[3] Closterium is a diverse genus consisting of solitary cells, each made of two identical halves called semicells.

The cell wall is transparent, but with age it may become dark brown due to accumulated iron and manganese compounds.

[8] Conjugation in the homothallic strain occurs mainly at low cell density and is regulated by an ortholog of a heterothallic sex-specific pheromone.

However, homothallic meiosis may be maintained in Closterium peracerosum as an adaptation for surviving under stressful conditions such as growth in nitrogen depleted media at low cell density.

A proposed adaptive benefit of meiosis is the promotion of homologous recombinational repair of DNA damages that can be caused by a stressful environment [9] Like other desmids, Closterium is found in freshwater habitats.

Closterium is usually attached to sediments or aquatic plants, but may sometimes be planktonic, i.e. free-floating in the water column, or found in wet soils.