Abra, Genus
Acanthodoris, Genus
Actinia, Genus
Aeolidia, Genus
Aeolidiella, Genus
Aglaothamnion, Genus
Agonidae, Familia
Agonus, Genus
Alcyonidium, Genus
Alcyonium, Genus
Amphipoda, Ordo
Angiospermophyta, Phylum
Anguilla, Genus
Anguillidae, Familia
Anguilliformes, Ordo
Anguinella, Genus
Animalia, Regnum
Annelida, Phylum
Anthozoa, Subphylum
Anurida, Genus
Aphrodita, Genus
Aphroditoidea, Ordo
Aplidium, Genus
Archidoris, Genus
Arctica, Genus
Arenicola, Genus
Arthropoda, Phylum
Ascidiella, Genus
Ascophyllum, Genus
Asterias, Genus
Asteroidea, Classis
Astropecten, Genus
Athecata, Subordo
Atherina, Genus
Atherinidae, Familia
Atheriniformes, Ordo
Aurelia, Genus