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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Metromonas

Metromonas Larsen & Patterson, 1990 (ref. ID; 6733)

[ref. ID; 5694]
Free-living heterotrophic flagellates. (ref. ID; 5694)
  1. Metromonas simplex (Griessmann, 1913) Larsen & Patterson, 1990 (ref. ID; 4872 Protista Incertae sedis)

Metromonas simplex (Griessmann, 1913) Larsen & Patterson, 1990 (ref. ID; 4872 Protista Incertae sedis)

Descriptions

Cell obovate or tapering markedly to posterior (flagellated) end. Dorso-ventrally flattened, pellicle smooth or with small infrequent pustules (protrusions). Usually with open flagellum but occasionally with two flagella of unequal length arising from the posterior part. The dominant flagellum is twice as long as the cell or longer, and ends in a hook that is attached to substrate. The second flagellum when present emerges next to the first but can be difficult to see. The behaviour of the cell resembles a pendulum swinging with an arc of up to 110 degrees. Inflexion point at the attaching flagellum immediately above the hook. Cells normally attach to the substrate but may detach and glide with the cell body held up from the surface in an angle and the longer flagellum trailing along the surface. Gliding cell shake lightly from side to side. (ref. ID; 4872)

Remarks

Food ingestion takes place at the margins of cell (Patterson unpubl.) or through the anterior part of the cell (Griessmann 1913) but no mouth is visible. This species usually appears in large numbers after sediments have been kept for several days. This is consistent with their predatory nature. They may ingest other flagellates (Patterson, unpubl. obs). (ref. ID; 4872)

Measurements

Cell length 6.1 um, range 4-8.2 um. Size range 4-8 um reported by Larsen & Patterson (1990), Vors (1922). (ref. ID; 4872)