• Spio Brady & Robertson, 1876 accepted as Delavalia Brady, 1869
• Spio Fabricius, 1785
• Spio (Microspio) Mesnil, 1896 accepted as Microspio Mesnil, 1896
• Spio (Microspio) gaucha Orensanz & Gianuca, 1974 accepted as Scolelepis gaucha (Orensanz & Gianuca, 1974)
• Spio (Microspio) mecznikowiana (Claparède, 1869) accepted as Microspio mecznikowiana (Claparède, 1869)
• Spio acuta Treadwell, 1914 accepted as Scolelepis (Scolelepis) acuta (Treadwell, 1914)
• Spio aequalis Ehlers, 1904
• Spio africana (Rullier, 1964) accepted as Dispio africana (Rullier, 1964)
• Spio arctica (Soderstrom, 1920) accepted as Spio limicola Verrill, 1879
• Spio armata (Thulin, 1957)
• Spio arndti Meißner, Bick & Bastrop, 2011
• Spio atlanticus Langerhans, 1880 accepted as Microspio atlantica (Langerhans, 1880)
• Spio bengalensis Willey, 1908
• Spio blakei Maciolek, 1990
• Spio bombyx Claparède, 1870 accepted as Spiophanes bombyx (Claparède, 1870)
• Spio borealis Okuda, 1937
• Spio brunnea Brady & Robertson, 1876 accepted as Delavalia longicaudata (Boeck, 1873)
• Spio butleri Berkeley & Berkeley, 1954
• Spio butleri kurilensis Buzhinskaya, 1990 accepted as Spio kurilensis Buzhinskaya, 1990
• Spio calcarea Templeton, 1836 accepted as Polydora calcarea (Templeton, 1836)
• Spio californica Fewkes, 1889 (uncertain > nomen dubium)
• Spio caudatus Lamarck, 1818 accepted as Polydora cornuta Bosc, 1802
• Spio caudatus sensu Delle Chiaje, 1827 accepted as Neanthes acuminata (Ehlers, 1868)
• Spio celata Dalyell, 1853
• Spio cirrata König [pre-Linnaean] accepted as Amphitrite cirrata Müller, 1776
• Spio cirrifera (Banse & Hobson, 1968)
• Spio coccineus Delle Chiaje, 1822 accepted as Platynereis coccinea (Delle Chiaje, 1822)
• Spio crenaticornis Montagu, 1816 (uncertain > taxon inquirendum)
• Spio decorata Bobretzky, 1870
• Spio decoratus Bobretzky, 1870 accepted as Spio decorata Bobretzky, 1870
• Spio filicornis (Müller, 1776)
• Spio filicornis pacifica Berkeley, 1936
• Spio filicornis picta Zachs, 1933 accepted as Spio picta Zachs, 1933
• Spio fuliginosus Claparède, 1868 accepted as Malacoceros fuliginosus (Claparède, 1868)
• Spio gattyi McIntosh, 1909 accepted as Spio filicornis (Müller, 1776)
• Spio goniocephala Thulin, 1957
• Spio gorbunovi Averincev, 1990
• Spio hirsuta Treadwell, 1928 accepted as Scolelepis (Scolelepis) squamata (O.F. Muller, 1806)
• Spio inversa Kuhlgatz, 1898 accepted as Pygospio elegans Claparède, 1863
• Spio jirkovi (Sikorski, 1993) accepted as Malacoceros jirkovi Sikorski, 1993
• Spio kurilensis Buzhinskaya, 1990
• Spio laevicornis Rathke, 1837 accepted as Malacoceros laevicornis (Rathke, 1837)
• Spio limicola Verrill, 1879
• Spio maciolekae Blake, 1996
• Spio maculata (Hartman, 1961)
• Spio magnus Day, 1955 accepted as Dispio magna (Day, 1955)
• Spio malmgreni Sikorski in Jirkov, 2001
• Spio martinensis Mesnil, 1896
• Spio martinensis pacifica Berkeley, 1927 accepted as Spio filicornis pacifica Berkeley, 1936
