Amphipholis, Genus
Amphisternata, Subordo
Amphiura, Genus
Amphiuridae, Familia
Animalia, Regnum
Anseropoda, Genus
Antedon, Genus
Antedonidae, Familia
Apoda, Ordo
Apodida Brandt, 1835, Ordo
– synonym of Apoda, Ordo
Asterias, Genus
Asteriidae, Familia
Asterinidae, Familia
Asteroidea, Classis
Astropecten, Genus
Astropectinidae, Familia