Cosmarium contractum O.Kirchner 1878

Division     Charophyta
Class     Zygnematophyceae
Order     Desmidiales
Family    Desmidiaceae
SynonymCosmarium jacobsenii Roy 1884; Cosmarium contractum f. (jacobsenii Roy) West & G.S. West 1902

    Cells medium in size, mostly cells longer than broad, cells deeply constricted at median and widely open sinus. Cells measure 39-44 μm in length and 25-29 μm in width, isthmus 5-8 μm broad. Semicell broadly oblong to circular in shape, mostly rounded apex or slightly truncated; cells circular in lateral view, oval shaped in vertical view. Cells walls are compactly punctuated.


Thalli collected as plankton from Lake and Ponds and it prefers slightly acidic and oligo-mesotrophic water bodies.

Distribution in India

Chhattisgarh, Gujarat, Jammu and Kashmir, Maharashtra, Meghalaya, Tamil Nadu and Uttarkhand.