Desmid of the month
June 2006

Cylindrocystis brebissonii

As indicated by its name, the saccoderm genus Cylindrocystis is marked by cylindric cells. It differs from the likewise cylindrically shaped genus Mesotaenium in that the chloroplast is not plate-like but asteroid (provided with radiating ridges). By far the most common species is Cylindrocystis brebissonii. The star-like chloroplast configuration is particularly well visible in relatively short cells. Chloroplasts of more elongate cells are often rather disorderly.

Cylindrocystis brebissonii is a most common species in acidic, oligotrophic, benthic habitats (particularly in Sphagnum vegetation) and is relatively often encountered in conjugating condition.

Some four cells of Cylindrocystis brebissonii. Notice its asteroid (star-like) chloroplast with ribbons that radiate from a central core (incorporating a pyrenoid).

Cell dimensions (L x B): 30-40 x 20 µm



Elongate cells (right) next to young, thick-set cells (left).


Two zygospores of Cylindrocystis brebissonii, the upper one in frontal view, the lower one in lateral view.