The morphology and infraciliature of a new marine colepid ciliate, A＇pocoleps magnus gen. nov., spec. nov., are de- scribed based on living observations and silver impregnations. The new genus Apocoleps is characteri...The morphology and infraciliature of a new marine colepid ciliate, A＇pocoleps magnus gen. nov., spec. nov., are de- scribed based on living observations and silver impregnations. The new genus Apocoleps is characterized by having 8 （vs. 6 in most other related genera） armour tiers, spines at both ends of the cell, 3 adoral organelles and plates with 4 reniform uni-windows. Apo- coleps magnus spec. nov. is defined by the following features： body elongated and slightly curved, about 100-120p.mx 3545 lam in vivo; anterior tertiary tier plate with four uni-windows, most secondary and main tier plates with four uni-windows, posterior tertiary tier plate with two uni-windows; left plate margin slightly serrated; on average 23 transverse and 22 longitudinal ciliary rows; one terminal contractile vacuole; marine habitat.展开更多
Although the taxonomy of oligotrich ciliates has been widely investigated,yet the species diversity remains poorly known.We newly designed a pair of oligotrich-specific LSU rDNA primers covering the 600-bp D1/D2 regio...Although the taxonomy of oligotrich ciliates has been widely investigated,yet the species diversity remains poorly known.We newly designed a pair of oligotrich-specific LSU rDNA primers covering the 600-bp D1/D2 region,and it was effective for detecting oligotrich species.Using the primers,we constructed the cloning libraries to investigate the species diversity of oligotrichs in the northern coastal waters of the South China Sea.In total,165 oligotrich sequences were obtained from five widely separated sampling sites.Sixty operational taxonomic units(OTUs)were obtained at 99%similarity threshold,and low-abundance OTUs with no more than two sequences contributed most of these(about 78%).Our findings are consistent with previous morphological studies,Strombidium was found the most abundant and widely distributed genus in this area.In addition,the BLAST search in the NCBI database resulted in 95%OTUs matching with named oligotrich species in similarity below 99%.Therefore,oligotrich morphospecies diversity has been underestimated as low-abundance species,and the LSU rDNA oligotrich sequence database needs to be better promoted.展开更多
Pleurostomatid ciliates,as a highly diverse and widely distributed unicellular eukaryote group,play a crucial role in the cycling of nutrients and energy in microbial food webs.However,research on pleurostomatids rema...Pleurostomatid ciliates,as a highly diverse and widely distributed unicellular eukaryote group,play a crucial role in the cycling of nutrients and energy in microbial food webs.However,research on pleurostomatids remains insufficient,resulting in a paucity of molecular information and substantial gaps in knowledge of their phylogenetic relationships.In recent years,we investigated pleurostomatid diversity in various Chinese habitats,including their systematic relationships and taxonomic circumscriptions,which were comprehensively analyzed using an integrative morphomolecular approach.Results revealed that:(1)pleurostomatids can be categorized into two suborders,Protolitonotina subord.nov.and Amphileptina Jankowski,1967;(2)Protolitonotina subord.nov.represents the ancestral pleurostomatid group and includes two genera,Protolitonotus and Heterolitonotus gen.nov.,characterized by right kineties progressively shortened along rightmost full kineties and absence of a left dorsolateral kinety;(3)Heterolitonotus gen.nov.represents an orphan lineage and is defined by an oral slit extending to its dorsal margin;(4)“Protolitonotus clampi”does not group with congeners but instead represents an orphan lineage,thus Novilitonotus gen.nov.is established to which P.clampi is transferred as Novilitonotus clampi comb.nov.;(5)three new species,Apoamphileptus paraclaparedii sp.nov.,Heterolitonotus rex gen.nov.,sp.nov.,and Loxophyllum apohelus sp.nov.,are described;and(6)helices 21es6a to 21es6d within the V4 region of small subunit ribosomal RNA(SSU rRNA)may serve as a useful tool for discriminating pleurostomatids.The evolutionary relationships among all main lineages of pleurostomatids are discussed and a key to the identification of pleurostomatid genera is provided.展开更多
Ciliated protists(ciliates)represent a morphologically and genetically diverse group of single-celled eukaryotes,the phylogeny of which is critical for understanding eukaryotic evolution.Through international collabor...Ciliated protists(ciliates)represent a morphologically and genetically diverse group of single-celled eukaryotes,the phylogeny of which is critical for understanding eukaryotic evolution.Through international collaborations,the Laboratory of Protozoology at Ocean University of China(OUC-group)has conducted detailed research on ciliate phylogeny based on expanded taxonomic sampling,employing single gene as well as multi-gene markers,and phylogenomic datasets.We have systematically investigated>1000 ciliate species spanning~40 orders,sampled from diverse biotopes including marine environments in China seas and freshwater wetlands.This comprehensive sampling has generated three key datasets:(1)genomic DNA extracts from~2600 strains,(2)~2300 sequences of marker genes,and(3)single-cell genomic and/or transcriptomic datasets from~120 species.Based on these datasets,the phylogenetic relationships covering all classes and most orders have been thoroughly reconstructed and investigated,resulting in the establishment of 93 new supraspecies taxa comprising two classes(Mesodiniea and Protocruziea),two subclasses(Protohypotrichia and Synhymenia),two orders(Wilbertomorphida and Lynnellida),11 families,and 76 genera.Moreover,we have reconstructed a genome-scale tree of life for ciliates and provided an updated classification of the phylum Ciliophora.Furthermore,based on the robust phylogenetic tree of ciliates,we provide more reliable estimates for the origins and divergence times of the main ciliate groups.Future studies integrating advanced genomics,innovations in culturing and interdisciplinary applications will refine the ciliate tree of life,with broader impacts for our understanding of eukaryotic evolution and biodiversity.展开更多
