Centritractus dubius (Printz, 1914)

Most likely ID: n.a.


Synonym: n.a.


Sampling location: Simmelried


Phylogenetic tree: Centritractus dubius



  • cells solitary, short ellipsoidal or cylindrical
  • both ends rounded with coarse spines
  • length of cell without spines 10–14 µm, width 5–6 µm
  • cell wall in the middle thin for reproduction
  • 2–3 chromatophores
  • length of spines about width of cell
Centritractus dubius

The tiny alga Centritractus dubius belongs to the yellow-green algae (Xanthophyceae). I have found Centritractus dubius so far only in the Simmelried. In the samples Centritractus dubius is hard to find due to the small size. However, it often colonizes floating coverslips where it can easily observed. I observed that the older cells are often surrounded by a layer of iron precipitate and then appear reddish to brownish (s. fig. 2). Centritractus dubius has so far only been found in Norway. Further findings are not known. This may be because it is difficult to find among detritus and decomposing plant material. Possibly there would be more detections of this yellow-green alga by floating coverslips on the samples where it is easier to detect.


Fig. 1: Centritractus dubius. L = 12 µm (with spines 27 µm). Obj. 100 X.

Fig. 2: Centritractus dubius. L = 12 µm (with spines 22 µm). A second specimen slightly covered with iron precipitation. Obj. 100 X.