Chilomonas are free-living, freshwater protozoans. They inhabit water littered with decaying plant matter like stagnant ponds, ditches or marshes. These protozoans are unable to photosynthesize because they lack chloroplasts, or chromatophores, which are pigment containing structures. They commonly feed on organic matter and are often consumed by other protists such as Amoeba
and Paramecia. Chilomonas are extremely tiny, usually reaching 20–24 microns in length, which is below the limits of visibility to the naked eye. Two flagella extend from their anterior giving the Chilomonas excellent locomotion.