Merismopedia glauca
(Ehrenberg) Nägeli, 1845
Most likely ID: n.a.
Synonym: n.a.
Sampling location: Simmelried
Phylogenetic tree: Merismopedia glauca
Diagnosis:
- colonies small with up to 64 cells
- cells spherical, ellipsoidal or hemispherical (after cell division), 3–6 µm
- mucilage sheat distinct, following conturs of cells
- content of cells homogeneous
- color blueish-green, often pale, sometimes pinkish
I found Merismopedia glauca in October 2003 in the Simmelried. After that I have not registered any more finds of this species.
Merismopedia glauca is very similar to Merismopedia elegans. However, the colonies of Merismopedia glauca are much smaller and contain maximum 64 cells. In contrast, the tabular colonies of Merismopedia elegans can contain up to 4000 cells. In addition, the mucus envelope around the cells of Merismopedia glauca is distinct and fits closely to the cells, whereas the mucus envelope surrounding the colonies of Merismopedia elegans has a distance of about one cell diameter from the outer cells.
The color of the cells of Merismopedia glauca is variously reported. It is said to be blueish-green and sometimes pinkish. The cells of my population were more olive green.
Fig. 1: Merismopedia glauca. Some colonies with 8 – 16 cells embedded in a field of yellowish sulfur bacteria. Obj. 40 X.
Fig. 2: Merismopedia glauca. A colony of 16 cells in detail. Each cell (in cell division) has a length of about 10 µm (= 5 µm per half-cell). Note the distinct mucilaneous sheat (MS) following the conturs of the cells. Obj. 100 X.