Pub Date : 2022-08-09DOI: 10.1080/0269249X.2022.2096121
E. Reavie
This monograph contains descriptions of taxa from the diatom genera Craticula, Aneumastus, Decussiphycus, Cavinula, Lacustriella, Luticola, Mastogloia, Geissleria, Placoneis, Petroplacus, Navicula, Hippodonta, Sellaphora, Prestauroneis, Fallacia, Stauroneis, Brachysira, Anomoeoneis, Neidium, Diploneis, Caloneis, Pinnularia, Capartogramma, Frustulia, Amphipleura, Krasskella, Gyrosigma and Plagiotropis from periphytic and surface sediment samples in the coastal ecosystems of the Laurentian Great Lakes. Light micrographs are provided for diatom taxa recorded in 207 samples from 106 wetlands, embayments, high-energy and deep, nearshore locales of the five Great Lakes. 148 taxa are characterized, and 2 previously undescribed taxa are named. For 36 of the more common species, lake and habitat specificity, modelled optima for phosphorus and chloride and tolerance to coastal anthropogenic stressors are described.
{"title":"Symmetric biraphid diatoms (largely non-Navicula) from the Laurentian Great Lakes","authors":"E. Reavie","doi":"10.1080/0269249X.2022.2096121","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2096121","url":null,"abstract":"This monograph contains descriptions of taxa from the diatom genera Craticula, Aneumastus, Decussiphycus, Cavinula, Lacustriella, Luticola, Mastogloia, Geissleria, Placoneis, Petroplacus, Navicula, Hippodonta, Sellaphora, Prestauroneis, Fallacia, Stauroneis, Brachysira, Anomoeoneis, Neidium, Diploneis, Caloneis, Pinnularia, Capartogramma, Frustulia, Amphipleura, Krasskella, Gyrosigma and Plagiotropis from periphytic and surface sediment samples in the coastal ecosystems of the Laurentian Great Lakes. Light micrographs are provided for diatom taxa recorded in 207 samples from 106 wetlands, embayments, high-energy and deep, nearshore locales of the five Great Lakes. 148 taxa are characterized, and 2 previously undescribed taxa are named. For 36 of the more common species, lake and habitat specificity, modelled optima for phosphorus and chloride and tolerance to coastal anthropogenic stressors are described.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46034227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-03DOI: 10.1080/0269249X.2022.2134215
Mei Zhang, Ying Li, Tie-zhu Mi, F. Chen, Yu Zhen
Minutocellus polymorphus MMDL5290, a minute diatom, can efficiently utilize organic nitrogen (N) urea as the sole N source and achieve equivalent growth rate and photosynthesis capacity as it does with nitrate. Interestingly, M. polymorphus MMDL5290 growing on urea-replete (400 µM) medium yields a similar growth rate to that on nitrate-replete (882 µM). So far, very few reports are available on the molecular regulation mechanisms of microalgae with similar growth potential under different N sources. To address this gap, our study aimed to characterize the differences in transcriptome-level responses of M. polymorphus MMDL5290 between nitrate-replete and urea-replete conditions. We identified 4075 differentially expressed genes between these two groups. Interestingly, gene expression in light-harvesting, electron transport chain, ATP synthesis, and chlorophyll and carotenoid synthesis was up-regulated under urea, while the expression of carbon fixation genes did not change significantly. Meanwhile, transcriptome profiling indicated that under the urea-replete condition, M. polymorphus MMDL5290 triggered massive gene expression reconfiguration, inducing cells to increase investment in protein synthesis and antioxidative stress. This may explain why higher photosynthetic capacity in urea-grown cells does not lead to higher growth. Furthermore, down-regulation of PT (signal peptide) genes was observed under the urea-replete condition, suggesting a repressed capacity of phosphate transport. In addition, we identified 139 stably and highly expressed genes, which have the potential to be used as candidate reference genes in future gene expression studies on M. polymorphus MMDL5290.