• Spio mecznikowianus Claparède, 1869 accepted as Microspio mecznikowiana (Claparède, 1869)
• Spio mesnili (McIntosh, 1915) (uncertain > taxon inquirendum)
• Spio mesnili Augener, 1914
• Spio mimus Chamberlin, 1920 accepted as Spio theeli (Söderström, 1920)
• Spio multioculata (Rioja, 1918)
• Spio nemertinaeformis Czerniavsky, 1881 accepted as Saccocirrus papillocercus Bobretzky, 1872
• Spio obtusa Ehlers, 1913
• Spio ornatus Perejaslavtseva, 1891
• Spio pacifica Blake & Kudenov, 1978 accepted as Spio blakei Maciolek, 1990
• Spio parva (Dalyell, 1853)
• Spio pettiboneae Foster, 1971
• Spio picta Zachs, 1933
• Spio pigmentata Lee, Meißner, Yoon & Min, 2021
• Spio punctata Hartman, 1961 accepted as Malacoceros indicus (Fauvel, 1928)
• Spio quadricornis Lamarck, 1818 accepted as Spio crenaticornis Montagu, 1816
• Spio quadrisetosa Blake, 1983
• Spio rathbuni Webster & Benedict, 1884 accepted as Pygospio elegans Claparède, 1863
• Spio readi Blake, 1984
• Spio robusta Verrill, 1873 accepted as Spio setosa Verrill, 1873
• Spio seticornis (Linnaeus, 1767)
• Spio setosa Verrill, 1873
• Spio singularis Blake & Kudenov, 1978
• Spio symphyta Meißner, Bick & Bastrop, 2011
• Spio theeli (Söderström, 1920)
• Spio theeli kolaensis (Zachs, 1925)
• Spio thulini Maciolek, 1990
• Spio tridentata Hutchings & Turvey, 1984
• Spio tzetlini Sikorski in Jirkov, 2001
• Spio unidentata Chlebovitsch, 1959
• Spio ventilabrum Delle Chiaje, 1827 accepted as Nereis ventilabrum (Delle Chiaje, 1827)
• Spio viridis Johnston, 1828 accepted as Scolelepis foliosa (Audouin & Milne Edwards, 1833) represented as Scolelepis (Scolelepis) foliosa (Audouin & Milne Edwards, 1833)
• Spio vulgaris Johnston, 1827 accepted as Malacoceros vulgaris (Johnston, 1827)
• Spiochaetopterus M Sars, 1856
• Spiochaetopterus bergensis Gitay, 1969
• Spiochaetopterus challengeriae McIntosh, 1885 accepted as Phyllochaetopterus claparedii McIntosh, 1885
• Spiochaetopterus costarum (Claparède, 1869)
• Spiochaetopterus costarum monroi Gitay, 1969
• Spiochaetopterus costarum oculatus Webster, 1879
• Spiochaetopterus costarum okudai Gitay, 1969 accepted as Spiochaetopterus okudai Gitay, 1969
• Spiochaetopterus costarum pottsi (Berkeley, 1927) accepted as Spiochaetopterus costarum (Claparède, 1869)
• Spiochaetopterus creoceanae Bhaud, Martin & Gil, 2003
• Spiochaetopterus herdmani Hornell in Willey, 1905 accepted as Phyllochaetopterus herdmani (Hornell in Willey, 1905)
• Spiochaetopterus iheyaensis Nishi, 2008
• Spiochaetopterus izuensis Nishi, Bhaud & Koh, 2004
• Spiochaetopterus koreana Bhaud, Koh & Hong, 2002
• Spiochaetopterus madeirensis Langerhans, 1880
• Spiochaetopterus manazuruensis Nishi, 2003
• Spiochaetopterus nonatoi Bhaud & Petti, 2001
• Spiochaetopterus oculatus Webster, 1879
• Spiochaetopterus okinawaensis Nishi & Bhaud, 2000
• Spiochaetopterus okudai Gitay, 1969 (unaccepted > unavailable name)