Most natural history blogs are about birds butterflies and occasionally snails. The other groups of organisms don’t get much publicity. So, to make up for that in a meager way and on occasion of the upcoming edition of the Animalcules, here is an old photo of some ciliates, or ciliated protozoa, or protists, or whatever you may prefer to call them. It is, of course, fitting that ciliates were among the original "animalcules". Their name comes from the fact that their bodies are covered with tiny hairs, or cilia.
This is one of the first photomicrographs I ever took. It was taken in February 1977 on black & white film using an old range finder camera positioned on a tripod above the eye piece of my microscope. Because I couldn’t see what the camera was actually seeing, it was a trial and error process and I didn’t, of course, know what was captured on the film until after I developed it. The vignette around the image was caused by the aperture blades. (How on earth did we survive without digital cameras?)
It shows what appears to be a Paramecium and many smaller ciliates, possibly belonging to a Colpoda species. It is interesting to note that these creatures, although about 150 years ago they were determined to be neither animals nor plants (by Richard Owen), are still treated together with invertebrate animals. Pick up any invertebrate textbook and you are very likely to find a chapter on protozoa.
A 1996 review1 estimated that there are about 3000 free-living species of ciliates. They are widespread and quite common. Gather some dry grass blades, leaves and other plant remains, put them in some water to create what is usually called a “hay infusion”, wait a few days and then you will have protozoans, including lots of ciliates. You will, of course, need a microscope to see them. And where do they come from? If you don’t believe in spontaneous generation, you have to start with the assumption that viable cysts are on the plants remains, in the water or fall from the air.
1. Finlay et al. 1996. Quarterly Review of Biology 71:221.