Morphological, ontogenetic, and molecular investigations of freshwater hypotrich ciliates from China revealed a new genus Heterodeviata gen. nov. (Protista: Ciliophora), and a novel limnetic population of Deviata multilineae

Abstract Hypotrichs are among the most complex and highly differentiated ciliate lineages, which are distributed in diverse habitats. Members of the family Deviatidae Foissner, 2016 are commonly found in freshwater or low-salinity habitats, as well as soils. During a study of freshwater wetland diversity in China, a novel deviatid ciliate Heterodeviata sinica gen. nov. et sp. nov. and a distinct population of Deviata multilineae Zhang et al., 2022 were investigated based on morphology, morphogenesis, and 18S rRNA gene sequences. The new genus Heterodeviata gen. nov. can be characterized by having two or more left and right marginal rows each, one frontoventral cirral row, the presence of caudal cirri, and two dorsal kineties, one of them being a dorsomarginal kinety. Phylogenetic analyses reveal that Heterodeviata is nested in a well-supported clade with Deviata Eigner, 1995, Perisincirra Jankowski, 1978 and Pseudosincirra Gao et al., 2021, which suggests that the family Deviatidae is monophyletic. The close relationship among the Deviatidae genera were supported after extensive morphological and morphogenetic investigations, as well as molecular phylogeny presented here.