Tetmemorus brebissonii
Meneghini ex Ralfs, 1848
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Sima Moor (Austria), Ibmer Moor (Austria)
Phylogenetic tree: Tetmemorus brebissonii
Diagnosis:
- cells cylindrical or subcylindrical, tapering slightly to apices
- in transversal section circular
- apices truncate with deep incision
- length 100–240 µm
- chloroplasts stellate with 5-6 longitudinal ridges
- 3–5 pyrenoids per semi-cell
- cell wall covered with longitudinal rows of pores
So far I have only found Tetmemorus brebissonii in Austrian moors. The species is extremely common in the Ibmer Moor as well as in the Sima Moor.
The genus Tetmemorus can easily be recognized by the apical incisions, whereby the cells are round in transverse section. The genus Euastrum also has apical incisions, but the cells are flattened.
Characteristic of Tetmemorus brebissonii is the almost cylindrical, elongated cell shape and the longitudinal rows of pores that can be seen on the cell surface of the semi-cells (s. fig. 1 c).
Fig. 1 a-c: Tetmemorus brebissonii. L = 115 µm. Three focal planes of a slightly squashed specimen. Note the longitudinal rows of pores (LRP) covering the cell wall. Obj. 100 X.
Fig. 2 a-c: Tetmemorus brebissonii. L = 115 µm. The same specimen as shwon in fig. 1 a-c in brightfield illumination. Obj. 100 X.
Fig. 3 a-b: Tetmemorus brebissonii. L = 115 µm. Two focal planes of a second specimen. AI = apical incision, LP = longitudinal rows of pores. Obj. 100 X.