Family Amoebidae Ehrenberg, 1838
Diagnosis: Locomotive amoebae usually larger than 80 µm in length, with cylindrical pseudopodia with hyaline caps. Some species are monopodial but most are polypodial. Many have cytoplasmic crystals. Nucleus often with nuclear material in small fragments.
Key to the genera:
1 | Amoeba multinucleate | 2 |
– | Amoeba usually with one nucleus | 3 |
2 | Amoeba usually polypodial, with longitudinal ridges | |
– | Amoeba usually monopodial, without longitudinal ridges | |
3 | Amoeba monopodial, only branched when changing direction | 4 |
– | Amoeba usually polypodial | 5 |
4 | Amoeba free-living | |
– | Amoeba parasitic on freshwater coelenterates (hydra) | |
5 | Amoeba usually > 200 µm; nucleus granular | 6 |
– | Amoeba usually < 200 µm; nucleus with few nucleolar pieces | |
6 | With longitudinal ridges | |
– | Without longitudinal ridges |