Pub Date : 2025-04-11DOI: 10.1016/j.ejop.2025.126149
Jaroslav Kubín , Josef Juráň
This study brings the first information about the autecological traits of heterotrophic euglenoids at eighteen localities in South Bohemia (Czech Republic). A number of environmental and landscape parameters including water chemistry and diversity of algae as well as of heterotrophic protists were analyzed over two years in order to assess the effect of environmental parameters on heterotrophic euglenoids. The major diversity of osmotrophs was found in acidic wetlands (i.e., peat bogs), while the majority of phagotrophs were detected in polytrophic sites. This was also illustrated by the correlation of heterotrophic euglenoids with other groups of organisms and other biotic parameters related to the trophic level at the sampling sites. Apparently, habitats with well-developed macrovegetation harboured the highest alpha diversity of heterotrophic euglenoids. Noteworthy, most taxa were found during summer and fall. Additional ecological data on rarely reported taxa observed during this survey (Astasia lagenula var. maxima, Calycimonas quinquecarinata, Euglenopsis vacuolata, Heteronema proteus, Heteronema tremulum, Parmidium circulare) were provided as well.
{"title":"First contours of autecology of freshwater heterotrophic euglenoids – results of two-year research on 18 freshwater bodies","authors":"Jaroslav Kubín , Josef Juráň","doi":"10.1016/j.ejop.2025.126149","DOIUrl":"10.1016/j.ejop.2025.126149","url":null,"abstract":"<div><div>This study brings the first information about the autecological traits of heterotrophic euglenoids at eighteen localities in South Bohemia (Czech Republic). A number of environmental and landscape parameters including water chemistry and diversity of algae as well as of heterotrophic protists were analyzed over two years in order to assess the effect of environmental parameters on heterotrophic euglenoids. The major diversity of osmotrophs was found in acidic wetlands (i.e., peat bogs), while the majority of phagotrophs were detected in polytrophic sites. This was also illustrated by the correlation of heterotrophic euglenoids with other groups of organisms and other biotic parameters related to the trophic level at the sampling sites. Apparently, habitats with well-developed macrovegetation harboured the highest alpha diversity of heterotrophic euglenoids. Noteworthy, most taxa were found during summer and fall. Additional ecological data on rarely reported taxa observed during this survey (<em>Astasia lagenula</em> var. <em>maxima</em>, <em>Calycimonas quinquecarinata</em>, <em>Euglenopsis vacuolata</em>, <em>Heteronema proteus</em>, <em>Heteronema tremulum</em>, <em>Parmidium circulare</em>) were provided as well.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"99 ","pages":"Article 126149"},"PeriodicalIF":1.9,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-29DOI: 10.1016/j.ejop.2025.126147
Callum R.C. Evans , David A. Hatton , Graeme T. Swindles
The global nitrogen cycle has been majorly disrupted by anthropogenic activity. While nitrogen emissions in the UK and Ireland are declining, ammonia (NH3) remains a significant exception. NH3 emissions are mostly agriculturally sourced and deposited on nearby habitats at high rates in both countries. Peatlands are globally important wetlands that are vulnerable to NH3 deposition. Essential peatland restoration risks being diminished by excessive NH3 deposition, leading to the loss of valuable ecosystem services. This study investigates testate amoebae (indicators of contemporary and historic peatland conditions) as bioindicators of seasonal NH3 deposition on six peatlands across Northern Ireland, UK. Sphagnum, an NH3-sensitive bryophyte, was sampled adjacent to NH3 monitoring sites once per season for a year. When NH3 deposition was critically high, multivariate analysis demonstrates a link between NH3 and testate amoebae assemblage change. Similarly, at high NH3 deposition sites, testate amoebae taxa diversity is observed to be significantly reduced in springtime, when it is expected to be highest. Although, in response to high NH3 deposition large algivorous taxa do not proliferate as was anticipated, and mixotrophic taxa abundance decreases could not be linked primarily to NH3. This research demonstrates the continued potential of testate amoebae as highly informative peatland bioindicators.
