Diversity of the karyorelictid ciliates: Remanella (Protozoa, Ciliophora, Karyorelictida) inhabiting intertidal areas of Qingdao, China, with descriptions of three species

During recent faunistic studies of psammophilic ciliates of the Yellow Sea coast of northern China, three Remanella species were isolated and investigated using living observation and silver staining methods. Their small subunit (SSU) rRNA genes were sequenced in order to analyse their molecular phylogeny. Remanella sinica sp. nov. can be recognized by its large size (200-320 μm long in vivo), dark colour due to the presence of brown cortical granules, single Müller vesicle and 18-20 right lateral ciliary rows. Remanella minuta (Dragesco, 1954) Foissner, 1996 and R. granulosa (Kahl, 1933) Foissner, 1996, are redescribed based on the Chinese populations and improved diagnoses of both are supplied. The SSU rRNA gene sequence data support the validity of these three species. Phylogenetic analyses indicated that all karyorelicteans for which sequence data are available belong to a monophyletic assemblage that is divided into four groups corresponding to the four families: Loxodidae, Geleiidae, Kentrophoridae and Trachelocercidae. Remanella minuta and R. granulosa cluster with the clade of Loxodes forming a group that is sister to the clade containing R. sinica sp. nov. and Remanella sp. However, the monophyly of the genus Remanella was not rejected by the Shimodaira-Hasegawa test (P = 0.553 > 0.05). Remanella trichocysta is considered a junior synonym of R. granulosa.