image © Henk Schulp
Micrasterias fimbriata. The large chloroplast in each of the semicells is provided with two distinct median, longitudinal ridges and a number of globose pyrenoids.
Cell dimensions (L x B): ca 240 x 220 µm
In the Netherlands Micrasterias fimbriata is a rare species, mainly to be encountered in mesotrophic quaking fen regions at the transition of Pleistocene and Holocene deposits. On a superficial view it somewhat resembles the more common species Micrasterias rotata but its habit is more delicate as lobules of the last order are denticulate in stead of emarginate. At the basal and apical semicell angles those denticulations are even transformed into curved spinules.
The herewith figured cell was met with in a Pleistocene moorland pool in 1999, a good ten years after which this pool had recovered from serious eutrophication (Coesel 1998).
image © Wim van Egmond
Dividing cell of Micrasterias fimbriata
Coesel, P., 1998. De sieralgenflora van De Banen: een nieuwe start (with abstract in English). Natuurhistorisch Maandblad 87: 214-218