• Aaptos aaptos (Schmidt, 1864): filter feeder
• Aaptos alphiensis Samaai & Gibbons, 2005: filter feeder
• Aaptos bergmanni de Laubenfels, 1950: filter feeder
• Aaptos ciliata (Wilson, 1925): filter feeder
• Aaptos conferta Kelly-Borges & Bergquist, 1994: filter feeder
• Aaptos duchassaingi (Topsent, 1889): filter feeder
• Aaptos durissima (Carter, 1882): filter feeder
• Aaptos globosa Kelly-Borges & Bergquist, 1994: filter feeder
• Aaptos glutinans Moraes, 2011: filter feeder
• Aaptos hajdui Carvalho, da Silva & Pinheiro, 2013: filter feeder
• Aaptos horrida (Carter, 1886): filter feeder
• Aaptos hoshinoi Van Soest, 2024: filter feeder
• Aaptos incrustans Payne, Samaai & Gibbons, 2025: filter feeder
• Aaptos kanuux Lehnert, Hocevar & Stone, 2008: filter feeder
• Aaptos laxosuberites (Sollas, 1902): filter feeder
• Aaptos lobata Calcinai, Bastari, Bertolino & Pansini, 2017: filter feeder
• Aaptos nuda (Kirkpatrick, 1903): filter feeder
• Aaptos papillata (Keller, 1880): filter feeder
• Aaptos pernucleata (Carter, 1870): filter feeder
• Aaptos potiguarensis Carvalho, da Silva & Pinheiro, 2013: filter feeder
• Aaptos robustus Plotkin & Janussen, 2008: filter feeder
• Aaptos rosacea Kelly-Borges & Bergquist, 1994: filter feeder
• Aaptos simplex (Lambe, 1893): filter feeder
• Aaptos suberitoides (Brøndsted, 1934): filter feeder
• Aaptos tenta Kelly-Borges & Bergquist, 1994: filter feeder
• Aaptos vannamei de Laubenfels, 1935: filter feeder
• Abathescalpellum fissum (Hoek, 1907): filter feeder
• Abathescalpellum koreanum (Hiro, 1933): filter feeder
• Abramovia pteroidea Baranov in Baranov & Schiskina, 1995 †: filter feeder
• Absenticosta bruntoneileenae Taboada & Shi, 2011 †: filter feeder
• Absenticosta uldzejtuensis Suursuren & Lazarev in Lazarev, 1991 †: filter feeder
• Abyssascidia millari Monniot F., 1971: filter feeder
• Abyssascidia pedunculata Sluiter, 1904: filter feeder
• Abyssascidia wyvillii Herdman, 1880: filter feeder
• Abyssorhynchia craneana (Dall, 1895): filter feeder
• Abyssothyris briggsi Cooper, 1978 †: filter feeder
• Abyssothyris wyvillei (Davidson, 1878): filter feeder
• Acalle recurvata (Bowerbank, 1863): filter feeder
• Acambona prima White, 1862 †: filter feeder
• Acanthalosia deari (Briggs, 1998) †: filter feeder
• Acanthalosia domina Waterhouse, 1986 †: filter feeder
• Acanthalosia mcclungi (Briggs, 1998) †: filter feeder
• Acanthalosia mysteriosa Waterhouse, 2010 †: filter feeder
• Acanthambonia delicata Holmer, 1989 †: filter feeder
• Acanthambonia klabavensis Havliček, 1982 †: filter feeder
• Acanthambonia minutisima Cooper, 1956 †: filter feeder
• Acanthambonia portranensis Wright, 1963 †: filter feeder
• Acanthambonia virginiensis Cooper, 1956 †: filter feeder
• Acanthancora aenigma (Lundbeck, 1910): filter feeder
• Acanthancora coralliophila van Soest, 1984: filter feeder
• Acanthancora cyanocrypta (de Laubenfels, 1930): filter feeder
• Acanthancora equiformis Sim-Smith, Hickman & Kelly, 2021: filter feeder
• Acanthancora schmidti (Topsent, 1898): filter feeder
• Acanthancora stylifera Burton, 1959: filter feeder
• Acanthascus (Acanthascus) alani Ijima, 1898: filter feeder