{"title":"Testate amoebae are informative bioindicators of critically high ammonia deposition on peatlands","authors":"Callum R.C. Evans , David A. Hatton , Graeme T. Swindles","doi":"10.1016/j.ejop.2025.126147","DOIUrl":"10.1016/j.ejop.2025.126147","url":null,"abstract":"<div><div>The global nitrogen cycle has been majorly disrupted by anthropogenic activity. While nitrogen emissions in the UK and Ireland are declining, ammonia (NH<sub>3</sub>) remains a significant exception. NH<sub>3</sub> emissions are mostly agriculturally sourced and deposited on nearby habitats at high rates in both countries. Peatlands are globally important wetlands that are vulnerable to NH<sub>3</sub> deposition. Essential peatland restoration risks being diminished by excessive NH<sub>3</sub> deposition, leading to the loss of valuable ecosystem services. This study investigates testate amoebae (indicators of contemporary and historic peatland conditions) as bioindicators of seasonal NH<sub>3</sub> deposition on six peatlands across Northern Ireland, UK. <em>Sphagnum</em>, an NH<sub>3</sub>-sensitive bryophyte, was sampled adjacent to NH<sub>3</sub> monitoring sites once per season for a year. When NH<sub>3</sub> deposition was critically high, multivariate analysis demonstrates a link between NH<sub>3</sub> and testate amoebae assemblage change. Similarly, at high NH<sub>3</sub> deposition sites, testate amoebae taxa diversity is observed to be significantly reduced in springtime, when it is expected to be highest. Although, in response to high NH<sub>3</sub> deposition large algivorous taxa do not proliferate as was anticipated, and mixotrophic taxa abundance decreases could not be linked primarily to NH<sub>3</sub>. This research demonstrates the continued potential of testate amoebae as highly informative peatland bioindicators.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"99 ","pages":"Article 126147"},"PeriodicalIF":1.9,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143830306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-29DOI: 10.1016/j.ejop.2025.126148
Marcel Dominik Solbach , Ferry Siemensma , Maria Holzmann
In this study, we describe a novel monothalamous Foraminifera, discovered in shoreline sediment samples from the Southern Ocean. The individuals, approximately 75 μm in diameter, are relatively small for Foraminifera, mostly spherical, with an organic-walled test. Notably, these Foraminifera exhibit a unique behavior in culture: they surround themselves in planktonic diatoms, enabling them to float in the water column. This floating behavior is unusual for Foraminifera, which are often larger and possess a thick test made of calcite or agglutinated particles. We hypothesize that the small size of the organism, its lightweight organic test, and the habit of surrounding itself with centric diatoms may enable the floating behavior observed in culture and potentially aid dispersal in nature. Phylogenetic analysis of the 18S rDNA barcoding fragment places this undescribed organism as an independent lineage among monothalamid Foraminifera. We erect the novel genus Pensilisphaera with its type species Pensilisphaera antarcticaensis.
