Distribution and ecology


Probably found everywhere in the world where the conditions are suitable for it.


Cercomonas clavideferens is abundant in soils and freshwater sediments, but has not been found alive in the sea.

There are probably millions of these organisms in every kilogram of soil.


Cercomonas species are thought to be among the commonest protozoans, eating bacteria in 

  • soils 
  • freshwater habitats. 

Cercomonas species are likely to be extremely important in microbial food webs, on which all other life depends.

The more we find out about the number of different species of these organisms, and exactly what their ecological roles are, the more we will understand how different environments ‘work’. For example, interactions involving organisms like Cercomonas might help us to understand why some soils are better for some plant species than others.


Cercomonas clavideferens is a voracious predator of bacteria, but probably eats a much wider range of organisms.

Some Cercomonas species are known to gang up on and kill nematode worms, many times their size.