Methanogenic endosymbionts are the only known intracellular archaeans and are especially common in anaerobic ciliated protists.Studies on the evolution of associations between anaerobic ciliates and their methanogenic...Methanogenic endosymbionts are the only known intracellular archaeans and are especially common in anaerobic ciliated protists.Studies on the evolution of associations between anaerobic ciliates and their methanogenic endosymbionts offer an excellent opportunity to broaden our knowledge about symbiosis theory and adaptation of eukaryotes to anoxic environments.Here,the diversity of methanogenic endosymbionts was analyzed with the addition of nine anaerobic ciliate populations that were newly studied by various methods.Results showed that diverse anaerobic ciliates host methanogenic endosymbionts that are limited to a few genera in orders Methanomicrobiales,Methanobacteriales,and Methanosarcinales.For the first time,anaerobic ciliates of the classes Muranotrichea and Prostomatea were found to host methanogenic endosymbionts.Distinct origins of endosymbiosis were revealed for classes Armophorea and Plagiopylea.We posit that armophoreans and plagiopyleans might have harbored Methanoregula(order Methanomicrobiales)and Methanocorpusculum(order Metha-nomicrobiales),respectively,as methanogenic endosymbionts at the beginning of their evolution.Subsequently,independent endosymbiont replacement events occurred in methanogen-ciliate associations,probably due to ecological transitions,species radiation of ciliate hosts,and vertical transmission bottlenecks of endosymbionts.Our results shed light on the evolution of associations between anaerobic ciliates and methanogens,and identifies the necessary preconditions for illustrating mecha-nisms by which endosymbioses between these partners were established.展开更多
Ciliated protists represent one of the most primitive and diverse lineages of eukaryotes,with nuclear dimorphism,a distinctive sexual process(conjugation),and extensive genome rearrangements.Among divergent ciliate li...Ciliated protists represent one of the most primitive and diverse lineages of eukaryotes,with nuclear dimorphism,a distinctive sexual process(conjugation),and extensive genome rearrangements.Among divergent ciliate lineages,the peritrich order Sessilida includes members with a colonial lifestyle,which may hint to an independent evolutionary attempt for multicellularity,although they are still single-celled organisms.To date,the evolution and phylogeny of this group are still far from clear,in part due to the paucity of molecular and/or morphological data for many taxa.In this study,we extend taxon sampling of a loricate group of sessilids by obtaining 69 new r DNA(SSU r DNA,ITS1-5.8S rDNA-ITS2,and LSU r DNA)sequences from 20 wellcharacterized representative species and analyze the phylogenetic relationships within Sessilida.The main findings are:(i)the genera Rhabdostyla and Campanella each represents a unique taxon at family level,supporting the establishment of two new families,i.e.,Rhabdostylidae n.fam.and Campanellidae n.fam.,respectively,the former being sister to a morphologically heterogeneous clade comprising Astylozoidae and several incertae sedis species and the latter occupying the basal position within the Sessilida clade;(ii)the structure of infundibular polykinety 3 is likely to be a phylogenetically informative character for resolving evolutionary relationships among sessilids;(iii)differences between sparsely and the densely arranged silverline systems could be a suprageneric taxonomic character;(iv)the monophyly of Vaginicolidae is confirmed,which is consistent with its specialized morphology,i.e.,the possession of a typical peritrich lorica which might be an apomorphy for this group;(v)within Vaginicolidae,the monotypic Cothurniopsis sensu Stokes,1893 is a synonym of Cothurnia Ehrenberg,1831,and a new combination is created,i.e.,Cothurnia valvata nov.comb.;(vi)Vaginicola sensu lato comprises at least two distinctly divergent clades,one affiliated with Thuricola and the other with a systematically puzzling clade represented by Vaginicola tincta.展开更多
Heterotrichous ciliates play an important role in aquatic ecosystem energy flow processes and many are model organisms for research in cytology,regenerative biology,and toxicology.In the present study,we combine both ...Heterotrichous ciliates play an important role in aquatic ecosystem energy flow processes and many are model organisms for research in cytology,regenerative biology,and toxicology.In the present study,we combine both morphological and molecular data to infer phylogenetic relationships at family-genus level and propose new evolutionary hypotheses for the class Heterotrichea.The main results include:(1)96 new ribosomal DNA sequences from 36 populations,representing eight families and 13 genera,including three poorly annotated genera,Folliculinopsis,Ampullofolliculina and Linostomella;(2)the earliest-branching families are Spirostomidae in single-gene trees and Peritromidae in the concatenated tree,but the family Peritromidae probably represents the basal lineage based on its possession of many"primitive"morphological characters;(3)some findings in molecular trees are not supported by morphological evidence,such as the family Blepharismidae is one of the most recent branches and the relationship between Fabreidae and Folliculinidae is very close;(4)the systematic positions of Condylostomatidae,Climacostomidae,and Gruberiidae remain uncertain based either on morphological or molecular data;and(5)the monophyly of each genus included in the present study is supported by the molecular phylogenetic trees,except for Blepharisma in the SSU r DNA tree and Folliculina in the ITS1-5.8 S-ITS2 tree.展开更多
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 tax...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.展开更多
Ciliates are one of the oldest living eukaryotic unicellular organisms, widely distributed in the waters around the world. As a typical marine oligotrich ciliate, Strombidium sulcatum plays an important role in marine...Ciliates are one of the oldest living eukaryotic unicellular organisms, widely distributed in the waters around the world. As a typical marine oligotrich ciliate, Strombidium sulcatum plays an important role in marine food webs and energy flow. Here we report the first deep se- quencing and analyses of RNA-Seq data from Strombidium sulcatum. We generated 42,640 unigenes with an N50 of 1,451 bp after de novo assembly and removing rRNA, mitochondrial and bacteria contaminants. We employed SPOCS to detect orthologs from S. sulcatum and 17 other ciliates, and then carried out the phyloge- nomic reconstruction using 127 single copy orthologs. In phylogenomic analyses, concatenated trees have similar topological structures with concordance tree on the class level. Together with phylogenetic networks analysis, it aroused more doubts about the placement of Protocruzia, Mesodinium and Myrionecta. While epi- plasmic proteins are known to be related to morphological characteristics, we found the potential relationship between gene expression of epiplasmic proteins and morphological characteristics. This work supports the use of high throughput approaches for phylogenomic analysis as well as correlation analysis between expression level of target genes and morphological characteristics.展开更多