{"title":"A remarkable new monothalamid (Rhizaria, Foraminifera) from the shoreline of Livingston Island, Antarctica","authors":"Marcel Dominik Solbach , Ferry Siemensma , Maria Holzmann","doi":"10.1016/j.ejop.2025.126148","DOIUrl":"10.1016/j.ejop.2025.126148","url":null,"abstract":"<div><div>In this study, we describe a novel monothalamous Foraminifera, discovered in shoreline sediment samples from the Southern Ocean. The individuals, approximately 75 μm in diameter, are relatively small for Foraminifera, mostly spherical, with an organic-walled test. Notably, these Foraminifera exhibit a unique behavior in culture: they surround themselves in planktonic diatoms, enabling them to float in the water column. This floating behavior is unusual for Foraminifera, which are often larger and possess a thick test made of calcite or agglutinated particles. We hypothesize that the small size of the organism, its lightweight organic test, and the habit of surrounding itself with centric diatoms may enable the floating behavior observed in culture and potentially aid dispersal in nature. Phylogenetic analysis of the 18S rDNA barcoding fragment places this undescribed organism as an independent lineage among monothalamid Foraminifera. We erect the novel genus <em>Pensilisphaera</em> with its type species <em>Pensilisphaera antarcticaensis</em>.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"99 ","pages":"Article 126148"},"PeriodicalIF":1.9,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143767942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ciliates produce diffusible, cell-type-specific pheromones to regulate growth and mating. In Euplotes, these signaling molecules belong to species-specific families of disulfide-rich and structurally homologous proteins. Pheromones are co-dominantly expressed by genes in the somatic macronucleus (MAC), whereas their allelic diversity originates from the mating type locus in the germline micronucleus (MIC). During MAC development in sexual process, the MIC-derived diversity of specific alleles is rearranged via macronucleus-destined sequences (MDSs) assembly. While many MAC pheromones are well characterized, their MIC precursors and rearrangement process remain unknown. Here, we identified two MAC pheromone genes (mac-er-13/14) of E. raikovi, and two MIC regions (19 kb in total) containing 10 MDSs that assemble into mac-er-13. These MDSs are separated by internal eliminated sequences (234–3345 bp). The shortest MDSs (9–36 bp) encode the secreted region of pheromone, while longer MDSs (44–419 bp) encode other regions. Considering that the secreted regions show a higher sequence variation and the shorter MDSs have higher probability of alternative processing or imprecise assembly, we hypothesize that the high sequence variability of the macronuclear pheromone genes, which underlies the large number of mating types in E. raikovi, may result from alternative processing or imprecise assembly of these short MDSs.
{"title":"Characterization of the macronuclear and micronuclear pheromone genes of Euplotes raikovi reveals the origin of the mating type genetic diversity","authors":"Jianjun Huang , Ruitao Gong , Khaled A.S. Al-Rasheid , Feng Gao , Adriana Vallesi , Yaohan Jiang","doi":"10.1016/j.ejop.2025.126146","DOIUrl":"10.1016/j.ejop.2025.126146","url":null,"abstract":"<div><div>Ciliates produce diffusible, cell-type-specific pheromones to regulate growth and mating. In <em>Euplotes</em>, these signaling molecules belong to species-specific families of disulfide-rich and structurally homologous proteins. Pheromones are co-dominantly expressed by genes in the somatic macronucleus (MAC), whereas their allelic diversity originates from the <em>mating type locus</em> in the germline micronucleus (MIC). During MAC development in sexual process, the MIC-derived diversity of specific alleles is rearranged via macronucleus-destined sequences (MDSs) assembly. While many MAC pheromones are well characterized, their MIC precursors and rearrangement process remain unknown. Here, we identified two MAC pheromone genes (<em>mac-er-13/14</em>) of <em>E. raikovi</em>, and two MIC regions (19 kb in total) containing 10 MDSs that assemble into <em>mac-er-13</em>. These MDSs are separated by internal eliminated sequences (234–3345 bp). The shortest MDSs (9–36 bp) encode the secreted region of pheromone, while longer MDSs (44–419 bp) encode other regions. Considering that the secreted regions show a higher sequence variation and the shorter MDSs have higher probability of alternative processing or imprecise assembly, we hypothesize that the high sequence variability of the macronuclear pheromone genes, which underlies the large number of mating types in <em>E. raikovi</em>, may result from alternative processing or imprecise assembly of these short MDSs.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"99 ","pages":"Article 126146"},"PeriodicalIF":1.9,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-17DOI: 10.1016/j.ejop.2025.126142
Nanda Dwi Kristanti, Quoc Dung Nguyen, Mann Kyoon Shin
Recently, the interest in studying anaerobic ciliates, particularly armophorean ciliates of the family Metopidae, has increased. The genus Brachonella, a member of this family, currently comprises eight species. However, only four of them have been comprehensively described, with B. contorta, the type species of Brachonella, being the subject of extensive global distribution analyses. This study presents a comprehensive morphological and molecular phylogenetic analysis of B. tenuicauda nov. spec., B. elongata, and B. pulchra. Brachonella tenuicauda is characterized by a tail-like posterior body end and by clusters of two to four dikinetids in the preoral dome kineties. Brachonella elongata is identified by its slender, elongated body without posterior constriction, whereas B. pulchra shows a broadly ellipsoidal to nearly obovoid body. Korean populations of B. pulchra and B. tenuicauda exhibit a diplostichomonad paroral membrane, a feature not previously documented for this genus. Phylogenetic analysis of 18S rDNA sequences indicates non-monophyly of the family Metopidae. Conversely, the genus Brachonella is depicted as monophyletic with full support, confirming its molecular distinctness from other metopid genera.
