| Zoochlorella | |
|---|---|
| Scientific classification (obsolete) | |
| Kingdom: | Plantae |
| Division: | Chlorophyta |
| Class: | Trebouxiophyceae |
| Order: | Chlorellales |
| Family: | Chlorellaceae |
| Genus: | Zoochlorella K.Brandt, 1881, nom. rejic. |
Zoochlorella (pl.: zoochlorellae) is a colloquial term for any green algae that lives symbiotically within the body of an aquatic invertebrate animal or a protozoan. [1]
Zoochlorellae are various genera belonging to the classes Chlorophyceae and Trebouxiophyceae, [1] historically treated as a single genus Zoochlorella due to their similar appearance to the genus Chlorella . [2] 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. [1]
The analogy between zoochlorellae and chloroplasts was used by the botanist Konstantin Mereschkowski in 1905 to argue about the symbiotic origin of chloroplasts (then called 'chromatophores', a term used for completely different structures today). [3]
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 .
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 . [1]