Vorticella VS. Rhabdostyla
by Dan Holloway, USA
The fish pond is a good place to get water samples for a look under the microscope and a fascinating organism is the Vorticella. If you haven't observed this creature you are missing a wonderful sight. Dark field as well as bright field yield great images. Most Vorticella can be viewed at 100x or 200x with 200x showing a lot of detail.
While watching a group of Vorticella I noticed one attached to a stalk of vegetation. Upon closer examination I watched as the head recoiled from some external stimulus while the stalk remained rigid.
This was new to me. As usual, my curiosity got the best of me and I went online to find the difference between the rigid stalk and the contractile stalk. The website Protists was very helpful in this matter. It can be found here: http://protist.i.hosei.ac.jp/PDB/Images/menuE.html
It is a wonderful resource.
Below are the pictures of the differences.
More Rhabdostyla.
Now I know
the difference and so do you! 
All comments or questions welcome.
Published in the August 2010 edition of Micscape Magazine.
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