{"title":"Exploring the diversity of Brachonella: Morphological and molecular analysis with the discovery of a new species, Brachonella tenuicauda nov. spec. (Ciliophora, Armophorea, Metopida)","authors":"Nanda Dwi Kristanti, Quoc Dung Nguyen, Mann Kyoon Shin","doi":"10.1016/j.ejop.2025.126142","DOIUrl":"10.1016/j.ejop.2025.126142","url":null,"abstract":"<div><div>Recently, the interest in studying anaerobic ciliates, particularly armophorean ciliates of the family Metopidae, has increased. The genus <em>Brachonella</em>, a member of this family, currently comprises eight species. However, only four of them have been comprehensively described, with <em>B. contorta</em>, the type species of <em>Brachonella</em>, being the subject of extensive global distribution analyses. This study presents a comprehensive morphological and molecular phylogenetic analysis of <em>B. tenuicauda</em> nov. spec., <em>B. elongata</em>, and <em>B. pulchra. Brachonella tenuicauda</em> is characterized by a tail-like posterior body end and by clusters of two to four dikinetids in the preoral dome kineties. <em>Brachonella elongata</em> is identified by its slender, elongated body without posterior constriction, whereas <em>B. pulchra</em> shows a broadly ellipsoidal to nearly obovoid body. Korean populations of <em>B. pulchra</em> and <em>B. tenuicauda</em> exhibit a diplostichomonad paroral membrane, a feature not previously documented for this genus. Phylogenetic analysis of 18S rDNA sequences indicates non-monophyly of the family Metopidae. Conversely, the genus <em>Brachonella</em> is depicted as monophyletic with full support, confirming its molecular distinctness from other metopid genera.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"99 ","pages":"Article 126142"},"PeriodicalIF":1.9,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-07DOI: 10.1016/j.ejop.2025.126140
Renate Radek , Janneke Hassler , Katja Platt , Hisar Ahmad , Thomas Fromm , Michaela Strüder-Kypke , David Sillam-Dussès , Jiří Synek , Jan Šobotník , Vincent Hervé , Andreas Brune
Sessilids (Oligohymenophorea, Peritrichia, Sessilida) reportedly colonize the gut of certain “higher termites” (family Termitidae), but only a single species, Termitophrya africana from Jugositermes tuberculatus (subfamily Apicotermitinae), has been described based on a drawing. Similar ciliates were observed in other Apicotermitinae but remained unspecified. Our SSU rRNA gene-based survey of peritrich ciliates in a broad range of Termitidae recovered distinct phylotypes from several Apicotermitinae (Astalotermes, Jugositermes, and Phoxotermes), albeit only from samples collected in Cameroon and not from all species of these genera. They form a monophyletic group in the family Epistylididae (Sessilida), with Orborhabdostyla bromelicola as the closest relative. Light, scanning, and transmission electron microscopy of the sessilid ciliates in J. tuberculatus revealed two morphotypes, which were assigned to their corresponding phylotypes by sequence analysis of capillary-picked single cells. One morphotype, which is highly contractile and broadens continuously towards the posterior end, matches the description of Termitophrya africana. The cells are attached by a posterior scopula with short cilia and are often covered with rod-shaped ectobionts. The other morphotype has a stockier, barrel-shaped body and a short, clearly demarcated anterior end and is always free of ectobionts. We designate it as Doliophrys denislynni gen. nov., sp. nov.
