Desmid of the month
Std. cuspidatus is a triradiate Staurodesmus species characterized by a
highly elongate isthmus. The semicell body (above the isthmus) is about
triangular in outline. Length and projection of the spines are rather variable.
The globose zygospores are furnished with long spines arising from a conical
base. In the Netherlands Std. cuspidatus is a fairly common species in
mesotrophic, slightly acidic fen hollows and moorland pools where it
incidentally even may cause a bloom. Zygospores, on the contrary, have been
found only a few times.
Image © Marien van Westen ( mouse over )
Cell of Std. cuspidatus in both
frontal view (only partly in focus) and apical view (mouse over). Notice the elongate isthmus.
Cell dimensions (L x B, spines excluded):
ca 30 x 25 µm