Phylum: Charophyta   Family: Desmidiaceae

Cosmarium scenedesmus G.B. Delponte 1877

A characteristic species with reniform semicells and broadly rounded sides and apices. The main confusion species is Staurodesmus convergens before the spines have developed.
Cell dimensions: L: 36-44 µm, B: 37-45 µm, Is. 11-13 µm; Th. 19-20 µm L/B: 0.95-1.03.
Frequently found in circumneutral waters such as lochs, moorland pools and abandoned peat-cuttings.

References: 
Kouwets, F.A.C. (2025). European Flora of the Desmid Genus Cosmarium. Part 1: Text. Part 2: Plates.
Van Westen, M.C. (2024). Sieralgen in Drenthe.