Image © Koos Meesters
Closterium lineatum. Notice cell outline: about linear for the greater part, only near the poles curving and attenuating to the truncately rounded apices.
Cell dimensions (L x B): 510 x 16 µm
Closterium lineatum is closely affiliated to Cl. delpontei. The main difference is in the cell outline: about fusiform in Cl. delpontei, for the most part linear in Cl. lineatum. Just like in Cl. delpontei, cell wall in Cl. lineatum is finely but distinctly striate and conjugation results in the formation of urn-shaped twin zygospores. In the Netherlands, Cl. lineatum is occasionally encountered in slightly acidic mesotrophic fen hollows and moorland pools. Zygospores are found but a few times.
Image © Marien van Westen
Twin zygospore of Closterium lineatum. Notice urn-shaped spores and striation of cell wall in the empty gametangial cells.