The Morphology And Phylogenetic Analysis Of Two New Species (Ciliophera,Peritrichida)

A freshwater peritrich, Epistylis hangzhouensis n. sp., was collected from West Lake, Hangzhou, China, and its morphology, infraciliature, silverline system and SSU rRNA gene sequence were investigated based on living and silver-impregnated specimens. Epistylis hangzhouensis n. sp. has long, symmetrically dichotomously branched stalks; its zooid is elongate vase-shaped and longer than the individual stalk branches, measureing ca.160-260x50-95μm in vivo and containing a thick, undivided peristomial lip. It has a single ventrally located contractile vacuole, and a transversely located, horseshoe-shaped macronucleus., Its haplokinety and polykinety complete one and three-fouth circuits on the peristome before entering the infundibulum. It has127-176transverse silverlines from the oral area and the trochal band (TB) and49-84from the TB to the scopula,. The SSU rRNA gene sequence data places Epistylis hangzhouensisn. sp. as a distinct lineage near Epistylis wenrichiand Epistylis urceola.The morphology and the small subunit (SSU) rRNA gene sequence of the a new fresh water Epitylis from the artificial river which drainaged from Qiantang river, Hangzhou, China. The study about its morphology, infraciliature and SSU rRNA gene sequence were based on living and silver-impregnated specimens. Slender and transparent body measuring80-130×25-35μm in vivo and present a thin, undivided peristomial lip. It has a single apical located contractile vacuole, and a macronucleus, short-C or elongate kidney-shaped, transversely located. Haplokinety and polykinety paralleled to each other and circled the peristomial disc about1.25turns, the first and the second infundibular polykinetids are composed by three rows of kinetosomes, the specific third one is only one row and boldfaced. Pellicular striae uniformly, measuring160-260,50-95on either side of trochal band. The SSU rRNA gene sequence places Epistylis xiashaensis n. sp. as a distinct lineage, as a distinct lineage near Epistylisplicatitis from Wuhan, China.Peritrichious are ciliates that exit development oral cilia, but the somatic ciliature reduced to a trochal band. They constituted a large subclass within the class Oligohymenophorea, Ciliophora, with the majority of species placed in order Sessilida, and the othergroup is the order Mobilida. In recently study, that the Peritrichia is not monophyletic, within the updated of Peritrichia, molecular studies have consistently shown the existence of two major clades. The observed tree topologies given the robustness of their highly support, we suggest that these two clades should be formally recognized as orders, with the names Vorticellida and Operculariida to designate them. In addition, Epistylis appeared in both two orders, tending to occupy basal positions. This suggests that characteristics used to define this species may be plesiomorphic for Peritrichia, as a result the Epistylis may represent as an assemblage of basal species which retaining ancestral features.