Zoothamnium

Zoothamnium is a genus of ciliate protozoan.

==History== Zoothamnium was initially classified as a member of the family Vorticellidae by Ehrenberg in 1838. It was later reclassified to the family Zoothaminiidae, a new family defined by Sommer, in 1951. The unique ability of the central stalk to contract in a zig-zag pattern made the reclassification a necessity. Zoothamnium is a sessile peritrich, meaning it is a ciliated vase shaped protozoan that is nonmotile in nature. The genus comprises more than seventy species. Differentiation between species can often be difficult due to the strong similarities in form and function. The most commonly cited species are as follows: Zoothamnium alternans Zoothamnium arbuscula Zoothamnium arcuatum Zoothamnium bucciniiformum Zoothamnium duplicatum Zoothamnium florens Zoothamnium grossi Zoothamnium hentscheli Zoothamnium ignavum Zoothamnium intermedium Zoothamnium maximum Zoothamnium mucedo Zoothamnium nii Zoothamnium niveum Zoothamnium paraentzii Zoothamnium parahentscheli Zoothamnium parahiketes Zoothamnium pararbuscula Zoothamnium pelagicum Zoothamnium pluma Zoothamnium plumula Zoothamnium wangi Zoothamnium zhanjiangense