''Vorticella convallaria'' is a species of

ciliate The ciliates are a group of alveolates characterized by the presence of hair-like organelles called cilia, which are identical in structure to flagellum, eukaryotic flagella, but are in general shorter and present in much larger numbers, with a ...

s. It is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

of the genus ''

Vorticella ''Vorticella'' is a genus of bell-shaped ciliates that have stalks to attach themselves to substrates. The stalks have contractile myonemes, allowing them to pull the cell body against substrates. The formation of the stalk happens after the fr ...

''. It resembles '' V. campanula'', but differs in being somewhat narrow in the anterior end and usually having no refractile granules in the

endoplasm Endoplasm generally refers to the inner (often granulated), dense part of a cell's cytoplasm. This is opposed to the ectoplasm which is the outer (non-granulated) layer of the cytoplasm, which is typically watery and immediately adjacent to the ...

. ''Vorticella convallaria'' exhibits two morphological types. The primary type is the sessile trophont stalked

zooid A zooid or zoöid is a single animal that is part of a colonial animal. This lifestyle has been adopted by animals from separate unrelated taxa. Zooids are multicellular; their structure is similar to that of other solitary animals. The zooi ...

. When environmental conditions deteriorate the stalked zooid excises its stalk and transforms into ''Vorticella's'' secondary type, the motile dispersive

telotroch Telotroch is the free-swimming stage of members of the order Sessilida. Sessilida are ciliates of the subclass Peritrichia. A sessile individual can turn into a motile one to migrate to a better place.μm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

long and 35-53 μm wide. The

peristome Peristome (from the Greek ''peri'', meaning 'around' or 'about', and ''stoma'', 'mouth') is an anatomical feature that surrounds an opening to an organ or structure. Some plants, fungi, and shelled gastropods have peristomes. In mosses In mosses, ...

ranges from 55-75 μm in diameter. The rod-like, contractile stalk - the "spasmoneme" - is 25-300 μm long and 4 μm wide. It can collapse into a tightly coiled

helix A helix () is a shape like a corkscrew or spiral staircase. It is a type of smooth space curve with tangent lines at a constant angle to a fixed axis. Helices are important in biology, as the DNA molecule is formed as two intertwined helices, ...

in less than 1/60th of a second. The contraction occurs when the negatively charged "spasmin" proteins that make up the spasmoneme are neutralized by binding with calcium, causing the stalk to collapse.Upadhyaya Lab
Measuring the contraction of a biological spring
/ref>

References

* PAUL J. DE BAUFER, AMR A. AMIN†, SAMANTHA C. PAK‡ andHOWARD E. BUHSE JR*. 1999.
Method for the Synchronous Induction of Large Numbers of Telotrochs in Vorticella convallaria by Monocalcium Phosphate at Low pH
Journal of Eukaryotic Microbiology Volume 46, Issue 1, pages 12–16, January 1999 * Maciejewski, J.J., E.J. Vacchiano, S.M. McCutcheon & H.E. Buhse, Jr. 1999
Cloning and Expression of a cDNA Encoding a ''Vorticella convallaria'' Spasmin: an EF-Hand Calcium-Binding Protein
''The Journal of Eukaryotic Microbiology'' 46(2): 165–173. *Sallaq, R., D.H. van Winkle & J. Cao 2003
Determination of velocity, acceleration,and forces in the contraction of ''Vorticella convallaria''
American Physical Society, Annual APS March Meeting 2003, March 3–7, 2003. Abstract #Y9.001 * Shiono, H. & Y. Naitoh 1997. ''Journal of Experimental Biology'' 200(16): 2249–2261. * Vacchiano, E., A. Dreisbach, D. Locascio, L. Castaneda, T. Vivian & H.E. Buhse, Jr. 1992
Morphogenetic Transitions and Cytoskeletal Elements of the Stalked Zooid and the Telotroch Stages in the Peritrich Ciliate ''Vorticella convallaria''
''The Journal of Eukaryotic Microbiology'' 39(1): 101–106. * Wibel, R., E.J. Vacchiano & H.E. Buhse, Jr. 1993
Ultrastructural Study of the Cortex and Membrane Skeleton of ''Vorticella convallaria'' (Ciliophora: Peritricha)
''Transactions of the American Microscopical Society'' 112(2): 107–120. * Paul J. De Baufer, Serhiy Pylawka, and Howard E. Buhse, Jr. 2000
Evidence for a Signal Transduction System Initiating Stalk Excision in Vorticella convallaria
Transactions of the Illinois State Academy of Science 93(2): 201-213

External links

Oligohymenophorea Species described in 1758 Taxa named by Carl Linnaeus {{ciliate-stub

References

Further reading

External links