Rhizamoeba spec. c. 130 µm wide - Florida, garden pond

 

 

Genus Rhizamoeba Page, 1972 emend. Smirnov et al., 2016

 

Diagnosis: Amoebae altering locomotive morphology from limax-like to flabellate, fan-shaped and possessing collosomes in a single studied species. Uninucleate or possessing limited number (less than 50) nuclei. Cells never adopt expanded, comet-like shapes.
Ultrastructure: In the SSU rDNA sequence remarkable deletion of ca. 20 bp starting from the positions 278 (in the sequence EU719197
Rhizamoeba saxonica CCAP1570/2) (against sequences of Flabellula spp.)

Type species: Rhizamoeba polyura Page, 1972

Known species:

1. Rhizamoeba saxonica Page, 1974
2. Rhizamoeba polyura Page, 1972
3. Rhizamoeba matisi Mrva, 2016

 

Ecology: Rhizamoeba-species aren't rare, but often hard to find because they hide usually under debris.

 

Rhizamoeba clavarioides
Rhizamoeba clavarioides; N Nucleus; B Distinct border between hyaline zone and body; T Trailing filaments
Rhizamoeba clavarioides
Characteristic flow back of hyaloplasm along one side.
Rhizamoeba-spec
Rhizamoeba spec, with very long trailing filaments (arrowed). The largest part of the cell is out of focus.