Phylum: Charophyta   Family: Gonatozygacea

Gonatozygon aculeatum W.N. Hastings 1892

Apices slightly swollen with two small granules visible in face-view. Spines are usually about 3 µm but can be longer, especially at the apices.
Cell dimensions: L: 90-250 µm; B: 6-12 µm; L/B: 10-28.
A rare species largely confined to the Atlantic north-west in Europe. Found in circumneutral to more acidic moorland pools, lochans and disused peat-cuttings.

References: 
Brook, A.J. & Williamson, D.B. (2010). A Monograph on some British Desmids.
Coesel, P.F.M. & Meesters, K.J. (2023 second edition). Desmids of the Lowlands.
Van Westen, M.C. (2024). Sieralgen in Drenthe.