Closterium navicula
(Brébisson) Lütkemüller, 1905
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Schwemm Moor (Austria)
Phylogenetic tree: Closterium navicula
Diagnosis:
- cell straight, spindle-shaped or boat-shaped apices
- length 25–50 µm, width 10–15 µm
- cell wall smooth, colorless
- two chloroplasts with 3–5 longitudinal ridges
- one pyrenoid per semi-cell
- girdle bands absent
- terminal vacuoles with single or few small crystals
So far, I have only found Closterium navicula in the Schwemm Moor in Austria. However, only very few specimens were found in the samples.
Closterium navicula is one of the smallest species of the genus. Due to its spindle-shaped form and small size, it is not immediately recognizable as a Closterium species, as most other species are distinctly curved. Upon closer inspection, however, the two terminal vacuoles typical of Closterium can be seen. The chloroplasts show distinct longitudinal ridges, as found in most other Closterium species.
Fig. 1 a-b: Closterium navicula. L = 34 µm. Two focal planes of a specimen in DIC. Obj. 100 X.
Fig. 2 a-b: Closterium navicula. L = 34 µm. The same specimen as shown in fig. 1 a-b in brightfield illumination. Obj. 100 X.