{"title":"Phylogeny, morphology, and ultrastructure of sessilid peritrich ciliates in termite guts, Termitophrya africana and Doliophrys denislynni gen. nov., sp. nov.","authors":"Renate Radek , Janneke Hassler , Katja Platt , Hisar Ahmad , Thomas Fromm , Michaela Strüder-Kypke , David Sillam-Dussès , Jiří Synek , Jan Šobotník , Vincent Hervé , Andreas Brune","doi":"10.1016/j.ejop.2025.126140","DOIUrl":"10.1016/j.ejop.2025.126140","url":null,"abstract":"<div><div>Sessilids (Oligohymenophorea, Peritrichia, Sessilida) reportedly colonize the gut of certain “higher termites” (family Termitidae), but only a single species, <em>Termitophrya africana</em> from <em>Jugositermes tuberculatus</em> (subfamily Apicotermitinae), has been described based on a drawing. Similar ciliates were observed in other Apicotermitinae but remained unspecified<em>.</em> Our SSU rRNA gene-based survey of peritrich ciliates in a broad range of Termitidae recovered distinct phylotypes from several Apicotermitinae (<em>Astalotermes</em>, <em>Jugositermes</em>, and <em>Phoxotermes</em>), albeit only from samples collected in Cameroon and not from all species of these genera. They form a monophyletic group in the family Epistylididae (Sessilida), with <em>Orborhabdostyla bromelicola</em> as the closest relative. Light, scanning, and transmission electron microscopy of the sessilid ciliates in <em>J. tuberculatus</em> revealed two morphotypes, which were assigned to their corresponding phylotypes by sequence analysis of capillary-picked single cells. One morphotype, which is highly contractile and broadens continuously towards the posterior end, matches the description of <em>Termitophrya africana</em>. The cells are attached by a posterior scopula with short cilia and are often covered with rod-shaped ectobionts. The other morphotype has a stockier, barrel-shaped body and a short, clearly demarcated anterior end and is always free of ectobionts. We designate it as <em>Doliophrys denislynni</em> gen. nov., sp. nov.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"99 ","pages":"Article 126140"},"PeriodicalIF":1.9,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-04DOI: 10.1016/j.ejop.2025.126139
Alexander Kudryavtsev , Mikhail Krendelev, Ekaterina Piven, Ekaterina Volkova
A tiny amoebozoan with a locomotive size of about 10 μm was isolated from an inland brackish water biotope in the northwest of Russia. During locomotion, amoebae were flattened, with broad anterior hyaloplasm and short ventral subpseudopodia that appeared like small bumps. Electron microscopy shows that amoebae are enclosed in a flexible layer of flat oval scales embedded in a matrix and separated from the plasma membrane surface. These characters are in accordance with the phylogenetic placement of this strain, as reconstructed using the nuclear SSU rRNA, actin, and mitochondrial cytochrome c oxidase subunit 1 (Cox1) gene sequences. Morphology and molecular phylogenies warrant the description of the studied strain as a new species, Armaparvus browni sp. nov. This species shows a broad range of salinity tolerance, being able to reproduce in culture under salinity of 2.5 ‰, but not in 0.3 ‰ or artificial freshwater medium. This may be due to an adaptation to brackish water with oscillating salinity and hence A. browni probably cannot expand into truly freshwater habitats.
