Cell of Cosmarium commissurale in frontal view. Notice reniform semicells with slender, incurved lateral lobes.

Cell dimensions (L x B): 30 x 45 µm



Desmid of the month
July 2021

Cosmarium commissurale

C. commissurale somewhat resembles C. ornatum but semicells are more reniform, cell sinus is open instead of largely closed, and lateral semicell lobes are more slender. In the Netherlands, C. commissurale is a rather rare species in various mesotrophic water bodies.

Mouse over images © Alfred van Geest

Empty cell of C. commissurale. Notice cell wall ornamentation: concentric series of granules in semicell centre separated from series of granules in the lateral lobes by a wide, unsculptured zone.

Cell of C. commissurale in apical view. Notice strong median inflation of semicell.