Cyanothece major

(Schröter) Komárek, 1976

Most likely ID: n.a.

 

Synonym: Synechococcus major

 

Sampling location: Sima Moor (Austria)

 

Phylogenetic tree: Cyanothece major

 

Diagnosis: 

  • cells solitary, widely oval
  • with structureless layer of mucilage
  • length 30–70 µm, width 28–52 µm
  • color blue-green
  • granulated content
Cyanothece-major
Cyanothece major

I have only ever found Cyanothece major in the Sima Moor in Austria. The cells are immediately noticeable in the samples due to their size and intense coloration. The cells are always single, except during cell division. The cells are surrounded by an unlayered and not sharply delimited mucus envelope. The cells in my population were mostly broadly oval, ovoid or oblong. The cytoplasm appeared mostly vacuolated with numerous oil-like droplets.

 

Cyanothece major differs from the similar species Cyanothece aeruginosa essentially only in size. The cells of Cyanothece aeruginosa are said to be 10–50 µm long. So there are overlaps between the species. However, as the cells in my population were often over 60 µm long, it must be Cyanothece major.

Cyanothece-major

Fig. 1: Cyanothece major. L = 47–75 µm. Several specimens in brightfield illumination. Three of them during cell division. Obj. 40 X.

Cyanothece-major

Fig. 2 a-b: Cyanothece major. L = 52 µm. Two focal planes of a specimen in brightfield illumination. Obj. 100 X.

Cyanothece-major

Fig. 3 a-b: Cyanothece major. L = 52 µm. The same specimen as shown in fig. 2 a-b in DIC. Obj. 100 X.

Cyanothece-major

Fig. 4 a-b: Cyanothece major. L = 73 µm. Two focal planes of a specimen in cell division. Obj. 100 X.

Cyanothece-major

Fig. 5 a-b: Cyanothece major. L = 73 µm. The same specimen as shown in fig. 4 a-b in DIC. Obj. 100 X.

Download PDF