{"title":"Armaparvus browni sp. nov. (Amoebozoa, Cutosea) isolated from an inland brackish water biotope","authors":"Alexander Kudryavtsev , Mikhail Krendelev, Ekaterina Piven, Ekaterina Volkova","doi":"10.1016/j.ejop.2025.126139","DOIUrl":"10.1016/j.ejop.2025.126139","url":null,"abstract":"<div><div>A tiny amoebozoan with a locomotive size of about 10 μm was isolated from an inland brackish water biotope in the northwest of Russia. During locomotion, amoebae were flattened, with broad anterior hyaloplasm and short ventral subpseudopodia that appeared like small bumps. Electron microscopy shows that amoebae are enclosed in a flexible layer of flat oval scales embedded in a matrix and separated from the plasma membrane surface. These characters are in accordance with the phylogenetic placement of this strain, as reconstructed using the nuclear SSU rRNA, actin, and mitochondrial cytochrome <em>c</em> oxidase subunit 1 (Cox1) gene sequences. Morphology and molecular phylogenies warrant the description of the studied strain as a new species, <em>Armaparvus browni</em> sp. nov. This species shows a broad range of salinity tolerance, being able to reproduce in culture under salinity of 2.5 ‰, but not in 0.3 ‰ or artificial freshwater medium. This may be due to an adaptation to brackish water with oscillating salinity and hence <em>A. browni</em> probably cannot expand into truly freshwater habitats.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"98 ","pages":"Article 126139"},"PeriodicalIF":1.9,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-02DOI: 10.1016/j.ejop.2025.126141
Miaomiao Wang, Tao Hu, Shanshan Wang, Zhangwen Tong, Qianqian Wei, Xinpeng Fan
The morphology, morphogenesis, and molecular phylogeny of a new hypotrichous ciliate, Sterkiella zhangi n. sp., which originated from terrestrial moss collected in east China, were studied using live observation, protargol staining, and the macronuclear SSU rRNA and mitochondrial cytochrome c oxidase subunit 1 gene sequences. The new species can be distinguished from its congeners by the following characteristics: three ordinary frontal cirri (an extra small frontal cirrus present in half of the individuals examined), an average of 15 left and 16 right marginal cirri, five transverse cirri, two macronuclear nodules, and cyst surface with irregular wrinkles but without spines. The 1:3:3:3:4:4 frontal-ventral-transverse anlagen fragmentation pattern of S. zhangi n. sp. indicates that the extra frontal cirrus is very likely a retained parental structure. Phylogenetic analyses revealed that the new species branches early in the subfamily Stylonychinae. The comparison of mitochondrial cytochrome c oxidase subunit 1 gene sequences of Sterkiella species shows that the intra-specific variation is much smaller than the inter-specific divergence. The well-known model organism Oxytricha trifallax has accumulated significant evolutionary differences and should be treated as a distinct species rather than a synonym of S. histriomuscorum.
采用活体观察、原甲酚染色、大核SSU rRNA和线粒体细胞色素c氧化酶亚单位1基因序列等方法，研究了产于中国东部陆生苔藓中的下富集纤毛虫新种Sterkiella zhangi n. sp.的形态、形态发生和分子系统发育。该新品种可通过以下特征与其同类区分开来：3 个普通额圈（半数个体有一个额外的小额圈）、平均 15 个左侧和 16 个右侧边缘圈、5 个横向圈、2 个巨核结节、囊肿表面有不规则皱纹但无棘刺。张氏囊藻 1:3:3:3:4:4 的额面-腹面-横面原基分裂模式表明，额外的额面卷须很可能是保留下来的亲本结构。系统进化分析表明，该新种在石龙子亚科中分支较早。通过比较 Sterkiella 的线粒体细胞色素 c 氧化酶亚单位 1 基因序列发现，种内变异远远小于种间差异。众所周知的模式生物 Oxytricha trifallax 在进化过程中积累了显著的差异，应将其作为一个独立的物种而不是 S. histriomuscorum 的异名。
