Apsiktrata gracilis is the most common prostomatid ciliate in the mud of Simmelried. It is present in almost all samples, sometimes in masses. The species can be easily identified by the thickened ends of the trichites of the basket, which together form an apikal, refractive collar (s. fig. 3). The basket of trichtites is often oblique relative to the longitudinal cell axis, which can be easily seen in freely swimming and spinning specimens. In addition, this ciliate has a rather long caudal cilium. In my population, all of the specimens I examined were filled with clearly visible symbiotic bacteria. Interestingly, these are not mentioned by any of the earlier authors, including Foissner, who published an accurate redescription in 1984 (still under Holophrya gracilis). Originally this species was described as Urotricha gracilis by Penard. Later Kahl placed it in Holophrya. Finally, Foissner, Berger and Kohmann transferred this species from the genus Holophrya to the newly created genus Apsiktrata, because in contrast to Holophrya and Prorodon species of the genus Apsiktrata do not possess a dorsal brush.