Aplanochytrium
The genus Aplanochytrium is part of the class Labyrinthulomycetes. It is a sister genus of Labyrinthula and thraustochytrids. The major characteristic of all three genera is the production of an extension of the plasma membrane and the ectoplasm called the ectoplasmic net, but its use is different in each genera. Aplanochytrium cells are not embedded in the ectoplasmic net but can move by gliding on the ectoplasmic threads. Cells of the genus Aplanochytrium multiply by forming aplanospores in a spherical sporangium. The spores are then released and they move away by crawling along their own ectoplasmic thread. The aplanospores are non-flagellated asexual spores. Aplanochytrium is found exclusively in marine environments and lives on diverse host organisms. The symbiosis between Aplanochytrium cells and the host organism can be of various origins, like commensal or parasite. Etymology The genus Aplanochytrium was identified as a member of the Labyrinthulomycetes because of the formation of non-flagellated and thus non-motile spores, which Bahnweg & Sparrow named "aplanospores". These specific spores formed the base of the name of the genus. History of knowledge The genus Aplanochytrium was first described in 1972 by Bahnweg. First included in the order thraustochytrids, Aplanochytrium is now considered a sister group