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 ...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.展开更多
The classification of hypotrichs based on the gonostomatid oral structure is widely accepted,but the phylogenetic signal of this character is unknown.Here,we infer the species phylogeny of those gonostomatids for whic...The classification of hypotrichs based on the gonostomatid oral structure is widely accepted,but the phylogenetic signal of this character is unknown.Here,we infer the species phylogeny of those gonostomatids for which molecular data are available,plus26 new sequences of SSU-rDNA,ITS1-5.8 S-ITS2 and LSU-rDNA genes.The results indicate that:(i)the endoral is more phylogenetically informative than the paroral;(ii)the structure of the endoral and the Gonostomum-pattern adoral zone of membranelles are plesiomorphies for the hypotrichs sensu stricto;(iii)the group of species possessing these features is monophyletic in all our phylogenetic analyses,except that for the SSU-rDNA;(iv)Schmidingerotrichidae is monophyletic in all trees,suggesting that it is a well-defined family;(v)the Gonostomatidae is polyphyletic in the SSU-rDNA and ITS1-5.8 S-ITS2 trees,with Gonostomum,Cladotricha,Cotterillia,Metagonostomum,Paragonostomum and Wallackia distributed among separate clades,but monophyletic in the LSU-rDNA and concatenated trees;(vi)higher hypotrich taxa such as core urostyloids and core sporadotrichids/stichotrichids might have evolved from species that possessed a gonostomatid oral apparatus.展开更多
The subclass Peritrichia,containing two orders Sessilida and Mobilida,is a major group of ciliates with worldwide distribution and high species diversity.Several studies have investigated the phylogeny of peritrichs;h...The subclass Peritrichia,containing two orders Sessilida and Mobilida,is a major group of ciliates with worldwide distribution and high species diversity.Several studies have investigated the phylogeny of peritrichs;however,the evolutionary relationships and classification of some families and genera within the Sessilida remain unclear.In the present study,we isolated and identified 22 peritrich populations representing four families and six genera and obtained 64 rDNA sequences to perform phylogenetic analyses and assess their systematic relationships.Ancestral character reconstruction was also carried out to infer evolutionary routes within the Sessilida.The results indicate:(1)family Vaginicolidae is monophyletic and acquisition of the typical peritrich lorica represents a single evolutionary divergence;(2)core epistylidids evolved from a Zoothamnium-like ancestor and experienced spasmoneme loss during evolution;(3)Campanella clusters with species in the basal clade and shows stable morphological differences with other epistylidids,supporting its assignment to a separate family;(4)the structure of the peristomial lip may be a genus-level character rather than a diagnostic character for discriminating Epistylididae and Operculariidae,thus a redefinition of Operculariidae should be carried out when more species have been investigated;(5)some characters,such as lifestyle(solitary or colonial),spasmoneme and living habit(sessile or free-swimming),evolved repeatedly among sessilids indicating that species with non-contractile stalks or that are free-swimming have multiple evolutionary routes and might derive from any sessilid lineage without a lorica.The close phylogenetic relationships of some morphologically distinct sessilids imply that the diagnoses of some genera and families should be improved.展开更多
Recent studies have revealed a high diversity of pleurostomatid ciliates in brackish habitats. Here, a novel species, Pseudolitonotus spirelis gen. et sp. n., isolated from a mangrove wetland of southern China, was in...Recent studies have revealed a high diversity of pleurostomatid ciliates in brackish habitats. Here, a novel species, Pseudolitonotus spirelis gen. et sp. n., isolated from a mangrove wetland of southern China, was investigated based on living observation, protargol staining, and molecular analyses. The new genus Pseudolitonotus gen. n. is characterized by the last left somatic kinety (LKn) being shortened and none of the right somatic kineties extending to the anterior end of the cell, thus distinguishing it from all known pleurostomatid genera. The type species, Pseudolitonotus spirelis sp. n., is characterized by the possession of two macronuclear nodules, 11–15 right and 7–9 left kineties, a single contractile vacuole subterminally located, extrusomes evenly spaced along the entire ventral margin and some forming an “apical group”, two types of cortical granules, and the bottom of the oral slit invariably being twisted. Litonotus gracilis (Pan et al. Eur J Protistol 51:494–506, 2015) is believed to be another member of this new genus as its LKn and right somatic kineties are all shortened. Hence, a new combination, Pseudolitonotus gracilis (Pan et al., 2015) comb. n., is suggested and its diagnosis is improved. Molecular phylogenetic analyses based on SSU rDNA sequence data reveal that Pseudolitonotus gen. n. is monophyletic and groups with Apolitonotus (Pan et al. J Eukaryot Microbiol 67:252–262, 2020) of the family Protolitonotidae (Wu et al. Zool Scr 46:245–253, 2017). However, the familial assignment of this new genus is uncertain based on current data.展开更多
The morphology and infraciliature of the new hypotrichous ciliate,Oxytricha xianica sp.nov.,and a Chinese population of Oxytricha auripunctata Blatterer&Foissner,1988,are investigated using live observation and pr...The morphology and infraciliature of the new hypotrichous ciliate,Oxytricha xianica sp.nov.,and a Chinese population of Oxytricha auripunctata Blatterer&Foissner,1988,are investigated using live observation and protargol staining.Oxytricha xianica sp.nov.is defined by the body size 85-130µm×30-50µm in vivo,the typical oxytrichid 18 frontoventral-transverse cirri,cortical granules absent,undulating membranes reduced or absent,three caudal cirri,dorsal kineties in Oxytricha pattern,and two ellipsoidal macronuclear nodules.The Chinese population of O.auripunctata differs slightly from other populations in the arrangement and color of cortical granules and position of anterior end of dorsal kinety 4.Phylogenetic analyses based on SSU-rDNA sequences support the assertion that O.auripunctata belongs to Oxytricha and Oxytrichidae.展开更多