{"title":"Morphology and molecular phylogeny of a new hypotrichous ciliate, Sterkiella zhangi n. sp. (Ciliophora, Oxytrichidae)","authors":"Miaomiao Wang, Tao Hu, Shanshan Wang, Zhangwen Tong, Qianqian Wei, Xinpeng Fan","doi":"10.1016/j.ejop.2025.126141","DOIUrl":"10.1016/j.ejop.2025.126141","url":null,"abstract":"<div><div>The morphology, morphogenesis, and molecular phylogeny of a new hypotrichous ciliate, <em>Sterkiella zhangi</em> n. sp., which originated from terrestrial moss collected in east China, were studied using live observation, protargol staining, and the macronuclear SSU rRNA and mitochondrial cytochrome <em>c</em> oxidase subunit 1 gene sequences. The new species can be distinguished from its congeners by the following characteristics: three ordinary frontal cirri (an extra small frontal cirrus present in half of the individuals examined), an average of 15 left and 16 right marginal cirri, five transverse cirri, two macronuclear nodules, and cyst surface with irregular wrinkles but without spines. The 1:3:3:3:4:4 frontal-ventral-transverse anlagen fragmentation pattern of <em>S. zhangi</em> n. sp. indicates that the extra frontal cirrus is very likely a retained parental structure. Phylogenetic analyses revealed that the new species branches early in the subfamily Stylonychinae. The comparison of mitochondrial cytochrome <em>c</em> oxidase subunit 1 gene sequences of <em>Sterkiella</em> species shows that the intra-specific variation is much smaller than the inter-specific divergence. The well-known model organism <em>Oxytricha trifallax</em> has accumulated significant evolutionary differences and should be treated as a distinct species rather than a synonym of <em>S. histriomuscorum</em>.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"98 ","pages":"Article 126141"},"PeriodicalIF":1.9,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-22DOI: 10.1016/j.ejop.2025.126138
Lijian Liao , Abdul Ghaffar , Xiaozhong Hu
The morphology and morphogenesis of a new Stichotrichida species, Heterodeviata longa nov. spec., isolated from a brackish water habitat in Qingdao, China, were investigated using live observation and the protargol staining method. The new species is morphologically distinguished by possessing one buccal, three to five parabuccal and three frontal cirri, one long frontoventral row of ca. 12 cirri extending beyond mid-body, four left and two right marginal cirral rows, and two dorsal kineties: (1) left dorsal kinety bipolar, comprising 16–23 dikinetids, and with one to three caudal cirri at its rear end, while (2) right dorsal kinety comprising only two dikinetids. During morphogenesis, four frontal-ventral cirral anlagen form both in the proter and the opisthe. The parental adoral zone of membranelles remains intact and is completely inherited by the proter. The anlagen for marginal rows and the left dorsal kinety develop intrakinetally. The right dorsal kinety is generated dorsomarginally. The 18S rRNA gene sequence of the new species has a similarity of 99.6 % and 98.1 % with two other congeners. Phylogenetic analysis supported their close relationship and the monophyly of the genus Heterodeviata.
采用活体观察和原targol染色法，对青岛某咸水生境中一新种尾毛虫（Heterodeviata longa nov. spec）的形态和形态发生进行了研究。该新种在形态上具有1个颊卷、3至5个颊旁卷和3个额卷，1个长额腹排约12个卷，延伸至身体中部，4个左边缘卷和2个右边缘卷，以及2个背侧运动：(1)左背运动双极性，包括16-23个双动体，并在其尾部有1至3个尾卷，而(2)右背运动仅包括2个双动体。在形态发生过程中，蛋白和视肌均形成四种额-腹侧环状胶原。亲本膜片区保持完整，并完全由蛋白遗传。边缘行和左背肌的角原是相互作用的。右背运动是由背侧产生的。新种的18S rRNA基因序列与其他两个同系物的相似性分别为99.6%和98.1%。系统发育分析支持了它们的亲缘关系和异种属的单系性。
{"title":"Morphology, morphogenesis, and molecular phylogeny of a new brackish water ciliate, Heterodeviata longa nov. spec. (Ciliophora, Hypotrichia)","authors":"Lijian Liao , Abdul Ghaffar , Xiaozhong Hu","doi":"10.1016/j.ejop.2025.126138","DOIUrl":"10.1016/j.ejop.2025.126138","url":null,"abstract":"<div><div>The morphology and morphogenesis of a new Stichotrichida species, <em>Heterodeviata longa</em> nov. spec., isolated from a brackish water habitat in Qingdao, China, were investigated using live observation and the protargol staining method. The new species is morphologically distinguished by possessing one buccal, three to five parabuccal and three frontal cirri, one long frontoventral row of ca. 12 cirri extending beyond mid-body, four left and two right marginal cirral rows, and two dorsal kineties: (1) left dorsal kinety bipolar, comprising 16–23 dikinetids, and with one to three caudal cirri at its rear end, while (2) right dorsal kinety comprising only two dikinetids. During morphogenesis, four frontal-ventral cirral anlagen form both in the proter and the opisthe. The parental adoral zone of membranelles remains intact and is completely inherited by the proter. The anlagen for marginal rows and the left dorsal kinety develop intrakinetally. The right dorsal kinety is generated dorsomarginally. The 18S rRNA gene sequence of the new species has a similarity of 99.6 % and 98.1 % with two other congeners. Phylogenetic analysis supported their close relationship and the monophyly of the genus <em>Heterodeviata</em>.