Phylum: Charophyta   Family: Desmidiaceae

Cosmarium esclauzense F.A.C. Kouwets 2025

A recently described very small desmid found in several lakes in France. Named after Lac de l'Esclauze, Auvergne, France. See Kouwets (2025) for similar species but this cell has a particularly narrow isthmus.
Single cell dimensions: L: 8.3 µm; B: 8.6 µm; Is: 2.3 µm; Th: 4.4 µm; L/B: 0.97.
Found at the margin of a shallow, stony, loch with circumneutral acidity.

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