Zoothamnium is a speciose genus,most species of which have incomplete morphological data based on modern criteria.In the present study,the morphology of three species of Zoothamnium,i.e.,Z.apoarbuscula n.sp.,Z.apohent...Zoothamnium is a speciose genus,most species of which have incomplete morphological data based on modern criteria.In the present study,the morphology of three species of Zoothamnium,i.e.,Z.apoarbuscula n.sp.,Z.apohentscheli n.sp.,and Z.alternans,collected in Qingdao,China,was revealed using living observation and silver staining.In addition,the SSU rDNA of each species was sequeneed for phylogenetic analyses.Zoothamnium apoarbuscula n.sp.is characterized by its umbellate colony which is up to 900 pm high,dichotomously branched stalk,differentiation of zooids,and infundibular polykinety 3 comprising three equal-length ciliary rows.Zoothamnium apohentscheli n.sp is characterized by its large colony up to 1700 pm high,alternately branched stalk,and infundibular polykinety 3 comprising three equal-length ciliary rows.A population of Z.altenums is described in detail.Phylogenetic analyses based on SSU rDNA sequence data revealed that species with an alternately branched stalk cluster together in gene trees and probably represent an independent lineage within the genus Zoothamnium.展开更多
Anaerobic protists in general,and ciliates in particular,are important components of anoxic or hypoxic environments,however,their diversity remains underestimated.Sonderia is a poorly studied genus that is distributed...Anaerobic protists in general,and ciliates in particular,are important components of anoxic or hypoxic environments,however,their diversity remains underestimated.Sonderia is a poorly studied genus that is distributed worldwide and is commonly found in anaerobic environments.In the present study,the taxonomy and phylogeny of three new species,namely Sonderia aposinuata sp.nov.,Sonderia paramacrochilus sp.nov.and Sonderia steini sp.nov.,collected from China,were investigated based on microscopic observations and SSU rRNA gene sequencing methods.Sonderia aposinuata sp.nov.is diagnosed mainly by having a relatively large body size,a crescent-shaped oral opening,numerous slender extrusomes,one suture on the ventral side and two on the dorsal side,and a buccal cavity that occupies the anterior third of the cell.Sonderia paramacrochilus sp.nov.closely resembles S.macrochilus but differs mainly by its oral opening being located closer to the anterior cell margin and its spindle-shaped extrusomes.Sonderia steini sp.nov.is a freshwater species that can be recognized by its shallow buccal cavity,sparsely distributed rod-shaped extrusomes,and having 68–79 monokinetidal somatic kineties that form sutures on both sides of the body.Phylogenetic analyses based on small subunit ribosomal RNA(SSU rRNA)gene sequence data support the monophyly of the family Sonderiidae,however,Sonderia is paraphyletic.The genus Sonderia is briefly revised and a key to the identification of species belonging to this genus is supplied.展开更多
Aquaculture of red swamp crayfish Procambarus clarkii is an emerging farming industry in China.As shown recently,one of the most significant diseases affecting the red swamp crayfish is caused by overabundance of epib...Aquaculture of red swamp crayfish Procambarus clarkii is an emerging farming industry in China.As shown recently,one of the most significant diseases affecting the red swamp crayfish is caused by overabundance of epibiotic peritrichs,a group of ciliated protists that are commonly found living as epibionts on aquatic animals.Nevertheless,few studies focusing on this issue have been performed.As part of a faunal study carried out in the Lake Weishan Wetland,China,four colonial sessilid peritrichs,namely Epicarchesium granulatum,Epistylis bimarginata,Epistylis semiciculus,and Zoothamnium procerius,attached to P.clarkii are documented.For each species,redescriptions and improved diagnoses are supplied.As a further aid to identification,14 new rDNA sequences of these four and a closely related species were obtained.In addition,as an aid for future studies on epibiotic ciliates,we supply a list and information about recent integrative studies that document the geographic distributions of related taxa.展开更多
Colonization features of biofilm-dwelling protozoa,especially ciliates,are routinely used as a useful tool for marine bioassessment.In this review,we summarize some of these features to develop an optimal sampling str...Colonization features of biofilm-dwelling protozoa,especially ciliates,are routinely used as a useful tool for marine bioassessment.In this review,we summarize some of these features to develop an optimal sampling strategy for using biofilmdwelling protozoa as bioindicators of marine water quality.We focus on the utility of:(1)diversity in dices to analyze the colonizahon features of biofilm-dwelling protozoa for monitoring marine water quality;(2)MacArthur-Wilson and logistic equation models to determine spatio-temporal variations in colonization dynamics;and(3)homogeneity in taxonomic breadth of biofilm-dwelling protozoa during the process of colonization.The main findings are that:(1)the colonization dynamics of biofilm-dwelling protozoa are similar at depths of 1-5 m in spring and autumn;(2)temporal variability was well fitted to the MacArthur-Wilson and logistic models(P<0.05);and(3)species composition reached an equilibrium after a colonization period of 10-14 days in spring and autumn,but this took less time in the summer and more time in the winter.Ellipse-plotting tests demonstrated spatial variability in homogeneity in taxonomic structure of the ciiiate communities at different depths in the water column,with high levels at 1 m and 2 m and lower levels at 3.5 m and 5 m.Thus,the findings of this review suggest that the colonization dynamics of biofilin-dwelling protozoa may be influenced by different depths and seasons in coastal waters and 1-2 m in spring and autumn may be optimal sampling strategy for bioassessment on large spatial/temporal scales in marine ecosystems.展开更多
基金supported by ‘the Natural Science Foundation of China’ (Project No. 30870264)the Darwin Initiative Programme (Project No. 14-015)
文摘The morphology and infraciliature of a new marine colepid ciliate, A＇pocoleps magnus gen. nov., spec. nov., are de- scribed based on living observations and silver impregnations. The new genus Apocoleps is characterized by having 8 （vs. 6 in most other related genera） armour tiers, spines at both ends of the cell, 3 adoral organelles and plates with 4 reniform uni-windows. Apo- coleps magnus spec. nov. is defined by the following features： body elongated and slightly curved, about 100-120p.mx 3545 lam in vivo; anterior tertiary tier plate with four uni-windows, most secondary and main tier plates with four uni-windows, posterior tertiary tier plate with two uni-windows; left plate margin slightly serrated; on average 23 transverse and 22 longitudinal ciliary rows; one terminal contractile vacuole; marine habitat.