• Acanthascus (Acanthascus) cactus Schulze, 1886: filter feeder
• Acanthascus (Acanthascus) koltuni Reiswig & Stone, 2013: filter feeder
• Acanthascus (Acanthascus) malacus Reiswig, 2014: filter feeder
• Acanthascus (Acanthascus) pachyderma Okada, 1932: filter feeder
• Acanthascus (Acanthascus) platei Schulze, 1899: filter feeder
• Acanthascus (Acanthascus) profundus Koltun, 1967: filter feeder
• Acanthascus (Acanthascus) sacculus Ferrer Hernández, 1932: filter feeder
• Acanthascus (Rhabdocalyptus) arcticus (Brøndsted, 1916): filter feeder
• Acanthascus (Rhabdocalyptus) asper (Schulze, 1899): filter feeder
• Acanthascus (Rhabdocalyptus) australis (Topsent, 1901): filter feeder
• Acanthascus (Rhabdocalyptus) baculifer (Schulze, 1904): filter feeder
• Acanthascus (Rhabdocalyptus) bidentatus (Okada, 1932): filter feeder
• Acanthascus (Rhabdocalyptus) borealis (Okada, 1932): filter feeder
• Acanthascus (Rhabdocalyptus) capillatus (Ijima, 1897): filter feeder
• Acanthascus (Rhabdocalyptus) dawsoni (Lambe, 1893): filter feeder
• Acanthascus (Rhabdocalyptus) gomezi (Tabachnick & Fromont, 2019): filter feeder
• Acanthascus (Rhabdocalyptus) heteraster (Okada, 1932): filter feeder
• Acanthascus (Rhabdocalyptus) lophodigitatus (Kirkpatrick, 1901): filter feeder
• Acanthascus (Rhabdocalyptus) mirabilis (Schulze, 1899): filter feeder
• Acanthascus (Rhabdocalyptus) mollis (Schulze, 1886): filter feeder
• Acanthascus (Rhabdocalyptus) monstraster (Tabachnick, 1994): filter feeder
• Acanthascus (Rhabdocalyptus) nodulosus (Schulze, 1899): filter feeder
• Acanthascus (Rhabdocalyptus) tener (Schulze, 1899): filter feeder
• Acanthascus (Rhabdocalyptus) tenuis (Schulze, 1899): filter feeder
• Acanthascus (Rhabdocalyptus) trichotis (Reiswig, 2018): filter feeder
• Acanthascus (Rhabdocalyptus) unguiculatus (Ijima, 1904): filter feeder
• Acanthascus (Rhabdocalyptus) victor (Ijima, 1897): filter feeder
• Acanthascus (Staurocalyptus) affinis (Ijima, 1904): filter feeder
• Acanthascus (Staurocalyptus) celebesianus (Ijima, 1927): filter feeder
• Acanthascus (Staurocalyptus) dowlingi (Lambe, 1893): filter feeder
• Acanthascus (Staurocalyptus) entacanthus (Ijima, 1904): filter feeder
• Acanthascus (Staurocalyptus) fasciculatus (Schulze, 1899): filter feeder
• Acanthascus (Staurocalyptus) fuca (Tabachnick, 1989): filter feeder
• Acanthascus (Staurocalyptus) glaber (Ijima, 1897): filter feeder
• Acanthascus (Staurocalyptus) hamatus (Lendenfeld, 1915): filter feeder
• Acanthascus (Staurocalyptus) heteractinus (Ijima, 1897): filter feeder
• Acanthascus (Staurocalyptus) microchetus (Ijima, 1898): filter feeder
• Acanthascus (Staurocalyptus) pamelaturnerae (Reiswig, 2018): filter feeder
• Acanthascus (Staurocalyptus) pleorhaphides (Ijima, 1897): filter feeder
• Acanthascus (Staurocalyptus) psilosus (Reiswig & Stone, 2013): filter feeder
• Acanthascus (Staurocalyptus) roeperi (Schulze, 1886): filter feeder
• Acanthascus (Staurocalyptus) rugocruciatus (Okada, 1932): filter feeder
• Acanthascus (Staurocalyptus) solidus (Schulze, 1899): filter feeder
• Acanthascus (Staurocalyptus) tubulosus (Ijima, 1904): filter feeder
• Acanthascus (Staurocalyptus) tylotus (Reiswig & Stone, 2013): filter feeder