Desmodesmus opoliensis var. carinatus

(Lemmermann) E. Hegewald, 2000

Most likely ID: n.a.

 

Synonym: Scendesmus opoliensis var. carinatus

 

Sampling location: Pond of the waste disposal company Constance

 

Phylogenetic tree: Desmodesmus opoliensis var. carinatus

 

Diagnosis: 

  • linear coenobia of 2–4 cells (rarely 8)
    all cells arranged parallel
  • cells 8–21 long, width 2.5–8 µm
  • cells slender ellipsoid with slightly tapered ends
  • apices of inner cells with several small spines
  • apices of outer cells with long spines
  • lateral surfaces of cells with distinct ribs, often doubled
  • one pyrenoid per cell
Desmodesmus-opoliensis-var-carinatus
Desmodesmus opoliensis var. carinatus

I find Desmodesmus opoliensis var. carinatus more frequently in the plankton of the pond of the waste disposal company Constance. This pond is heavily eutrophied and stocked with fish. So far I have found the species only in this pond.

 

The cells of Desmodesmus opoliensis var. carinatus are aligned parallel to each other and not as in the nominate form Desmodesmus opoliensis, in which the two middle cells are always arranged obliquely. Another important characteristic is the clearly visible ribs that run over the sides of the cells. They can be single, but also double, as in the specimen shown below (s. fig. 1 a-b). All other characteristics agree with the description by Komarek & Fott (1983).

Desmodesmus-opoliensis-var-carinatus

Fig. 1 a-b: Desmodesmus opoliensis var. carinatus. L = 23 µm (of coenobium). Two focal planes of a specimen found in September 2025 in the plankton of the pond of the waste disposal company Constance. On the lateral surfaces of cells double ribs are visible (b). Obj. 100 X.