• Abarenicola affinis (Ashworth, 1903): very sensitive to disturbance
• Abarenicola claparedi (Levinsen, 1884): very sensitive to disturbance
• Abra aequalis (Say, 1822): very sensitive to disturbance
• Abra prismatica (Montagu, 1808): very sensitive to disturbance
• Abyssoninoe hibernica (McIntosh, 1903): very sensitive to disturbance
• Abyssoninoe scopa (Fauchald, 1974): very sensitive to disturbance
• Acanthocardia aculeata (Linnaeus, 1758): very sensitive to disturbance
• Acanthocardia echinata (Linnaeus, 1758): very sensitive to disturbance
• Acanthocardia paucicostata (G. B. Sowerby II, 1834): very sensitive to disturbance
• Acanthocardia tuberculata (Linnaeus, 1758): very sensitive to disturbance
• Acanthochitona crinita (Pennant, 1777): very sensitive to disturbance
• Acanthochitona fascicularis (Linnaeus, 1767): very sensitive to disturbance
• Acanthochitona scutigera (Reeve, 1847): very sensitive to disturbance
• Acanthodoris hudsoni MacFarland, 1905: very sensitive to disturbance
• Acanthodoris rhodoceras T. D. A. Cockerell, 1905: very sensitive to disturbance
• Acanthohaustorius intermedius Bousfield, 1965: very sensitive to disturbance
• Acanthohaustorius millsi Bousfield, 1965: very sensitive to disturbance
• Acanthonyx lunulatus (Risso, 1816): very sensitive to disturbance
• Acetes chinensis Hansen, 1919: very sensitive to disturbance
• Acetes indicus H. Milne Edwards, 1830: very sensitive to disturbance
• Achaeus cranchii Leach, 1817: very sensitive to disturbance
• Achaeus gracilis (O.G. Costa, 1839): very sensitive to disturbance
• Achelia assimilis (Haswell, 1885): very sensitive to disturbance
• Achelia echinata Hodge, 1864: very sensitive to disturbance
• Achelia laevis Hodge, 1864: very sensitive to disturbance
• Achelia langi (Dohrn, 1881): very sensitive to disturbance
• Achelia simplex (Giltay, 1934): very sensitive to disturbance
• Achelia simplissima (Hilton, 1939): very sensitive to disturbance
• Achelia vulgaris (Costa, 1861): very sensitive to disturbance
• Achelous ordwayi Stimpson, 1860: very sensitive to disturbance
• Acidostoma obesum (Spence Bate & Westwood, 1861): very sensitive to disturbance
• Aclis gulsonae (W. Clark, 1850): very sensitive to disturbance
• Aclis minor (T. Brown, 1827): very sensitive to disturbance
• Acoetes jogasimae (Izuka, 1912): very sensitive to disturbance
• Acoetes melanonota (Grube, 1876): very sensitive to disturbance
• Acrocnida brachiata (Montagu, 1804): very sensitive to disturbance
• Acteocina bullata (Kiener, 1834): very sensitive to disturbance
• Acteocina canaliculata (Say, 1826): very sensitive to disturbance
• Acteocina conspicua (Preston, 1908): very sensitive to disturbance
• Acteocina koyasensis (Yokoyama, 1927): very sensitive to disturbance
• Acteon biplicatus (Melleville, 1843) †: very sensitive to disturbance
• Acteon delicatus Dall, 1889: very sensitive to disturbance
• Acteon tornatilis (Linnaeus, 1758): very sensitive to disturbance
• Actinia equina (Linnaeus, 1758): very sensitive to disturbance
• Actinocythereis dunelmensis (Norman, 1865): very sensitive to disturbance
• Adamussium colbecki (E. A. Smith, 1902): very sensitive to disturbance
• Admete viridula (O. Fabricius, 1780): very sensitive to disturbance
• Aegires albopunctatus MacFarland, 1905: very sensitive to disturbance
• Aeolidia papillosa (Linnaeus, 1761): very sensitive to disturbance
• Aequipecten opercularis (Linnaeus, 1758): very sensitive to disturbance
