Flamella fluviatilis Kudryavtsev et al., 2009
Diagnosis: During locomotion generally irregular, fan-shaped, with a broadly extended posterior edge producing numerous long trailing filaments. Observed length during locomotion 13-32 µm (average 21 µm), breadth 17-56 µm (average36 µm), length to breadth ratio 0.39-0.84 (average 0.59). Spherical or ovoid vesicular nucleus 4-6 µm in diameter (average 4.7 µm), with a central nucleolus 1.8-3.2 µm in diameter (average 2.3 µm); large motile cells with up to 15-20 nuclei maybe present in cultures. About 15 asynchronously working contractile vacuoles in the granuloplasm. Uninucleate cysts 10.7-23.4 µm in diameter (average 15.5 µm); multinucleate cysts, and several uninucleate cysts under a common cyst wall may be present in culture; diameter of multinucleate cysts about 40-50 µm. Cyst wall 200-290 nm thick; homogeneous innermost layer of the cyst wall continuous, 66-100 nm thick; outer layer coarsely granular, 116-190 nm thick, contains ostioles with opercula 1.3-1.4 µm in diameter; in some places outer layer splits into two sheets, the outer one (36-54 nm thick) corresponding to ectocyst.
Ecology: Murray river, Australia, freshwater, aerobic.