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Paramoeba spec. with one and two PLOs.

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

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