| Name | Children | Media (from resource) | Traits |
|---|---|---|---|
| Alveolates | 1 | 0 | 0 |
| Amoeba proteus | 0 | 3 | 0 |
| Amoebidae | 1 | 3 | 0 |
| Amoebozoa (amoeboid protists) | 3 | 216 | 0 |
| Amphitremida | 1 | 2 | 0 |
| Amphizonella violacea Greeff 1866 | 0 | 12 | 0 |
| Amphora ovalis | 0 | 5 | 0 |
| Anabaena Bory de Saint-Vincent ex Bornet & Flahault 1886 | 0 | 4 | 0 |
| Anabaena lapponica | 0 | 1 | 0 |
| Anabaenopsis hungarica Halász 1939 | 0 | 2 | 0 |
| Anabaenopsis milleri Woronichin 1929 | 0 | 1 | 0 |
| Anagnostidinema lemmermannii | 0 | 1 | 0 |
| Anisonema Dujardin 1841 | 0 | 2 | 0 |
| Anisonema acinus | 0 | 1 | 0 |
| Ankistrodesmus Corda 1838 | 0 | 4 | 0 |