基金Supported by the National Natural Science Foundation of China(Nos.31772440,31430077,41576124,31761133001)the Pearl River Science and Technology Nova Program of Guangzhou(No.201610010162) to YZ+1 种基金Guangdong MEPP Fund(No.GDOE(2019)A23)the Special Support Program of Guangdong Province to YZ
文摘Although the taxonomy of oligotrich ciliates has been widely investigated,yet the species diversity remains poorly known.We newly designed a pair of oligotrich-specific LSU rDNA primers covering the 600-bp D1/D2 region,and it was effective for detecting oligotrich species.Using the primers,we constructed the cloning libraries to investigate the species diversity of oligotrichs in the northern coastal waters of the South China Sea.In total,165 oligotrich sequences were obtained from five widely separated sampling sites.Sixty operational taxonomic units(OTUs)were obtained at 99%similarity threshold,and low-abundance OTUs with no more than two sequences contributed most of these(about 78%).Our findings are consistent with previous morphological studies,Strombidium was found the most abundant and widely distributed genus in this area.In addition,the BLAST search in the NCBI database resulted in 95%OTUs matching with named oligotrich species in similarity below 99%.Therefore,oligotrich morphospecies diversity has been underestimated as low-abundance species,and the LSU rDNA oligotrich sequence database needs to be better promoted.
基金supported by the National Natural Science Foundation of China(32030015,32170533)Researchers Supporting Project Number(RSP2024R10)King Saud University,Riyadh,Saudi Arabia。
文摘Pleurostomatid ciliates,as a highly diverse and widely distributed unicellular eukaryote group,play a crucial role in the cycling of nutrients and energy in microbial food webs.However,research on pleurostomatids remains insufficient,resulting in a paucity of molecular information and substantial gaps in knowledge of their phylogenetic relationships.In recent years,we investigated pleurostomatid diversity in various Chinese habitats,including their systematic relationships and taxonomic circumscriptions,which were comprehensively analyzed using an integrative morphomolecular approach.Results revealed that:(1)pleurostomatids can be categorized into two suborders,Protolitonotina subord.nov.and Amphileptina Jankowski,1967;(2)Protolitonotina subord.nov.represents the ancestral pleurostomatid group and includes two genera,Protolitonotus and Heterolitonotus gen.nov.,characterized by right kineties progressively shortened along rightmost full kineties and absence of a left dorsolateral kinety;(3)Heterolitonotus gen.nov.represents an orphan lineage and is defined by an oral slit extending to its dorsal margin;(4)“Protolitonotus clampi”does not group with congeners but instead represents an orphan lineage,thus Novilitonotus gen.nov.is established to which P.clampi is transferred as Novilitonotus clampi comb.nov.;(5)three new species,Apoamphileptus paraclaparedii sp.nov.,Heterolitonotus rex gen.nov.,sp.nov.,and Loxophyllum apohelus sp.nov.,are described;and(6)helices 21es6a to 21es6d within the V4 region of small subunit ribosomal RNA(SSU rRNA)may serve as a useful tool for discriminating pleurostomatids.The evolutionary relationships among all main lineages of pleurostomatids are discussed and a key to the identification of pleurostomatid genera is provided.
基金supported by the Science&Technology Innovation Project of Laoshan Laboratory(No.LSKJ202203201)the Natural Science Foundation of China(32030015,32270539,32470512,32300368,32370475,32300345)+3 种基金the Young Taishan Scholar Program of Shandong Province(tsqn202408084)Inner Mongolia Natural Science Foundation(2023QN03016)Special Research Project for First-class Disciplines of the Department of Education of the Inner Mongolia Autonomous Region of China(YLXKZX-ND-039)the Ongoing Research Funding Program(ORF-2025-7),King Saud University,Riyadh,Saudi Arabia.
文摘Ciliated protists(ciliates)represent a morphologically and genetically diverse group of single-celled eukaryotes,the phylogeny of which is critical for understanding eukaryotic evolution.Through international collaborations,the Laboratory of Protozoology at Ocean University of China(OUC-group)has conducted detailed research on ciliate phylogeny based on expanded taxonomic sampling,employing single gene as well as multi-gene markers,and phylogenomic datasets.We have systematically investigated>1000 ciliate species spanning~40 orders,sampled from diverse biotopes including marine environments in China seas and freshwater wetlands.This comprehensive sampling has generated three key datasets:(1)genomic DNA extracts from~2600 strains,(2)~2300 sequences of marker genes,and(3)single-cell genomic and/or transcriptomic datasets from~120 species.Based on these datasets,the phylogenetic relationships covering all classes and most orders have been thoroughly reconstructed and investigated,resulting in the establishment of 93 new supraspecies taxa comprising two classes(Mesodiniea and Protocruziea),two subclasses(Protohypotrichia and Synhymenia),two orders(Wilbertomorphida and Lynnellida),11 families,and 76 genera.Moreover,we have reconstructed a genome-scale tree of life for ciliates and provided an updated classification of the phylum Ciliophora.Furthermore,based on the robust phylogenetic tree of ciliates,we provide more reliable estimates for the origins and divergence times of the main ciliate groups.Future studies integrating advanced genomics,innovations in culturing and interdisciplinary applications will refine the ciliate tree of life,with broader impacts for our understanding of eukaryotic evolution and biodiversity.
基金supported by the National Natural Science Foundation of China(32370471,32070406)Basic and Applied Basic Research Founda-tion of Guangdong Province(2024A1515011110)the Project(No.RSP2025R7)of King Saud University,Saudi Arabia.