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"98 ","pages":"Article 126138"},"PeriodicalIF":1.9,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143627934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.ejop.2025.126134
Arbaz Rehman , Jing Wang , Hao Yue , Xiuhong Zhang , Zelong Li
Diatom blooms are a global ecological perturbation that releases algal organic matter (AOM), significantly affecting coastal ecosystems by altering microbial community dynamics. AOM, derived from algal cell lysis, may serve as a nutrient source influencing protistan communities. However, the effects of AOM on protistan ecology, including the community structure and assembly processes, remain largely unexplored in coastal sediments. In this study, we investigated the impact of AOM on the protistan community structure using macrogenomic analysis and high-throughput sequencing. The results revealed significant shifts in the protistan diversity (alpha and beta diversity) and community composition. Phototrophs and consumers were the primary functional groups affected, with their relative abundances significantly regulated by AOM, highlighting its functional-level impacts. Moreover, AOM influenced also the protistan community assembly, increasing the proportion of deterministic processes and altering the dynamic succession within the protistan co-occurrence network. Diatom blooms act as ecological filters, reducing diversity while promoting the dominance of specific functional groups. This study bridges the gap in understanding the AOM's role in shaping the ecological succession of protists in coastal sediments, offering valuable insights into the broader ecological impact of marine diatom blooms.
{"title":"Algal organic matter alters protistan community structure and assembly processes in coastal sediments","authors":"Arbaz Rehman , Jing Wang , Hao Yue , Xiuhong Zhang , Zelong Li","doi":"10.1016/j.ejop.2025.126134","DOIUrl":"10.1016/j.ejop.2025.126134","url":null,"abstract":"<div><div>Diatom blooms are a global ecological perturbation that releases algal organic matter (AOM), significantly affecting coastal ecosystems by altering microbial community dynamics. AOM, derived from algal cell lysis, may serve as a nutrient source influencing protistan communities. However, the effects of AOM on protistan ecology, including the community structure and assembly processes, remain largely unexplored in coastal sediments. In this study, we investigated the impact of AOM on the protistan community structure using macrogenomic analysis and high-throughput sequencing. The results revealed significant shifts in the protistan diversity (alpha and beta diversity) and community composition. Phototrophs and consumers were the primary functional groups affected, with their relative abundances significantly regulated by AOM, highlighting its functional-level impacts. Moreover, AOM influenced also the protistan community assembly, increasing the proportion of deterministic processes and altering the dynamic succession within the protistan co-occurrence network. Diatom blooms act as ecological filters, reducing diversity while promoting the dominance of specific functional groups. This study bridges the gap in understanding the AOM's role in shaping the ecological succession of protists in coastal sediments, offering valuable insights into the broader ecological impact of marine diatom blooms.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"97 ","pages":"Article 126134"},"PeriodicalIF":1.9,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143058582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号