Family Paramoebidae Poche, 1913, emend. Kudryavtsev et al., 2011
Diagnosis: Flattened dactylopodial amoebae with blunt, hyaline subpseudopodia, conical or finger-shaped in outline. Floating form often with radiating pseudopodia. Uninucleate with central nucleolus.
Cell coat consists of microscales, dense amorphous glycocalyx that may include hair-like structures, or dome-shaped glycostyles with hexagonal bases.
One genus of this family, Paramoeba, contains a deeply-specialized kinetoplastid symbiont Perkinsela amoebae (Hollande, 1980) Dyková et al., 2008 (also called Perkinsela-like organism, PLO, formerly called parasome) located in the cytoplasm near the nucleus.
At the ultrastructural level, two features are of diagnostic importance:
- Surface layer is complex and highly differentiated as a cuticle or as boat-shaped microscales discernable at the TEM level;
- Pseudopodia are without a filamentous core (as in Vexilliferidae).
Key to genera:
1 Cell with PLO > Paramoeba
– Cell without PLO > Korotnevella