So far I have only found a single specimen of Ophryoglena utriculariae in floating plants in the Simmelried. However, both Song & Wilbert (1989) and Kahl (1931) describe the species as common and widespread. Kahl mentions that he found Ophryoglena utriculariae exclusively among Utricularia.

The specimen I found was only 85 µm long, much smaller than the average length of 120–220 µm. However, both Kahl and Song & Wilbert mention that dwarf forms do occur.

The characteristics of my specimen match the descriptions for Ophryoglena utriculariae. I could not yet recognize the caudal cilia in the freely swimming specimen, but only in the slightly squashed specimen (s. fig. 3 a). The body is somewhat pointed apically, as described by Kahl (s. fig. 2 c). There is only one contractile vacuole, which is located dorsally and approximately in the middle of the body. I could recognize 4 excretory pores of the contractile vacuole (s. fig. 4).

The macronucleus is elongated ellipsoid with a rather large, attached micronucleus (s. fig. 5). A clear fringe of rod-shaped extrusomes can be seen under the pellicle, all of which are directed posteriorly (s. figs. 5 and 6). According to my measurements they are about 3.3 µm long (s. fig. 6). This agrees well with the data of Song & Wilbert (3.8 µm). As in all Ophryoglena species, the oral apparatus is shaped like a 6. On the left wall of the vestibule is the watch-glass body located, which is also called Lieberkuehn’s organelle (s. figs. 3 b and 7). This organelle is well developed and clearly recognizable in Ophryoglena utriculariae. Its function is unclear, but it is assumed that it is connected with the widening of the mouth opening when swallowing large prey.