Cosmarium microsphinctum
Image © Alfred van Geest

Cosmarium microsphinctum. Cell of Cosmarium microsphinctum in frontal view. Notice pyramidal outline of semicells and relatively broad cell isthmus.
Cell dimensions (L x B): 40 x 27 µm

Cosmarium microsphinctum

Image © Alfred van Geest

Cell of Cosmarium microsphinctum in apical view. Notice somewhat rhomboid shape of semicell.

 


Desmid of the month
May 2023

Cosmarium microsphinctum


C. microsphinctum somewhat resembles C. cataractarum (desmid of January 2016). Cells have comparable dimensions, semicells are pyramidal in outline and the cell wall is remarkably punctate. Main difference is in the relative breadth of the cell isthmus: less than half the semicell breadth in C. cataractarum, more than half the semicell breadth in C. microsphinctum. In the Netherlands, C. microsphinctum was supposed to be rare but in recent years it is increasingly often encountered in ephemeral puddles on sandy soil.



Cosmarium microsphinctum

Image © Koos Meesters

Cell of C. microsphinctum (in oblique position) showing coarse punctation of cell wall.