• Acaenomolgus protulae (Stock, 1959)
• Acaenomolgus serpulae (Stock, 1960)
• Acanthochondria clavata (Bassett-Smith, 1896)
• Acanthochondria cornuta (Müller O.F., 1776)
• Acanthochondria limandae (Krøyer, 1863)
• Acanthochondria soleae (Krøyer, 1838)
• Acanthochondria triglae Herrera-Cubilla & Raibaut, 1990
• Acanthochondrites annulatus (Olsson, 1869)
• Acanthocyclops vernalis (Fischer, 1853) represented as Acanthocyclops vernalis vernalis (Fischer, 1853)
• Acanthocyclops vernalis vernalis (Fischer, 1853)
• Acartia (Acanthacartia) bifilosa (Giesbrecht, 1881)
• Acartia (Acanthacartia) fossae Gurney, 1927
• Acartia (Acanthacartia) italica Steuer, 1910
• Acartia (Acanthacartia) plumosa Scott T., 1894
• Acartia (Acanthacartia) tonsa Dana, 1849
• Acartia (Acartia) danae Giesbrecht, 1889
• Acartia (Acartia) forcipata Thompson I.C. & Scott A., 1897 in Thompson, Scott & Herdman, 1897
• Acartia (Acartia) negligens Dana, 1849
• Acartia (Acartiura) clausi Giesbrecht, 1889
• Acartia (Acartiura) discaudata (Giesbrecht, 1881)
• Acartia (Acartiura) enzoi Crisafi, 1974
• Acartia (Acartiura) hudsonica Pinhey, 1926
• Acartia (Acartiura) lefevreae Bradford, 1976
• Acartia (Acartiura) longiremis (Lilljeborg, 1853)
• Acartia (Acartiura) margalefi Alcaraz, 1976
• Acartia (Acartiura) teclae Bradford, 1976
• Acartia (Hypoacartia) adriatica Steuer, 1910
• Acartia (Odontacartia) centrura Giesbrecht, 1889
• Acartia adriatica Steuer, 1910 represented as Acartia (Hypoacartia) adriatica Steuer, 1910
• Acartia bifilosa (Giesbrecht, 1881) represented as Acartia (Acanthacartia) bifilosa (Giesbrecht, 1881)
• Acartia centrura Giesbrecht, 1889 represented as Acartia (Odontacartia) centrura Giesbrecht, 1889
• Acartia clausi Giesbrecht, 1889 represented as Acartia clausii Giesbrecht, 1889 represented as Acartia (Acartiura) clausi Giesbrecht, 1889
• Acartia clausii Giesbrecht, 1889 represented as Acartia (Acartiura) clausi Giesbrecht, 1889
• Acartia danae Giesbrecht, 1889 represented as Acartia (Acartia) danae Giesbrecht, 1889
• Acartia discaudata (Giesbrecht, 1882) represented as Acartia (Acartiura) discaudata (Giesbrecht, 1881)
• Acartia enzoi Crisafi, 1974 represented as Acartia (Acartiura) enzoi Crisafi, 1974
• Acartia forcipata Thompson I.C. & Scott A. in Thompson, Scott & Herdman, 1897 represented as Acartia (Acartia) forcipata Thompson I.C. & Scott A., 1897 in Thompson, Scott & Herdman, 1897
• Acartia fossae Gurney, 1927 represented as Acartia (Acanthacartia) fossae Gurney, 1927
• Acartia grani Sars G.O., 1904 accepted as Paracartia grani Sars G.O., 1904 represented as Paracartia grani grani Sars G.O., 1904
• Acartia hudsonica Pinhey, 1926 represented as Acartia (Acartiura) hudsonica Pinhey, 1926
• Acartia italica Steuer, 1910 represented as Acartia (Acanthacartia) italica Steuer, 1910
• Acartia latisetosa (Krichagin, 1873) accepted as Paracartia latisetosa (Krichagin, 1873)
• Acartia lefevreae Bradford, 1976 represented as Acartia (Acartiura) lefevreae Bradford, 1976
