Phylum: Charophyta   Family: Desmidiaceae

Cosmarium pseudoklebsii F.A.C. Kouwets 2025

This newly described species is a slightly smaller form of C. klebsii in outline form. A single cell from the Outer Hebrides mimics Kouwets’ dimensions very well.
Kouwets’ Cell dimensions: L: 27-28 µm, B: 26-28 µm, Is. 7-8 µm; Th. 12.5-13 µm L/B: 1.0-1.04.
Mine – single cell: L: 24.8 µm, B: 24.3 µm, Is. 7.7 µm; Th. 13.3 µm L/B: 1.02.
From a meso-oligotrophic vegetated loch-margin, slightly acidic.

References: 
Kouwets, F.A.C. (2025). European Flora of the Desmid Genus Cosmarium.