Cosmarium pseudoconnatum in frontal view. Notice very shallow sinus.
Cell dimensions (L x B): 46 x 36 µm

C. pseudoconnatum in apical view. Notice furcoid chloroplast holding some four pyrenoids.



Desmid of the month
September 2018

Cosmarium pseudoconnatum

Cosmarium pseudoconnatum differs from C. connatum (desmid of last month) by smaller cell dimensions,  an even shallower sinus and the occurrence of some four pyrenoids in each chloroplast (versus two in C. connatum). The species under discussion somewhat resembles given representatives of the genus Actinotaenium. However, C. pseudoconnatum is marked by a furcoid chloroplast (with furcate lateral lobes) whereas Actinotaenium species are characterized by stelloid or asteroid chloroplasts. In the Netherlands, C. pseudoconnatum is a rare species in oligotrophic moorland pools.

Empty, disrupted cell of C. pseudoconnatum showing cell wall pore fields.