Pleurotaenium trabecula

The genus Pleurotaenium is characterized by elongate cylindric cells (circular in top view) which usually are but slightly constricted in the middle (so with a shallow sinus). The chloroplast is in the form of longitudinal, parietal bands, leaving space to a big, globular vacuole at the cell apex.

In the Netherlands, by far the most common species is Pleurotaenium trabecula, to be encountered in various kinds of meso-eutrophic water bodies, ranging from slightly acidic to slightly alkaline. Pl. trabecula is marked by a completely smooth cell wall and by semicells that use to be a bit swollen in the midregion.

Image on the left:

Detail of young semicells of a recently divided mother cell exhibiting big terminal vacuoles and crumpled parts of stripped-off primary cell walls (see webpage ‘Shedding of the primary cell wall’).