Redescription of Dexiotricha colpidiopsis (Kahl, 1926) Jankowski, 1964 (Ciliophora, Oligohymenophorea) from a Hot Spring in Iceland with Identification Key for Dexiotricha species.

We isolated an encysted ciliate from a geothermal field in Iceland. The morphological features of this isolate fit the descriptions of Kahl, 1926) Jankowski, 1964 very well. These comprise body shape and size in vivo, the number of somatic kineties, and the positions of macronucleus and contractile vacuole. Using state-of-the-art taxonomic methods, the species is redescribed, including phylogenetic analyses of the small subunit ribosomal RNA (SSU rRNA) gene as molecular marker. In the phylogenetic analyses, clusters with the three available SSU rRNA gene sequences of congeners, suggesting a monophyly of the genus . Its closest relative in phylogenetic analyses is , which also shows a high morphological similarity. This is the first record of a species from a hot spring, indicating a wide temperature tolerance of this species at least in the encysted state. The new findings on are included in a briefly revision of the scuticociliate genus and an identification key to the species.