文摘Methanogenic endosymbionts are the only known intracellular archaeans and are especially common in anaerobic ciliated protists.Studies on the evolution of associations between anaerobic ciliates and their methanogenic endosymbionts offer an excellent opportunity to broaden our knowledge about symbiosis theory and adaptation of eukaryotes to anoxic environments.Here,the diversity of methanogenic endosymbionts was analyzed with the addition of nine anaerobic ciliate populations that were newly studied by various methods.Results showed that diverse anaerobic ciliates host methanogenic endosymbionts that are limited to a few genera in orders Methanomicrobiales,Methanobacteriales,and Methanosarcinales.For the first time,anaerobic ciliates of the classes Muranotrichea and Prostomatea were found to host methanogenic endosymbionts.Distinct origins of endosymbiosis were revealed for classes Armophorea and Plagiopylea.We posit that armophoreans and plagiopyleans might have harbored Methanoregula(order Methanomicrobiales)and Methanocorpusculum(order Metha-nomicrobiales),respectively,as methanogenic endosymbionts at the beginning of their evolution.Subsequently,independent endosymbiont replacement events occurred in methanogen-ciliate associations,probably due to ecological transitions,species radiation of ciliate hosts,and vertical transmission bottlenecks of endosymbionts.Our results shed light on the evolution of associations between anaerobic ciliates and methanogens,and identifies the necessary preconditions for illustrating mecha-nisms by which endosymbioses between these partners were established.
基金supported by the Laoshan Laboratory(LSKJ202203201)the National Natural Science Foundation of China(32030015,41976086,32270558,32111530116)+2 种基金Young Taishan Scholar Program of Shandong Province(tsqn202103037)the Fundamental Research Funds for the Central Universities(202141007)the China Postdoctoral Science Foundation(2021M703037)。
文摘Ciliated protists represent one of the most primitive and diverse lineages of eukaryotes,with nuclear dimorphism,a distinctive sexual process(conjugation),and extensive genome rearrangements.Among divergent ciliate lineages,the peritrich order Sessilida includes members with a colonial lifestyle,which may hint to an independent evolutionary attempt for multicellularity,although they are still single-celled organisms.To date,the evolution and phylogeny of this group are still far from clear,in part due to the paucity of molecular and/or morphological data for many taxa.In this study,we extend taxon sampling of a loricate group of sessilids by obtaining 69 new r DNA(SSU r DNA,ITS1-5.8S rDNA-ITS2,and LSU r DNA)sequences from 20 wellcharacterized representative species and analyze the phylogenetic relationships within Sessilida.The main findings are:(i)the genera Rhabdostyla and Campanella each represents a unique taxon at family level,supporting the establishment of two new families,i.e.,Rhabdostylidae n.fam.and Campanellidae n.fam.,respectively,the former being sister to a morphologically heterogeneous clade comprising Astylozoidae and several incertae sedis species and the latter occupying the basal position within the Sessilida clade;(ii)the structure of infundibular polykinety 3 is likely to be a phylogenetically informative character for resolving evolutionary relationships among sessilids;(iii)differences between sparsely and the densely arranged silverline systems could be a suprageneric taxonomic character;(iv)the monophyly of Vaginicolidae is confirmed,which is consistent with its specialized morphology,i.e.,the possession of a typical peritrich lorica which might be an apomorphy for this group;(v)within Vaginicolidae,the monotypic Cothurniopsis sensu Stokes,1893 is a synonym of Cothurnia Ehrenberg,1831,and a new combination is created,i.e.,Cothurnia valvata nov.comb.;(vi)Vaginicola sensu lato comprises at least two distinctly divergent clades,one affiliated with Thuricola and the other with a systematically puzzling clade represented by Vaginicola tincta.
基金supported by the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(2018SDKJ0406-1)the National Natural Science Foundation of China(3203000059,31970398)。
文摘Heterotrichous ciliates play an important role in aquatic ecosystem energy flow processes and many are model organisms for research in cytology,regenerative biology,and toxicology.In the present study,we combine both morphological and molecular data to infer phylogenetic relationships at family-genus level and propose new evolutionary hypotheses for the class Heterotrichea.The main results include:(1)96 new ribosomal DNA sequences from 36 populations,representing eight families and 13 genera,including three poorly annotated genera,Folliculinopsis,Ampullofolliculina and Linostomella;(2)the earliest-branching families are Spirostomidae in single-gene trees and Peritromidae in the concatenated tree,but the family Peritromidae probably represents the basal lineage based on its possession of many"primitive"morphological characters;(3)some findings in molecular trees are not supported by morphological evidence,such as the family Blepharismidae is one of the most recent branches and the relationship between Fabreidae and Folliculinidae is very close;(4)the systematic positions of Condylostomatidae,Climacostomidae,and Gruberiidae remain uncertain based either on morphological or molecular data;and(5)the monophyly of each genus included in the present study is supported by the molecular phylogenetic trees,except for Blepharisma in the SSU r DNA tree and Folliculina in the ITS1-5.8 S-ITS2 tree.
基金supported by the Laoshan Laboratory(No.LSKJ202203201)the National Natural Science Foundation of China(project numbers:32030015,32000300,31961123002)+1 种基金the China Postdoctoral Science Foundation(project number:2021M703037,2022M711922)the Researchers Supporting Project(Project number RSP2022R10)。
文摘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.
基金This work was supported by the Natural Science Foundation of China （Grant Nos. 31430077, 91131013, and 31272285）. Many thanks are given to Prof. Weibo Song （Ocean University of China）, for his indispensable advice during the preparation of the manuscript.
文摘Ciliates are one of the oldest living eukaryotic unicellular organisms, widely distributed in the waters around the world. As a typical marine oligotrich ciliate, Strombidium sulcatum plays an important role in marine food webs and energy flow. Here we report the first deep se- quencing and analyses of RNA-Seq data from Strombidium sulcatum. We generated 42,640 unigenes with an N50 of 1,451 bp after de novo assembly and removing rRNA, mitochondrial and bacteria contaminants. We employed SPOCS to detect orthologs from S. sulcatum and 17 other ciliates, and then carried out the phyloge- nomic reconstruction using 127 single copy orthologs. In phylogenomic analyses, concatenated trees have similar topological structures with concordance tree on the class level. Together with phylogenetic networks analysis, it aroused more doubts about the placement of Protocruzia, Mesodinium and Myrionecta. While epi- plasmic proteins are known to be related to morphological characteristics, we found the potential relationship between gene expression of epiplasmic proteins and morphological characteristics. This work supports the use of high throughput approaches for phylogenomic analysis as well as correlation analysis between expression level of target genes and morphological characteristics.
