So far, I have found Engelmaniella mobilis exclusively in the Simmelried, where the ciliate is very rare. I have only found it twice, in November 2016 and November 2020. In total, however, there were only 3 specimens.

At low magnification, the slender, vermicular body of Engelmaniella mobilis resembles some slender representatives of the genus Chaenea. At medium magnification, however, the adoral zone is clearly visible, which accounts for only 10-15% of the body length (s. fig. 2 a). For a hypotrich ciliate, the ciliation is greatly reduced. Widely spaced cirri are distributed over the body, but they are thin and soft. Transverse and caudal cirri are completely absent. Only at the front end are three distinct frontal cirri present (s. fig. 3 d). The macronucleus consists of several nodules that lie along the longitudinal axis in the body. The contractile vacuole is located in the middle of the body.

The few specimens of my population were between 105–256 µm long. The body length of Engelmaniella mobilis seems to be very variable, ranging from 94–283 µm, and has been measured by various authors in 7 different populations. The average across all populations is 125 µm body length. The nodules of the macronucleus were difficult to see in all specimens of my population because the specimens were densely filled with highly refractive granules (s. figs. 1 b and 4). The contractile vacuole was located in the middle of the body in all specimens (s. figs. 1 d and 2 d). I could not recognize any rows of midventral cirri on the ventral side, as would be typical for the related genus Uroleptus. I could not detect any rows of cortical granules on my specimens, as mentioned by Berger (2011). Otherwise, all features corresponded to those of Engelmaniella mobilis.