{"title":"Transcriptomic reprogramming of diatom Minutocellus polymorphus grown on urea","authors":"Mei Zhang, Ying Li, Tie-zhu Mi, F. Chen, Yu Zhen","doi":"10.1080/0269249X.2022.2134215","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2134215","url":null,"abstract":"Minutocellus polymorphus MMDL5290, a minute diatom, can efficiently utilize organic nitrogen (N) urea as the sole N source and achieve equivalent growth rate and photosynthesis capacity as it does with nitrate. Interestingly, M. polymorphus MMDL5290 growing on urea-replete (400 µM) medium yields a similar growth rate to that on nitrate-replete (882 µM). So far, very few reports are available on the molecular regulation mechanisms of microalgae with similar growth potential under different N sources. To address this gap, our study aimed to characterize the differences in transcriptome-level responses of M. polymorphus MMDL5290 between nitrate-replete and urea-replete conditions. We identified 4075 differentially expressed genes between these two groups. Interestingly, gene expression in light-harvesting, electron transport chain, ATP synthesis, and chlorophyll and carotenoid synthesis was up-regulated under urea, while the expression of carbon fixation genes did not change significantly. Meanwhile, transcriptome profiling indicated that under the urea-replete condition, M. polymorphus MMDL5290 triggered massive gene expression reconfiguration, inducing cells to increase investment in protein synthesis and antioxidative stress. This may explain why higher photosynthetic capacity in urea-grown cells does not lead to higher growth. Furthermore, down-regulation of PT (signal peptide) genes was observed under the urea-replete condition, suggesting a repressed capacity of phosphate transport. In addition, we identified 139 stably and highly expressed genes, which have the potential to be used as candidate reference genes in future gene expression studies on M. polymorphus MMDL5290.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43472414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-03DOI: 10.1080/0269249X.2022.2118834
M. Enache, Marina G. Potapova, Meredith Tyree Polaskey, S. Spaulding
A new species of Aulacoseira Thwaites is described from sediment deposits of Surprise Lake, an isolated lake located in the New Jersey Highlands. The species is characterized by (1) a low mantle, (2) unevenly distributed mantle areolae of variable size and shape, and (3) a valve face covered by rounded areolae. The new species is most similar to Aulacoseira biseriata (Grunow in Van Heurk) Houk, R. Klee & H. Tanaka. Both taxa possess frustules with mantles that are low, with irregular pervalvar rows or scattered areolae. However, the two species differ in the shape and pattern of the areolae, the shape and structure of the mantle wall, the shape and depth of the ringleist, and other morphological features. In this study, we present light and scanning electron microscopic images of the new species and compare it to the most similar taxa.
{"title":"Aulacoseira newjerseyana sp. nov. (Bacillariophyta) a new freshwater centric diatom species from the northeastern USA","authors":"M. Enache, Marina G. Potapova, Meredith Tyree Polaskey, S. Spaulding","doi":"10.1080/0269249X.2022.2118834","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2118834","url":null,"abstract":"A new species of Aulacoseira Thwaites is described from sediment deposits of Surprise Lake, an isolated lake located in the New Jersey Highlands. The species is characterized by (1) a low mantle, (2) unevenly distributed mantle areolae of variable size and shape, and (3) a valve face covered by rounded areolae. The new species is most similar to Aulacoseira biseriata (Grunow in Van Heurk) Houk, R. Klee & H. Tanaka. Both taxa possess frustules with mantles that are low, with irregular pervalvar rows or scattered areolae. However, the two species differ in the shape and pattern of the areolae, the shape and structure of the mantle wall, the shape and depth of the ringleist, and other morphological features. In this study, we present light and scanning electron microscopic images of the new species and compare it to the most similar taxa.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41808867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-03DOI: 10.1080/0269249X.2022.2101545
Ekkachai Yana, Surakit Nakkaew, J. Pekkoh, Y. Peerapornpisal, A. Tuji, M. P. Davis, Matthew L. Julius, S. Mayama
The epilithic diatom Karthickia verestigmata Glushchenko et al. was described from North Viet Nam and Laos. Karthickia is a monotypic genus characterized by a unique ‘stigma’ located on the secondary side of the valve with an external circular opening and opening internally by two elongated slits. In 2012 we collected a diatom population consistent with the description of K. verestigmata from the Wang Kaew Waterfall on the upper Wang River in Doi Luang National Park, Thailand. This study details its internal ‘stigma’ structure utilizing sections made with a focused ion beam and observed with a scanning electron microscopy. From the bottom of external circular hole two narrowly flat spaces expanded from the bottom of the external opening down to each inner slit, lying in a trough that is a partial extension of a stria. A phylogenetic hypothesis for Karthickia was created using multiple genes. The taxonomic status of Karthickia is discussed in the context of other genera in the Cymbellales.
{"title":"Valve and ‘Stigma’ Structure and Phylogeny of an Enigmatic Cymbelloid Diatom Karthickia verestigmata Glushchenko, Kulikovskiy & Kociolek","authors":"Ekkachai Yana, Surakit Nakkaew, J. Pekkoh, Y. Peerapornpisal, A. Tuji, M. P. Davis, Matthew L. Julius, S. Mayama","doi":"10.1080/0269249X.2022.2101545","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2101545","url":null,"abstract":"The epilithic diatom Karthickia verestigmata Glushchenko et al. was described from North Viet Nam and Laos. Karthickia is a monotypic genus characterized by a unique ‘stigma’ located on the secondary side of the valve with an external circular opening and opening internally by two elongated slits. In 2012 we collected a diatom population consistent with the description of K. verestigmata from the Wang Kaew Waterfall on the upper Wang River in Doi Luang National Park, Thailand. This study details its internal ‘stigma’ structure utilizing sections made with a focused ion beam and observed with a scanning electron microscopy. From the bottom of external circular hole two narrowly flat spaces expanded from the bottom of the external opening down to each inner slit, lying in a trough that is a partial extension of a stria. A phylogenetic hypothesis for Karthickia was created using multiple genes. The taxonomic status of Karthickia is discussed in the context of other genera in the Cymbellales.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48583609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-03DOI: 10.1080/0269249X.2022.2130993
E. Masic, Dušica Zaova, S. Barudanović, Nadja Ognjanova-Rumenova, Z. Levkov
A new freshwater fossil diatom taxon Rimocostatus bugojnicus gen. et sp. nov, from Miocene sediments at the Gračanica site, Bugojno palaeolake in Bosnia and Herzegovina, is described. The main morphological feature of the genus is the presence of marginal rimoportulae with simple, round external openings positioned on interfascicles on the valve mantle and stalked, large, wide internal slits, positioned on every costa. Marginal and valve face fultoportulae are absent. With these characteristics, the species shows similarities to both marine and freshwater species, known from recent, and primarily from fossil, diatom deposits. Thus, Rimocostatus bugojnicus gen. et sp. nov. is an important find for understanding the evolution of centric diatom species.
