Abstract
A novel hypotrichous ciliate, Oxytrichachongqingica sp. nov., was identified in Chongqing, southwestern China. This species is distinguishable from congeners by various qualitative and quantitative characteristics, such as body size and shape, pattern of endoral and paroral, number of macronuclear nodules, presence and arrangement of cortical granules, as well as ventral and dorsal ciliature. Phylogenetic analyses based on small subunit ribosomal DNA (SSU rDNA) sequences indicate that Oxytrichachongqingica sp. nov. forms a cluster with O.nauplia, Allotrichidesantarcticus, O.paragranulifera, O.quadricirrata, Paroxytrichalongigranulosa, and P.ottowi, albeit with weak or moderate nodal support (82 ML and 0.87 BI).