otto, 1823)
• Acabaria formosa Nutting, 1911 accepted as Melithaea formosa (Nutting, 1911)
• Acabaria philippinensis (Wright & Studer, 1889) accepted as Melithaea philippinensis (Wright & Studer, 1889)
• Acalyptophis peronii (Duméril, 1853) accepted as Hydrophis peronii (Duméril, 1853)
• Acanthacaris tenuimana Spence Bate, 1888
• Acanthaphritis barbata (Okamura & Kishida, 1963)
• Acanthaphritis grandisquamis Günther, 1880
• Acanthaphritis unoorum Suzuki & Nakabo, 1996
• Acanthaster planci (Linnaeus, 1758)
• Acanthastrea echinata (Dana, 1846)
• Acanthastrea hillae Wells, 1955 accepted as Homophyllia bowerbanki (Milne Edwards & Haime, 1857)
• Acanthaxius formosa Kensley & Chan, 1998
• Acanthaxius grandis Kensley & Chan, 1998
• Acanthaxius polyacanthus (Miyake & Sakai, 1967)
• Acanthella acuta Schmidt, 1862
• Acanthella dendyi (Bergquist, 1970)
• Acanthella mastophora (Schmidt, 1870)
• Acanthella oviforma Tanita & Hoshino, 1989
• Acanthella vulgata Thiele, 1898
• Acanthephyra armata A. Milne-Edwards, 1881
• Acanthephyra carinata Spence Bate, 1888
• Acanthephyra curtirostris Wood-Mason in Wood-Mason & Alcock, 1891
• Acanthephyra eximia Smith, 1884
• Acanthephyra purpurea A. Milne-Edwards, 1881
• Acanthocepola indica (Day, 1888)
• Acanthocepola krusensterni (Temminck & Schlegel, 1845) accepted as Acanthocepola krusensternii (Temminck & Schlegel, 1845)
• Acanthocepola krusensternii (Temminck & Schlegel, 1845)
• Acanthocepola limbata (Valenciennes, 1835)
• Acanthochiton dissimilis Is. Taki & Iw. Taki, 1931 accepted as Acanthochitona dissimilis Is. Taki & Iw. Taki, 1931
• Acanthochiton zelandicus (Quoy & Gaimard, 1835) accepted as Acanthochitona zelandica (Quoy & Gaimard, 1835)
• Acanthochitona achates (A. Gould, 1859)
• Acanthochitona armata (Pease, 1872)
• Acanthochitona dissimilis Is. Taki & Iw. Taki, 1931
• Acanthochitona rubrolineata (Lischke, 1873)
• Acanthochitona scutigera (Reeve, 1847)
• Acanthochitona zelandica (Quoy & Gaimard, 1835)
• Acanthochondrites annulatus (Olsson, 1869)
• Acanthocolpus acanthocepolae Shen, 1990
• Acanthocolpus liodorus Lühe, 1906
• Acanthocolpus plageorchis (Shen, 1989) Martin, Cutmore & Cribb, 2018
• Acanthocolpus sanyaensis Shen, 1990
• Acanthocybium solandri (Cuvier, 1832)
• Acanthodesia grandicella Canu & Bassler, 1929 accepted as Biflustra grandicella (Canu & Bassler, 1929)
• Acanthodesia irregulata (Liu, 1991) accepted as Biflustra irregulata (Liu, 1991)
• Acanthodesia savartii (Audouin, 1826) accepted as Biflustra savartii (Audouin, 1826)
• Acanthodoris pilosa (Abildgaard, 1789)
• Acanthogobius flavimanus (Temminck & Schlegel, 1845)
• Acanthogobius hasta (Temminck & Schlegel, 1845)
• Acanthogobius lactipes (Hilgendorf, 1879)