Image © Koos Meesters
Spirotaenia condensata. The chloroplast tape (here closely twisted) shows a series of globular pyrenoids.
Cell dimensions (L xB) ca 250 x 20 µm
The genus Spirotaenia belonging to the family of Mesotaeniaceae (saccoderm desmids) is characterized by a spiralling, parietal chloroplast (just like in the well-known filamentous alga Spirogyra). The most familiar species of this genus is S. condensata, marked by large, cylindric cells. Usually, the helical chloroplast is twisted tightly but cells with loosely twisted chloroplast tapes may be encountered as well. In the Netherlands, S. condensata is locally not rare, particularly in benthos of mesotrophic, slightly acidic habitats.
Close-up of daughter cells (mouse-over picture showing two different planes of focussing)
Image © Wim van Egmond
Just divided cell of Spirotaenia condensata