| Name | Children | Media (from resource) | Traits |
|---|---|---|---|
| Achaeus cadelli Alcock 1895 | 0 | 0 | 1 |
| Achaeus curvirostris (A. Milne-Edwards 1873) | 0 | 0 | 1 |
| Acinetosporaceae | 2 | 0 | 0 |
| Acmaea Eschscholtz 1833 | 1 | 0 | 0 |
| Acmaea achates (Reeve 1855) | 0 | 0 | 1 |
| Acmaeidae Forbes 1850 (acmaeid sea snails) | 1 | 0 | 0 |
| Acochlidioidea Küthe 1935 | 1 | 0 | 0 |
| Acoela (acoel flatworms) | 2 | 0 | 0 |
| Acoetidae | 2 | 0 | 0 |
| Acontiophoridae Carlgren 1938 | 1 | 0 | 0 |
| Acontiophorum | 1 | 0 | 0 |
| Acontiophorum bombayense Parulekar 1968 | 0 | 0 | 1 |
| Acraea | 1 | 0 | 0 |
| Acraea terpsichore Linnaeus 1758 | 0 | 0 | 1 |
| Acraea violae Fabricius 1775 | 0 | 0 | 1 |
