: zoochlorellae) is a colloquial term for any green algae that lives symbiotically within the body of an aquatic invertebrate animal or a protozoan.

As a consequence, the two species belonging to this obsolete genus have been transferred to different green algal genera.

Four species of distantly related testate amoebae have independently evolved into obligate mixotrophy through the acquisition of zoochlorellae: Hyalosphenia papilio and Heleopera sphagni, two lobose amoebae belonging to the order Arcellinida within the phylum Amoebozoa; Archerella flavum, a member of the Labyrinthulomycetes in Stramenopiles; and Placocista spinosa, a filose amoeba belonging to the order Euglyphida within the phylum Cercozoa.

[4] Various ciliates present zoochlorellae, such as the genera Paramecium, Stentor, Climacostomum, Coleps and Euplotes.

[1] In the centrohelid Acanthocystis turfacea lives a unique zoochlorella species known as Chlorella heliozoae.