[4] Recent molecular analysis, however, indicates that the genus Pseudococcomyxa is contained within different Coccomyxa clades, signaling the fact that the two genera are the same.

Coccomyxa species are relatively small in size, measuring at about 6-14 by 3-6 μm and green in colour due to the presence of chlorophyll a and b.

[5] Coccomyxa are haplontic, meaning they spend a majority of their life cycles as haploids, and generally reproduce asexually.

They can be dominant in certain ecosystems and display an impressive diversity in habitat, possessing lifestyles that range from free-living to parasitic.

Coccomyxa has been recorded free-living in terrestrial biofilms, as soil algae, connected with mosses, planktonic in limnic ecosystems, in symbiotic associations with fungi and higher plants, and parasitic to marine mussels.

The aggregations of the green algae occur in the mantle, gill filaments, adductor muscle, visceral mass, and haemolymph of the species M.