I find Vasicola ciliata very frequently in my sampling sites. The species is anaerobic and lives in the deeper mud layers. The populations vary greatly, as they also correlate with the presence of purple bacteria, on which Vasicola ciliata mainly feeds. As a result, the specimens are always strongly pink-colored and opaque.

Vasicola ciliata builds its own lorica in which the ciliate lives and draws in food. The lorica is a swollen tube with a narrowed, apical opening. The middle part of the lorica has transverse ridges, which appear as a wave pattern in optical section. The lorica is usually attached to detritus flakes. It is thin-walled, transparent, and colorless. The ciliate inside the lorica usually takes on a broadly ellipsoid shape, and the somatic cilia grip the transverse ridges, providing it with support (s. figs. 2 and 3).

In the samples, one often also finds freely swimming specimens because Vasicola ciliata quickly leaves the lorica when disturbed. This is especially the case after placing the coverslip. In the freely swimming specimens, the caudal cilia can be seen quite well (s. fig. 7 a), which are difficult to recognize inside the lorica.

The pellicle of Vasicola ciliata shows a typical and very regular, rectangular pattern (s. figs. 7 b, 8 and 9). It connects the rows of somatic cilia, which are distributed in straight transverse rows over the body (s. fig. 10 a). In the front part of the body, an alveolar system of canals can also be seen under the pellicle (s. fig. 10 b). However, I could not recognize these canals in all specimens.