Zoochlorella (: zoochlorellae) is a colloquial term for any green algae that lives symbiotically within the body of an aquatic invertebrate animal or a protozoan. However, this genus was found to be polyphyletic through molecular phylogeny, and currently considered nomen rejiciendum. As a consequence, the two species belonging to this obsolete genus have been transferred to different green algal genera.
Occurrence
In animals
thumb|[[Anthopleura xanthogrammica gains its green colour from Zoochlorella]]
Zoochlorellae are responsible for the greenish colour of sea anemone tentacles. Zoochlorellae and zooxanthellae may both be found in the Pacific coast sea anemones Anthopleura elegantissima and Anthopleura xanthogrammica.
In protists
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.
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