Desmid of the month
September 2007

Netrium interruptum

Netrium interruptum may readily distinguished from Netrium digitus (desmid of the month of December 2003) by its cylindric cells that abruptly taper to the truncate poles. In addition to that, each cell contains four chloroplasts provided with entire, longitudinal ridges. Whereas Netrium digitus is commonly occurring in all kinds of shallow, acidic, oligo-mesotrophic water bodies, Netrium interruptum is much more rare. In the Netherlands it is only known from some mesotrophic quaking fens at the transition of Pleistocene to Holocene deposits.

Image © Henri Schlötz

Cell of Netrium interruptum with four chloroplasts. Notice the big, globular terminal vacuoles.

Cell dimensions (L x B): ca 250 x 50 µm


 

Picture of a cell of Netrium interruptum focussed on the longitudinal chloroplast ridges that are not notched (like in Netrium digitus) but entire.

 

 

 

Image © Wim van Egmond

 
 

Another cell of Netrium interruptum (among other algae, protozoa and purple sulfur bacteria). Notice the central nucleus as well as the terminal vavuoles that contain one single crystal each.

 

Image © Marien van Westen