On four epibiotic peritrichous ciliates(Protozoa,Ciliophora)found in Lake Weishan Wetland:morphological and molecular data support the establishment of a new genus,Parapiosoma gen.nov.,and two new species

During a study on the diversity of ciliated protists in Lake Weishan Wetland,the largest wetland in northern China,four epibiotic sessilid peritrichs were isolated from aquatic host animals.Two of them,i.e.,Epistylis cambari Kellicott,1885 and Epistylis lwof Fauré-Fremiet,1943,were known species whereas the other two,i.e.,Parapiosoma typicum gen.nov.,sp.nov.and Orborhabdostyla gracilis sp.nov.,are new to science.The new genus Parapiosoma gen.nov.is characterized by its branched non-contractile stalk,everted peristomial lip,obconical macronucleus and transverse silverlines.Two species are assigned to the new genus,namely Parapiosoma typicum sp.nov.and Parapiosoma gasterostei(Fauré-Fremiet,1905)comb.nov.Morphologically,P.typicum sp.nov.is recognized by its goblet-shaped zooids,single-layered peristomial lip,dichotomously branched stalk,and infundibular polykinety 3(P3)containing three equal-length rows.Orborhabdostyla gracilis sp.nov.is characterized by its slender zooid,curved macronucleus,and three equal-length rows in infundibular P3.Improved diagnoses and redescriptions of E.cambari and E.lwof are provided including,for the frst time,data on the ciliature of E.cambari.Phylogenetic analyses based on SSU rDNA,ITS1-5.8S rDNA-ITS2,and LSU rDNA sequence data strongly support the assertion that the family Epistylididae comprises morphospecies with diferent evolutionary lineages and indicate that Parapiosoma gen.nov.may represent a new taxon at family level.

Integrative studies on three new freshwater Amphileptus species(Ciliophora,Pleurostomatida)discovered in northern China

The morphology and molecular phylogeny of freshwater pleurostomatid ciliates are insufficiently explored.In the present study,we investigated three new Amphileptus species discovered in Lake Weishan and its vicinity,northern China,using standard alpha-taxonomic methods.Amphileptus paracarchesi sp.nov.is characterized by a lateral fossa(groove)in the posterior body portion,four macronuclear nodules,contractile vacuoles distributed along the dorsal margin,and 4-6 left and 44-50 right somatic kineties.Amphileptus pilosus sp.nov.differs from congeners by having 4-14 macronuclear nodules,numerous contractile vacuoles scattered throughout the cytoplasm,and 22-31 left and 35-42 right somatic kineties.Amphileptus orientalis sp.nov.is characterized by two ellipsoidal macronuclear nodules,three ventral contractile vacuoles,and about four left and 31-35 right somatic kineties.Phylogenetic analyses of nuclear small subunit ribosomal DNA(SSU rDNA)sequences indicate that the family Amphileptidae might be monophyletic while the genus Amphileptus is paraphyletic,as Pseudoamphileptus macrostoma robustly groups with Amphileptus sp.Although deep phylogenetic relationships of amphileptids are poorly resolved,multiple well-delimited species groups are recognizable within the genus Amphileptus.

A new contribution to the taxonomy and phylogeny of the ciliate genus Spirostomum(Alveolata,Ciliophora,Heterotrichea),with comprehensive descriptions of two species from wetlands in China

Species of the ciliate genus Spirostomum Ehrenberg,1834 are distributed worldwide and have a research history spanning more than two centuries.However,species delimitation and phylogenetic relationships within this genus are still uncertain due to the paucity of stable morphologic characters for species separation and the unavailability of accompanying morphological data for most molecular sequences in public databases.In the present study,S.yagiui Shigenaka,1959(three populations)and S.caudatum(Müller,1786)Delphy,1939(one population)were investigated using morphological and molecular methods for the first time in China.Detailed morphological data for the two species were documented,and improved diagnoses were supplied based on a combination of previous studies and the current work.It should be highlighted that there were three different atypical morphotypes identified in a Ningbo population of S.yagiui which may represent various stages in conjugative reproduction.Molecular phylogenies based on 18S,ITS1-5.8S-ITS2,and 28S rRNA gene sequences show that the genus Spirostomum is monophyletic,however,the internal relationships inferred from different genes were poorly resolved but suggest that the species with a moniliform macronucleus comprise an early-diverging clade within this genus.Finally,the global distribution of Spirostomum is summarized based on previous and present studies.