Hi

Two images of the common protozoan Vorticella are shown. Vorticella are bell-shaped with a long stalk which can contract. They are usually found attached to either water plants or sometimes to other animals like water fleas. The wide end of the 'bell' has cilia that create water currents which attract food like bacteria. 

The bell is about 0.1mm long but up to 1mm long with stalk. I found them tricky to photograph but the enclosed gives a feel for what they look like.

To find them, look along bits of water plant or algae at low mag. If you see tiny jelly-like blobs with a stalk, use a higher mag. to see what they are. 

If you find any, they are fascinating to watch. Individuals often grow together but they aren't attached to each other. Similar species like Carchesium are attached like the branches of a tree. The slightest knock of the slide will probably make the Vorticella contract, but be patient and the stalk will lengthen and cilia on the end of the 'bell' will unfurl to carry on feeding.

When watching them, see if you can spot the spiral dark thread along the length of the stalk. It is a muscle-like thread that contracts the stalk. It is just visible in the second image below.

Good hunting!

Dave Walker

Objective 10x. Lighting - phase contrast.
Two Vorticella showing the bell-shape and stalks. The cilia are in rapid motion so appear fuzzy.
[img]http://www.microscopy-uk.org.uk/dww/forum/vort2.jpg[/img]

Objective 20x. Lighting - phase contrast.
A close up of the 'bell' of a Vorticella.
[img]http://www.microscopy-uk.org.uk/dww/forum/vort1.jpg[/img]