Abra alba (Wood W., 1802)
Abudefduf luridus (Cuvier, 1830)
Abudefduf saxatilis (Linnaeus, 1758)
Acanthella acuta Schmidt, 1862
Acanthocardia aculeata (Linnaeus, 1767)
Acanthocardia echinata (Linnaeus, 1758)
Acanthocardia paucicostata (Sowerby, 1841)
Acanthocardia tuberculata (Linnaeus, 1758)
Acanthochitona crinita (Pennant, 1777)
Acanthochitona fascicularis (Linnaeus, 1767)
Acantholabrus palloni (Risso, 1810)
Acanthonyx lunulatus (Risso, 1816)
Acanthostracion quadricornis (Linnaeus, 1758)
Acasta spongites (Poli, 1795)
Achaeus cranchii Leach, 1817
Achelia vulgaris (Costa, 1861)
Acipenser sturio Linnaeus, 1758
Acteon tornatilis (Linnaeus, 1758)
Actinia equina (Linnaeus, 1758)
Actinia fragacea Tugwell, 1856
Actinothoe sphyrodeta (Gosse, 1858)
Adamsia carciniopados (Otto, 1823)
Adreus fascicularis (Bowerbank, 1866)
Aegires punctilucens (d'Orbigny, 1837)
Aeolidia papillosa (Linnaeus, 1761)
Aequipecten opercularis (Linnaeus, 1758)
Aetea anguina (Linnaeus, 1758)
Aglaophenia kirchenpaueri (Heller, 1868)
Aglaophenia pluma (Linnaeus, 1767)
Aglaophenia tubiformis Marktanner-Turneretscher, 1890
Aglaophenia tubulifera (Hincks, 1861)
Aiptasia mutabilis (Gravenhorst, 1831)
Alcyonium acaule Marion, 1878
Alcyonium coralloides (Pallas, 1766)
Alcyonium digitatum Linnaeus, 1758
Alcyonium glomeratum (Hassal, 1843)
Alcyonium palmatum Pallas, 1766
Alentia gelatinosa (M. Sars, 1835)
Alicia mirabilis Johnson, 1861
Alopias superciliosus (Lowe, 1841)