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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Dinema

Dinema Perty, 1851 (ref. ID; 4950)

Euglenida Butschli, 1884 (ref. ID; 4872)
  1. Dinema inaequale Larsen & Patterson, 1990 (ref. ID; 4872)
  2. Dinema griseolum Perty (ref. ID; 3517, 4950)
  3. Dinema litorale Skuja, 1939 (ref. ID; 4872) reported year? (ref. ID; 4950)
  4. Dinema validum Larsen & Patterson, 1990 (ref. ID; 4872)

Dinema inaequale Larsen & Patterson, 1990 (ref. ID; 4872)

Descriptions

Cell length 30 um. Cell oval to slightly ovoid with anterior end bluntly pointed and posterior end rounded. Striation on the left ventral side, right ventral side smooth. Two flagella of unequal length, thickness close to equal. Anterior flagellum about cell length, held in front with the tip slightly curved, sweeping from side to side. Posterior flagellum 2 times cell length, emerging from a flagellar pocket on the left side of the cell. Ingestion organelle not observed. Elliptical nucleus on the right hand side in the middle of the cell. Cell gliding. (ref. ID; 4872)

Remarks

Larsen & Patterson (1990) reported cell length to be 26-30 um and posterior flagellum 1+1/2 times cell length, and this is well in agreement with the length reported here. No ingestion organelle observed although algal material could be seen inside, indicating that it was overlooked. The cell resembles D. valida to some extent in shape and length, but the latter has striations over the ventral as well as dorsal side. (ref. ID; 4872)

Dinema litorale Skuja, 1939 (ref. ID; 4872) reported year? (ref. ID; 4950)

Descriptions

Cell length 56 um, range 47.4-65 um. Cell spindle-shaped to ovate, with about 30 stripes running counter clockwise as a helix around the cell. Ingestion apparatus with two rods clearly visible on the right ventral side, extending halfway through the cell. Flagellar pocket difficult to see. Nucleus spherical, in the centre of the cell or slightly posterior. Anterior flagellum about cell length emerging from the same groove as the posterior flagellum. Posterior flagellum about 1+1/2-2 times cell length, base wide but narrowing towards the tip which is pointed. Cell moves by smooth gliding interrupted with sudden stops, jerks back while becoming more spherical and then continues gliding. There are refractile globules clustered around the ingestion apparatus. The right upper corner of the ingestion apparatus has a knob. (ref. ID; 4872)

Remarks

Length range reported to be 80-95 um (Skuja 1939), 60-75 um (Larsen 1987) and 40-72 um (Larsen & Patterson 1990). The posterior flagellum slightly longer than described by Skuja (1939) and Larsen & Patterson (1990), but our description is otherwise well in agreement with the original description. Nucleus not located posterior as indicated by Larsen & Patterson (1990), but similar to original drawing by Skuja (1939). Known to be able to feed osmotrophically and phagotrophically on diatoms (Huber-Pestalozzi 1955). (ref. ID; 4872)

Dinema validum Larsen & Patterson, 1990 (ref. ID; 4872)

Descriptions

Cell 30.5 um. Oblong with obtuse ends, both sides covered with 10-15 longitudinal striations which run slightly counter-clockwise following a helix. Spherical nucleus located in the posterior part of the cell. Ingestion apparatus visible, extending halfway down the cell. Anterior flagellum about cell length, posterior flagellum thick, emerging from the flagellar pocket in a hook, extending twice the cell length. Cell gliding, with a capacity to contract. (ref. ID; 4872)

Remarks

The end of the ingestion apparatus seems to be embedded in a rigid mass of cytoplasm. (ref. ID; 4872)