Molecular Data Reveal a Cryptic Diversity in the Genus Urotricha (Alveolata, Ciliophora, Prostomatida), a Key Player in Freshwater Lakes, With Remarks on Morphology, Food Preferences, and Distribution

Frontiers in Microbiology

Kuimei Qian¹  Daniela Beisser²  Jens Boenigk²  Sabine Agatha³  Birgit Weißenbacher³  Thorsten Stoeck⁴  Tatyana Darienko⁵  Barbara Kammerlander⁶  Michael Gruber⁷  Gianna Dirren-Pitsch⁸  Sabine Filker⁹  Bettina Sonntag^1,10  Daniela Frantal^1,10  Ulrike Scheffel^1,10  Laura Nachbaur^1,10  Thomas Pröschold^1,10 

[1] 0College of Environmental Engineering, Xuzhou University of Technology, Xuzhou, China;Department of Biodiversity, University of Duisburg-Essen, Essen, Germany;Department of Biosciences, Paris Lodron University of Salzburg, Salzburg, Austria;Ecology Group, Technische Universität Kaiserslautern, Kaiserslautern, Germany;Experimental Phycology and Culture Collection of Algae, University of Göttingen, Göttingen, Germany;Federal Agency for Water Management, Institute for Aquatic Ecology and Fisheries Management, Mondsee, Austria;Hieronymus-Illustrations, Salzburg, Austria;Limnological Station, Department of Plant and Microbial Biology, University of Zurich, Kilchberg, Switzerland;Molecular Ecology Group, Technische Universität Kaiserslautern, Kaiserslautern, Germany;Research Department for Limnology, Mondsee, University of Innsbruck, Mondsee, Austria;

关键词: ciliate plankton;    biogeography;    ciliate diversity;    cryptic species;    microplankton;   

DOI  :  10.3389/fmicb.2021.787290

来源: DOAJ

【 摘 要 】

Species of the ciliate genus Urotricha are key players in freshwater plankton communities. In the pelagial of lakes, about 20 urotrich species occur throughout an annual cycle, some of which play a pivotal role in aquatic food webs. For example, during the phytoplankton spring bloom, they consume a remarkable proportion of the algal production. In ecological studies, urotrich ciliates are usually merely identified to genus rank and grouped into size classes. This is unsatisfying considering the distinct autecological properties of individual species and their specific spatial and temporal distribution patterns. As a basis for future research, we characterized in detail four common urotrich morphotypes, i.e., specimens identified as U. furcata and tentatively as U. agilis, U. pseudofurcata, and U. castalia, using state-of-the-art methods. We used an integrative polyphasic approach, in which morphological studies (in vivo observation, silver staining methods, scanning electron microscopy) were linked with a molecular approach exploiting four different gene fragments as taxonomic DNA barcodes with different resolution potential (SSU rDNA, ITS-1, ITS-2, hypervariable V4 and V9 regions of the SSU rDNA). We shed light on the diversity of urotrich ciliates as well as on their global distribution patterns, and annual cycles. Additionally, we coupled individual species occurrences and environmental parameters, and subsequently modeled the distribution and occurrence, using logistic regressions. Furthermore, for one strain putatively identified as U. castalia, we ascertained the optimal cultivation media and food preferences. Thereby, our comprehensive view on these important freshwater ciliates that frequently occur in environmental high throughput sequencing datasets worldwide will allow future studies to better exploit protistan plankton data from lakes.

【 授权许可】

Unknown