Desmid of the month
October 2021

Closterium attenuatum

Closterium attenuatumImage © Alfred van Geest

Closterium attenuatum. Notice large cell dimensions, slight curvature and abrupt attenuation at the poles.

Cell dimensions (L x B): 565 x 35 µm


Image © Alfred van Geest

Closterium attenuatum. Detail of attenuated cell end.

Cl. attenuatum is a large-sized, slightly curved Closterium species that somewhat resembles Cl. delpontei. Main difference is in the shape of the cell ends: in last-mentioned species cells gradually narrow towards the poles, in Cl. attenuating they abruptly attenuate at a short distance from the apex. Like in Cl. delpontei, cell wall is distincly striate and often yellow-brownish coloured. In the Netherlands, Closterium attenuatum is a rather rare species, predominantly known from mesotrophic quaking fen hollos.


Image © Alfred van Geest

Closterium attenuatum. Detail of mid region showing striation of cell wall.