Micrasterias displays a bilateral symmetry, with two mirror image semi-cells joined by a narrow isthmus containing the nucleus of the organism.

The sugar created is used to provide energy for the organism or, if not used, taken up by many small round pyrenoids which are embedded in the chloroplast.

Sexual reproduction occurs through a process called conjugation whereby two organisms come together and fuse their haploid cells to form a diploid zygote.

This zygote typically forms a thick protective wall which can allow the organism to remain dormant for many months to survive cold winters and long droughts.

When adequate conditions resume, the zygospore will germinate, undergo meiosis, and produce new haploid algal cells.

[2] Micrasterias is generally easy to identify due to its shape and typically large size.

They have a similar morphology to the simpler species of Micrasterias, but molecular phylogenetic analyses show that they are not related.

[3] Freshwater microalgae, along with other microscopic organisms, are often presumed to be cosmopolitan in distribution (see the Baas Becking hypothesis).