Image © Alfred van Geest
Closterium moniliferum. Notice lunate cell shape, broadly rounded, slightly recurved apices and axial row of pyrenoids.
Cell dimensions (L x B): 215 x 50 µm
Closterium moniliferum is marked by rather strongly arched, lunate cells. The ventral side of the midregion is usually inflated ('belly'), the cell ends are broadly rounded and often slightly recurved. At first glance, the cell wall seems to be smooth but at high magnification it appears delicately striate. The chloroplast contains an axial series of pyrenoids and is bordered by a terminal vacuole holding quite a number of quivering granules*. In the Netherlands, Closterium moniliferum is quite common in benthos and tychoplankton of meso-eutrophic, slightly acidic to alkaline water bodies.
* vacuolar granules in Closterium moniliferum have been analyzed to consist mainly of barium sulphate crystals http://dx.doi.org/10.1080/00071618000650251
Also strontium may be accumulated in those crystals and this feature could be applied to remove radioactive strontium-90 from the environment
Closterium mominiliferum. Detail of cell end with vacuole holding a lot of crystalline granules.
Closterium moniliferum. Detail of cell wall showing delicate striation.
An oligochaete worm with in its gut various algal species, among which the desmid Closterium moniliferum. See also 'Desmids in the food web'.