Taxonomy Studies Of 18 Freshwater Ciliates In Qixing River Wetland

As a large group of the highest and most complex differentiated unicellular eukaryotes,the ciliate protozoa are diverse and widely distributed in multiple habitats,with high species diversity.In addition,ciliates are good environmental indicator organisms because of their short life history,high reproduction rate,and high sensitivity to the environment.The Qixing River Wetland,located in the north of Baoqing County,Heilongjiang Province,in the hinterland of the Sanjiang Plain,which is a microcosm of the original swampy wetland ecosystem of the Sanjiang Plain in northeast China.It has an abundant biodiversity,a wide variety of plants,wild animals and birds,and is one of the most critical areas for the conservation of wetlands and their biological resources worldwide.However,compared to the mid-and low-latitude regions,studies on ciliate taxonomy in this particular habitat of freshwater marsh wetlands are largely unexplored in high-latitude alpine regions worldwide,and thus basic information is severely lacking.In the present study,a one-year taxonomic survey of 18 species of ciliates in the Qixing River Wetland was conducted from 2021 to the present,using the Qixing River Marsh Wetland within the Sanjiang Plain basin as the main study site.The study includes: Based on taxonomic identification information of modern standards,providing detailed morphological information,cilia schema accurate to species level,and gene sequence information of new taxa.Further enrich the taxonomic data of freshwater ciliates.The details are as follows:1.The morphology,detailed description,and species identification characteristics of 18 species were identified by modern taxonomic research techniques of ciliates such as in vivo observation and silver staining.The information can provide a reference for the taxonomy of ciliates in the Sanjiang Plain area.2.Several new orders were established,and new populations and known populations were described in detail.One new genus,Variuronema Hao et al.,2022,and seven new species,Variuronema elegans Hao et al.,2022,Variuronema similis Hao et al.,2022,Uronema rigidum Hao et al.,2022,Blepharisma orientale Hao et al.,2022,Blepharisma sinicum Hao et al.,2022,Anteglaucoma vorax n.sp.and Paramecium heilongjiangensis n.sp.And provide detailed redescriptions of known species with complementary definitions based on new characters of new populations.3.The 18 s SSU r RNA sequences of five new species(Variuronema elegans Hao et al.,2022,Variuronema similis Hao et al.,2022,Uronema rigidum Hao et al.,2022,Blepharisma orientale Hao et al.,2022,Blepharisma sinicum Hao et al.,2022)and similar species of two known species(Cinetochilum cf.ovale and Lembadion cf.lucens)were sequenced and submitted to the international genetic database.The sequences were submitted to the international gene database Gen Bank.The corresponding sequence information was analyzed,and evolutionary trees were established to assist morphological characterization,and clarify the evolutionary status of the positional study populations as well as the affinities of closely related species for analysis and discussion.Therefore,in the present study,modern research techniques and methods were used to investigate the taxonomy of 18 freshwater species(belonging to 12 families,11 orders,6 classes)in the ciliates of the Qixing River Wetland,establish new orders,supplement the small subunit r RNA(SSU r RNA)gene sequence of new populations,and explore the system status and affinities of important populations.While providing references for related studies at home and abroad.