基金This work was supported by the National Natural Science Foundation of China(Project numbers:32030015,32000300)the Natural Science Foundation of Shandong Province(Project number:ZR2021QC104,ZR2022QC096)+1 种基金China Postdoctoral Science Foundation(Project numbers:2021M701993,2022M711922)the King Saud University,Saudi Arabia(Project number RSP2023R10).We sincerely thank the“Weishan Wetland Station”for institutional support.
文摘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.
基金supported by National Natural Science Foundation of China(31872190)。
文摘The classification of hypotrichs based on the gonostomatid oral structure is widely accepted,but the phylogenetic signal of this character is unknown.Here,we infer the species phylogeny of those gonostomatids for which molecular data are available,plus26 new sequences of SSU-rDNA,ITS1-5.8 S-ITS2 and LSU-rDNA genes.The results indicate that:(i)the endoral is more phylogenetically informative than the paroral;(ii)the structure of the endoral and the Gonostomum-pattern adoral zone of membranelles are plesiomorphies for the hypotrichs sensu stricto;(iii)the group of species possessing these features is monophyletic in all our phylogenetic analyses,except that for the SSU-rDNA;(iv)Schmidingerotrichidae is monophyletic in all trees,suggesting that it is a well-defined family;(v)the Gonostomatidae is polyphyletic in the SSU-rDNA and ITS1-5.8 S-ITS2 trees,with Gonostomum,Cladotricha,Cotterillia,Metagonostomum,Paragonostomum and Wallackia distributed among separate clades,but monophyletic in the LSU-rDNA and concatenated trees;(vi)higher hypotrich taxa such as core urostyloids and core sporadotrichids/stichotrichids might have evolved from species that possessed a gonostomatid oral apparatus.
基金supported by the Laoshan Laboratory(No.LSKJ202203201)the National Key Research and Development Program of China(2020YFD0900303)+3 种基金National Natural Science Foundation of China(project numbers:32030015,32000300,32270481,32100382)Hubei Agricultural Sciences and Technology Innovation Center(2021-620-000-001-33)China Postdoctoral Science Foundation Grant(project numbers:2022M711922,2021M701993)the Researchers Supporting Project(Project number RSP2022R10)of King Saud University,Saudi Arabia.
文摘The subclass Peritrichia,containing two orders Sessilida and Mobilida,is a major group of ciliates with worldwide distribution and high species diversity.Several studies have investigated the phylogeny of peritrichs;however,the evolutionary relationships and classification of some families and genera within the Sessilida remain unclear.In the present study,we isolated and identified 22 peritrich populations representing four families and six genera and obtained 64 rDNA sequences to perform phylogenetic analyses and assess their systematic relationships.Ancestral character reconstruction was also carried out to infer evolutionary routes within the Sessilida.The results indicate:(1)family Vaginicolidae is monophyletic and acquisition of the typical peritrich lorica represents a single evolutionary divergence;(2)core epistylidids evolved from a Zoothamnium-like ancestor and experienced spasmoneme loss during evolution;(3)Campanella clusters with species in the basal clade and shows stable morphological differences with other epistylidids,supporting its assignment to a separate family;(4)the structure of the peristomial lip may be a genus-level character rather than a diagnostic character for discriminating Epistylididae and Operculariidae,thus a redefinition of Operculariidae should be carried out when more species have been investigated;(5)some characters,such as lifestyle(solitary or colonial),spasmoneme and living habit(sessile or free-swimming),evolved repeatedly among sessilids indicating that species with non-contractile stalks or that are free-swimming have multiple evolutionary routes and might derive from any sessilid lineage without a lorica.The close phylogenetic relationships of some morphologically distinct sessilids imply that the diagnoses of some genera and families should be improved.
基金supported by the Natural Science Foundation of China(Project Numbers:42076113,31761133001,41576148)supported by the China Postdoctoral Science Foundation(Project Number:2018M640796)the Guangdong Basic and Applied Basic Research Foundation(Project Number:2020A1515111125).
文摘Recent studies have revealed a high diversity of pleurostomatid ciliates in brackish habitats. Here, a novel species, Pseudolitonotus spirelis gen. et sp. n., isolated from a mangrove wetland of southern China, was investigated based on living observation, protargol staining, and molecular analyses. The new genus Pseudolitonotus gen. n. is characterized by the last left somatic kinety (LKn) being shortened and none of the right somatic kineties extending to the anterior end of the cell, thus distinguishing it from all known pleurostomatid genera. The type species, Pseudolitonotus spirelis sp. n., is characterized by the possession of two macronuclear nodules, 11–15 right and 7–9 left kineties, a single contractile vacuole subterminally located, extrusomes evenly spaced along the entire ventral margin and some forming an “apical group”, two types of cortical granules, and the bottom of the oral slit invariably being twisted. Litonotus gracilis (Pan et al. Eur J Protistol 51:494–506, 2015) is believed to be another member of this new genus as its LKn and right somatic kineties are all shortened. Hence, a new combination, Pseudolitonotus gracilis (Pan et al., 2015) comb. n., is suggested and its diagnosis is improved. Molecular phylogenetic analyses based on SSU rDNA sequence data reveal that Pseudolitonotus gen. n. is monophyletic and groups with Apolitonotus (Pan et al. J Eukaryot Microbiol 67:252–262, 2020) of the family Protolitonotidae (Wu et al. Zool Scr 46:245–253, 2017). However, the familial assignment of this new genus is uncertain based on current data.
基金This study was supported by the Natural Science Foundation of China(project numbers:32070428,31872206).
