Tetmemorus brebissonii

(Ralfs ex Ralfs, 1848)

Most likely ID: n.a.


Synonym: n.a.


Sampling location: Postalm (Austria), Sima Moor (Austria)


Phylogenetic tree: Tetmemorus brebissonii



  • cells almost cylindrical
  • lateral margins slightly concave
  • length (95)–100–240–(264) µm
  • apices with a deep notch
  • cell wall with longitudinal rows of pores
  • one stelloid chloroplast per semi-cell with 5–6 longitudinal ribs
  • 2–5 pyrenoids per chloroplast
Tetmemorus brebissonii

I found Tetmemorus brebissonii in May 1997 in a pond on the Postalm (Austria) and again in July 1997 in the Sima Moor (Austria).


The cells of the genus Tetmemorus have a characteristic notch at the apices (s. fig. 1 a). The half-cells of Tetmemorus brebissonii are almost cylindrical with broadly rounded apices. In addition, longitudinal rows of pores covering the cell wall (s. fig. 1 b). In the smaller species Tetmemorus laevis these pores are absent and the cells are elongated oval.


Fig. 1 a-b: Tetmemorus brebissonii. L = 116 µm. Two focal planes of a specimen found in July 2017 in the Sima Moor (Austria). Note the apical invaginations (AI) and the longitudinal rows of pores (LP) covering the cell wall. Obj. 100 X.