I find Caenomorpha medusula in all my sampling locations with a sapropelic mud layer of decaying leaves. Caenomorpha medusula is easily recognized by its typical shape, which resembles a jellyfish. The rigid caudal spine can reach different lengths according to my observations and the body length was also quite variable. This metopid ciliate is a fast swimmer, but it can hold on to the substrate thigmotactically with the dorsally located cirri (s. fig. 5). The cirri are surprisingly long. On attached specimens one can observe how the activity of the adoral zone and the perizonal cilia generates a water current to capture food particles (mainly bacteria). The mouth opening is located approximately in the middle of the body at the level of the contractile vacuole. However, the cytopharynx is directed toward the anterior end (s. fig 4). The adoral zone begins dorsally, to the left of the two rows of thigmotactic cirri and completely encircles the body to the mouth opening. Here, the adoral membranelles lie in a furrow covered by the overhanging margin of the apical dome. The perizonal stripe runs parallel to the adoral zone onto the distal margin of the apical dome. At the base of the caudal spine a tuft of cilia is located (s. fig. 2b).