文摘The morphology and infraciliature of the new hypotrichous ciliate,Oxytricha xianica sp.nov.,and a Chinese population of Oxytricha auripunctata Blatterer&Foissner,1988,are investigated using live observation and protargol staining.Oxytricha xianica sp.nov.is defined by the body size 85-130µm×30-50µm in vivo,the typical oxytrichid 18 frontoventral-transverse cirri,cortical granules absent,undulating membranes reduced or absent,three caudal cirri,dorsal kineties in Oxytricha pattern,and two ellipsoidal macronuclear nodules.The Chinese population of O.auripunctata differs slightly from other populations in the arrangement and color of cortical granules and position of anterior end of dorsal kinety 4.Phylogenetic analyses based on SSU-rDNA sequences support the assertion that O.auripunctata belongs to Oxytricha and Oxytrichidae.
基金This work was supported by the Natural Science Foundation of China(project number:31801984.31772440,31970486)the Fundamental Research Funds for the Central Universities(No.201762017).
文摘Zoothamnium is a speciose genus,most species of which have incomplete morphological data based on modern criteria.In the present study,the morphology of three species of Zoothamnium,i.e.,Z.apoarbuscula n.sp.,Z.apohentscheli n.sp.,and Z.alternans,collected in Qingdao,China,was revealed using living observation and silver staining.In addition,the SSU rDNA of each species was sequeneed for phylogenetic analyses.Zoothamnium apoarbuscula n.sp.is characterized by its umbellate colony which is up to 900 pm high,dichotomously branched stalk,differentiation of zooids,and infundibular polykinety 3 comprising three equal-length ciliary rows.Zoothamnium apohentscheli n.sp is characterized by its large colony up to 1700 pm high,alternately branched stalk,and infundibular polykinety 3 comprising three equal-length ciliary rows.A population of Z.altenums is described in detail.Phylogenetic analyses based on SSU rDNA sequence data revealed that species with an alternately branched stalk cluster together in gene trees and probably represent an independent lineage within the genus Zoothamnium.
基金supported by the National Natural Science Foundation of China(project number:41976086)the King Saud University,Saudi Arabia(Project No.RSP2022R7).
文摘Anaerobic protists in general,and ciliates in particular,are important components of anoxic or hypoxic environments,however,their diversity remains underestimated.Sonderia is a poorly studied genus that is distributed worldwide and is commonly found in anaerobic environments.In the present study,the taxonomy and phylogeny of three new species,namely Sonderia aposinuata sp.nov.,Sonderia paramacrochilus sp.nov.and Sonderia steini sp.nov.,collected from China,were investigated based on microscopic observations and SSU rRNA gene sequencing methods.Sonderia aposinuata sp.nov.is diagnosed mainly by having a relatively large body size,a crescent-shaped oral opening,numerous slender extrusomes,one suture on the ventral side and two on the dorsal side,and a buccal cavity that occupies the anterior third of the cell.Sonderia paramacrochilus sp.nov.closely resembles S.macrochilus but differs mainly by its oral opening being located closer to the anterior cell margin and its spindle-shaped extrusomes.Sonderia steini sp.nov.is a freshwater species that can be recognized by its shallow buccal cavity,sparsely distributed rod-shaped extrusomes,and having 68–79 monokinetidal somatic kineties that form sutures on both sides of the body.Phylogenetic analyses based on small subunit ribosomal RNA(SSU rRNA)gene sequence data support the monophyly of the family Sonderiidae,however,Sonderia is paraphyletic.The genus Sonderia is briefly revised and a key to the identification of species belonging to this genus is supplied.
基金supported by the Laoshan Laboratory(Project No.LSKJ202203201)the National Natural Science Foundation of China(Project No.32000300,32030015)+2 种基金the Natural Science Foundation of Shandong Province(Project No.ZR2022QC096)China Postdoctoral Science Foundation Grant(Project No.2022M711922)the Researchers Supporting Project(Project No.RSP 2025R7)King Saud University,Riyadh,Saudi Arabia.
文摘Aquaculture of red swamp crayfish Procambarus clarkii is an emerging farming industry in China.As shown recently,one of the most significant diseases affecting the red swamp crayfish is caused by overabundance of epibiotic peritrichs,a group of ciliated protists that are commonly found living as epibionts on aquatic animals.Nevertheless,few studies focusing on this issue have been performed.As part of a faunal study carried out in the Lake Weishan Wetland,China,four colonial sessilid peritrichs,namely Epicarchesium granulatum,Epistylis bimarginata,Epistylis semiciculus,and Zoothamnium procerius,attached to P.clarkii are documented.For each species,redescriptions and improved diagnoses are supplied.As a further aid to identification,14 new rDNA sequences of these four and a closely related species were obtained.In addition,as an aid for future studies on epibiotic ciliates,we supply a list and information about recent integrative studies that document the geographic distributions of related taxa.
基金This work was supported by The Natural Science Foundation of China(Project Nos.3167230&41076089)funded by the Research Group Project No.RGP-VPP-083,King Saud University Deanship of Scientific Research.
文摘Colonization features of biofilm-dwelling protozoa,especially ciliates,are routinely used as a useful tool for marine bioassessment.In this review,we summarize some of these features to develop an optimal sampling strategy for using biofilmdwelling protozoa as bioindicators of marine water quality.We focus on the utility of:(1)diversity in dices to analyze the colonizahon features of biofilm-dwelling protozoa for monitoring marine water quality;(2)MacArthur-Wilson and logistic equation models to determine spatio-temporal variations in colonization dynamics;and(3)homogeneity in taxonomic breadth of biofilm-dwelling protozoa during the process of colonization.The main findings are that:(1)the colonization dynamics of biofilm-dwelling protozoa are similar at depths of 1-5 m in spring and autumn;(2)temporal variability was well fitted to the MacArthur-Wilson and logistic models(P<0.05);and(3)species composition reached an equilibrium after a colonization period of 10-14 days in spring and autumn,but this took less time in the summer and more time in the winter.Ellipse-plotting tests demonstrated spatial variability in homogeneity in taxonomic structure of the ciiiate communities at different depths in the water column,with high levels at 1 m and 2 m and lower levels at 3.5 m and 5 m.Thus,the findings of this review suggest that the colonization dynamics of biofilin-dwelling protozoa may be influenced by different depths and seasons in coastal waters and 1-2 m in spring and autumn may be optimal sampling strategy for bioassessment on large spatial/temporal scales in marine ecosystems.
