Biodiversity of freshwater ciliates(Protista,Ciliophora)in the Lake Weishan Wetland,China:the state of the

Ciliates are core components of the structure of and function of aquatic microbial food webs.They play an essential role in the energy flow and material circulation within aquatic ecosystems.However,studies on the taxonomy and biodiversity of freshwater ciliates,especially those in wetlands in China are limited.To address this issue,a project to investigate the freshwater ciliates of the Lake Weishan Wetland,Shandong Province,commenced in 2019.Here,we summarize our findings to date on the diversity of ciliates.A total of 187 ciliate species have been found,94 of which are identified to species-level,87 to genus-level,and six to family-level.These species show a high morphological diversity and represent five classes,i.e.,Heterotrichea,Litostomatea,Prostomatea,Oligohymenophorea,and Spirotrichea.The largest number of species documented are oligohymenophoreans.A comprehensive database of these ciliates,including morphological data,gene sequences,microscope slide specimens and a DNA bank,has been established.In the present study,we provide an annotated checklist of retrieved ciliates as well as information on the sequences of published species.Most of these species are recorded in China for the first time and more than 20%are tentatively identified as new to science.Additionally,an investigation of environmental DNA revealed that the ciliate species diversity in Lake Weishan Wetland is higher than previously supposed.

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.