• Acartia longiremis (Lilljeborg, 1853) represented as Acartia (Acartiura) longiremis (Lilljeborg, 1853)
• Acartia margalefi Alcaraz, 1976 represented as Acartia (Acartiura) margalefi Alcaraz, 1976
• Acartia negligens Dana, 1849 represented as Acartia (Acartia) negligens Dana, 1849
• Acartia plumosa Scott T., 1894 represented as Acartia (Acanthacartia) plumosa Scott T., 1894
• Acartia teclae Bradford, 1976 represented as Acartia (Acartiura) teclae Bradford, 1976
• Acartia tonsa Dana, 1849 represented as Acartia (Acanthacartia) tonsa Dana, 1849
• Achtheres percarum von Nordmann, 1832
• Acontiophorus antennatus Hansen, 1923
• Acontiophorus armatus Brady, 1880
• Acontiophorus bracatus Stock & Kleeton, 1963 accepted as Orecturus bracatus (Stock & Kleeton, 1963)
• Acontiophorus ornatus (Brady & Robertson, 1876)
• Acontiophorus scutatus (Brady & Robertson, 1873)
• Acrenhydrosoma perplexum (Scott T., 1899)
• Acrocalanus andersoni Bowman, 1958
• Acrocalanus gibber Giesbrecht, 1888
• Acrocalanus longicornis Giesbrecht, 1888
• Aculeopsis longisetosa Huys & Willems, 1989
• Advena paradoxa (Beneden, 1851) accepted as Kabatazus paradoxus (van Beneden, 1851)
• Aegisthus aculeatus Giesbrecht, 1891
• Aegisthus atlanticus Wolfenden, 1902 accepted as Aegisthus mucronatus Giesbrecht, 1891
• Aegisthus mucronatus Giesbrecht, 1891
• Aegisthus spinulosus Farran, 1905
• Aetideopsis armata (Boeck, 1872)
• Aetideopsis armatus (Boeck, 1872) accepted as Aetideopsis armata (Boeck, 1872)
• Aetideopsis carinata Bradford, 1969
• Aetideopsis minor (Wolfenden, 1911)
• Aetideopsis modesta (With, 1915) accepted as Aetideopsis minor (Wolfenden, 1911)
• Aetideopsis multiserrata (Wolfenden, 1904)
• Aetideopsis rostrata Sars G.O., 1903
• Aetideus acutus Farran, 1929
• Aetideus arcuatus (Vervoort, 1949)
• Aetideus armatus (Boeck, 1872)
• Aetideus giesbrechti Cleve, 1904
• Afrolaophonte pori Masry, 1970
• Afroleptastacus remanei (Noodt, 1964)
• Agetus flaccus (Giesbrecht, 1891)
• Agetus limbatus (Brady, 1883)
• Agetus typicus Krøyer, 1849
• Agnathaner freemani Hammond, 1968 accepted as Pachypygus freemani (Hammond, 1968)
• Agnathaner minutus Canu, 1892 accepted as Pachypygus gibber (Thorell, 1859)
• Agnathaner typicus Canu, 1892 accepted as Pachypygus typicus (Canu, 1892)
• Aigondiceps bocki (Lang, 1948)
• Aigondiceps brevicauda (Huys, 1995)
• Aigondiceps kunzi (Marinov, 1974)
• Akessonia occulta Bresciani & Lützen, 1962
• Albionella fabricii Rubec & Hogans, 1988 accepted as Neoalbionella fabricii (Rubec & Hogans, 1988)
• Albionella globosa (Leigh-Sharpe, 1918) accepted as Neoalbionella globosa (Leigh-Sharpe, 1918)
• Alebion carchariae Krøyer, 1863
• Alebion crassus Wilson C.B., 1932
• Alella macrotrachelus (Brian, 1906) accepted as Alella pagelli (Krøyer, 1863)
• Alella pagelli (Krøyer, 1863)
• Allantogynus delamarei Changeux, 1960
• Alteutha aberrans Czerniavski, 1868
• Alteutha austrina Scott T., 1912 accepted as Alteutha depressa (Baird, 1837)
• Alteutha depressa (Baird, 1837)
• Alteutha dubia Scott T., 1912
• Alteutha interrupta (Goodsir, 1845)