A new contribution to the taxonomy and molecular phylogeny of three, well-known freshwater species of the ciliate genus Spirostomum (Protozoa: Ciliophora: Heterotrichea)

Members of the heterotrich genus Spirostomum are commonly found in freshwater or low salinity biotopes. In the present study, three species (S. minus, S. subtilis and S. teres) collected from freshwater habitats in Qingdao, China, are investigated using morphological and molecular methods. Detailed morphometric data are documented and improved diagnosis are supplied based on a combination of previous and present studies. In addition, small...