Vorticella

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Vorticella
Scientific classification
Domain: Eukaryota
Kingdom: Chromalveolata
Superphylum: Alveolata
Phylum: Ciliophora
Class: Oligohymenophorea
Subclass: Peritrichia
Order: Sessilida
Family: Vorticellidae
Genus: Vorticella
L. (1767)
Species

See text

Vorticella is a genus of protozoa, with over 16 known species. They are stalked, inverted bell-shaped ciliates, placed among the peritrichs. Each cell has a separate stalk anchored onto the substrate, which contains a contractile fibril called a myoneme. When stimulated, this shortens, causing the stalk to coil like a spring. Vorticella species mainly live in freshwater ponds and streams—generally anywhere protists are plentiful.

Reproduction is by budding, where the cell undergoes longitudinal fission and only one daughter keeps the stalk. The free daughter becomes a telotroch, which swims until it finds suitable substrate to fix and develop its own stalk. They reproduce by fission, which is also known as cell division. They are also capable of reproducing by conjugation, a form of sexual reproduction where two individuals attach at the oral groove and exchange DNA.

Other genera, such as Carchesium, resemble Vorticella, but are branched or colonial.

Vorticella species sometimes stay in clusters or groups considered as colonies, but they are not true colonies because each cell has its own individual stalk. This allows it to detach from the cluster at any time, usually by reverting to a telotroch when environmental conditions are unfavorable.

Common species[edit]


Sequence showing the activation of Vorticella spring and recovery
A telotroch, recently fixed to the substrate, grows its stalk and becomes a vorticella
Vorticella reproducing by cell division
Vorticella under microscope (40x)
Movies of Vorticella contracting and extending - left: Vorticella campanula, right: probably Vorticella convallaria at higher magnification (for full resolution click first on image)