• Aesopus aliciae Marincovich, 1973: very sensitive to disturbance
• Agladrillia fuegiensis (E. A. Smith, 1888): very sensitive to disturbance
• Aglaja ocelligera (Bergh, 1894): very sensitive to disturbance
• Aglaophamus dibranchis (Grube, 1877): very sensitive to disturbance
• Aidanosagitta crassa (Tokioka, 1938): very sensitive to disturbance
• Akanthophoreus gracilis (Krøyer, 1842): very sensitive to disturbance
• Akera bullata O. F. Müller, 1776: very sensitive to disturbance
• Albunea carabus (Linnaeus, 1758): very sensitive to disturbance
• Alderia modesta (Lovén, 1844): very sensitive to disturbance
• Alia unifasciata (G. B. Sowerby I, 1832): very sensitive to disturbance
• Alvania beanii (Hanley, 1844): very sensitive to disturbance
• Alvania cancellata (da Costa, 1778): very sensitive to disturbance
• Alvania cimex (Linnaeus, 1758): very sensitive to disturbance
• Alvania cimicoides (Forbes, 1844): very sensitive to disturbance
• Alvania colossophilus Oberling, 1970: very sensitive to disturbance
• Alvania geryonia (Nardo, 1847): very sensitive to disturbance
• Alvania punctura (Montagu, 1803): very sensitive to disturbance
• Alvania testae (Aradas & Maggiore, 1844): very sensitive to disturbance
• Alveinus ojianus (Yokoyama, 1927): very sensitive to disturbance
• Amaeana trilobata (Sars, 1863): very sensitive to disturbance
• Amage adspersa (Grube, 1863): very sensitive to disturbance
• Amage auricula Malmgren, 1866: very sensitive to disturbance
• Amakusanthura iberica Reboreda & Wägele, 1992: very sensitive to disturbance
• Amakusanthura magnifica (Menzies & Frankenberg, 1966): very sensitive to disturbance
• Amakusanthura signata (Menzies & Glynn, 1968): very sensitive to disturbance
• Amastigos caperatus Ewing & Dauer, 1981: very sensitive to disturbance
• Amathia gracilis (Leidy, 1855): very sensitive to disturbance
• Amathia imbricata (Adams, 1800): very sensitive to disturbance
• Amathia lendigera (Linnaeus, 1758): very sensitive to disturbance
• Amathia pruvoti Calvet, 1911: very sensitive to disturbance
• Americhelidium gurjanovae (Kudrjaschov & Tzvetkova, 1975): very sensitive to disturbance
• Americorophium salmonis (Stimpson, 1857): very sensitive to disturbance
• Americorophium stimpsoni (Shoemaker, 1941): very sensitive to disturbance
• Ameritella tenella (A. E. Verrill, 1874): very sensitive to disturbance
• Ameritella texana (Dall, 1900): very sensitive to disturbance
• Ameroculodes edwardsi (Holmes, 1905): very sensitive to disturbance
• Ammothella longipes (Hodge, 1864): very sensitive to disturbance
• Ampelisca aequicornis Bruzelius, 1859: very sensitive to disturbance
• Ampelisca agassizi (Judd, 1896): very sensitive to disturbance
• Ampelisca amblyops G.O. Sars, 1891: very sensitive to disturbance
• Ampelisca anomala G.O. Sars, 1883: very sensitive to disturbance
• Ampelisca armoricana Bellan-Santini & Dauvin, 1981: very sensitive to disturbance
• Ampelisca bocki Dahl, 1944: very sensitive to disturbance
• Ampelisca brevicornis (A. Costa, 1853): very sensitive to disturbance
• Ampelisca cavicoxa Reid, 1951: very sensitive to disturbance
• Ampelisca cyclops Walker, 1904: very sensitive to disturbance
• Ampelisca dalmatina Karaman, 1975: very sensitive to disturbance
• Ampelisca eoa Gurjanova, 1951: very sensitive to disturbance
• Ampelisca eschrichtii Krøyer, 1842: very sensitive to disturbance
• Ampelisca gibba G.O. Sars, 1883: very sensitive to disturbance