Tribonema viride Pascher, 1925
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Suploch (Island Hiddensee)
Phylogenetic tree: Tribonema viride
Diagnosis:
- filaments straight of cylindrical cells, sometimes barrel-shaped
- cells 6–15 µm wide, 2–8 time longer than wide
- numerous chloroplasts per cell, irregular shaped discs
- cell wall smooth, crosswalls sometimes slightly constricted
Tribonema viride is one of the most common species of the genus. However, I have only recorded it once in the Suploch pond on the island Hiddensee. However, I have probably often overlooked it before because the thickness of the filaments has to be measured for identification and the shape and number of chloroplasts is decisive. The filaments of Tribonema viride are usually 10-11 µm wide and each cell contains many chloroplasts, which are irregularly shaped and attached to the cell wall (parietal). The cells are usually cylindrical and or slightly barrel-shaped. There are only very slight constrictions on the transverse walls. The other species within the genus Tribonema all have much thinner filaments.
Fig. 1: Tribonema viride. A bundle of filaments. Obj. 40 X.
Fig. 2 a-b: Tribonema viride. L = 30–40 µm (of cells). Two focal planes of a part of a 12 µm wide filament. Note the numerous chloroplasts (Chl) and the nucleus (Nu) located in the center of the cell. Obj. 100 X.
Fig. 3 a-b: Tribonema viride. L = 20–40 µm (of cells). Two focal planes of the cells in a second, 11 µm wide filament. Chl = chloroplasts, Nu = nucleus. Obj. 100 X.
Fig. 4 a-b: Tribonema viride. L = 30–40 µm (of cells). The cells of a third filament in brightfield illumination. Obj. 100 X.