{"title":"Rimocostatus bugojnicus gen.et. sp. nov. (Coscinodiscophyceae, Bacillariophyta) – a new fossil diatom genus from Gračanica, Bugojno palaeolake in Bosnia and Herzegovina","authors":"E. Masic, Dušica Zaova, S. Barudanović, Nadja Ognjanova-Rumenova, Z. Levkov","doi":"10.1080/0269249X.2022.2130993","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2130993","url":null,"abstract":"A new freshwater fossil diatom taxon Rimocostatus bugojnicus gen. et sp. nov, from Miocene sediments at the Gračanica site, Bugojno palaeolake in Bosnia and Herzegovina, is described. The main morphological feature of the genus is the presence of marginal rimoportulae with simple, round external openings positioned on interfascicles on the valve mantle and stalked, large, wide internal slits, positioned on every costa. Marginal and valve face fultoportulae are absent. With these characteristics, the species shows similarities to both marine and freshwater species, known from recent, and primarily from fossil, diatom deposits. Thus, Rimocostatus bugojnicus gen. et sp. nov. is an important find for understanding the evolution of centric diatom species.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45329818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-03DOI: 10.1080/0269249X.2022.2118835
K. Abe, D. Harwood, R. Jordan
Late Cretaceous (late Campanian) diatom assemblages from the Campbell Plateau (Zealandia), southwest Pacific Ocean, obtained from Deep Sea Drilling Project (DSDP) Leg 29 Site 275, contain well-preserved specimens of two enigmatic diatom species currently assigned to the genus Ktenodiscus; Micrampulla parvula originally described from the Maastrichtian-age Moreno Shale, California, and Pterotheca cretacea from DSDP Site 275. In general, the two species share a number of common features with modern Corethron (domed valves, probable heterovalvate frustules, T-shaped serrated articulated spines, marginal sockets), but differ in the location of the sockets (i.e. vertically at the base of the valve dome and not on the rim), the design of the spines and sockets, and the hollow structure extending from the valve centre. Although hooked spines are absent, equivalent 1-spine and 2-spine valves can be recognized in these two species. The recently described genus Praecorethron from the same late Campanian sediments shares many features with Micrampulla, but lacks the inflated central valve structure. As a result of our studies, the relevant subclass, order and family definitions are emended, as well as those of Micrampulla, M. parvula and M. cretacea comb. nov., and a new family, Micrampullaceae fam. nov., is erected to distinguish the ancient genera (Micrampulla and Praecorethron) from modern Corethron.
从深海钻探项目（DSDP）Leg 29 Site 275获得的西南太平洋坎贝尔高原（Zealandia）的晚白垩世（晚坎潘阶）硅藻组合，包含两种神秘硅藻物种的保存完好的标本，目前属于Ktenodicus属；Micrampulla parvula最初描述于马斯特里赫特时代加利福尼亚州莫雷诺页岩，以及DSDP 275号现场的Pterotheca cretacea。总的来说，这两个物种与现代Corestron有许多共同的特征（圆顶阀、可能的异阀形截头体、T形锯齿状关节棘、边缘球窝），但在球窝的位置（即垂直位于阀圆顶的底部而不是边缘）、棘和球窝的设计以及从阀中心延伸的中空结构方面有所不同。虽然没有钩状棘，但在这两个物种中可以识别出等效的1棘和2棘瓣。最近描述的Praecoretron属与Micrampulla有许多共同特征，但缺乏膨胀的中央阀结构。根据我们的研究结果，对相关的亚纲、目和科的定义进行了修订，并对Micrampulla、M.parvula和M.cretacea comb的亚纲，目和科进行了修订。11月，和一个新的科，Micrampullaceae fam。nov.，是为了区分古代属（Micrampulla和Praecoretron）和现代Corestron。
{"title":"Observations on Late Cretaceous Micrampulla (Corethrales, Bacillariophyceae) from the Campbell Plateau (Zealandia), southwest Pacific Ocean","authors":"K. Abe, D. Harwood, R. Jordan","doi":"10.1080/0269249X.2022.2118835","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2118835","url":null,"abstract":"Late Cretaceous (late Campanian) diatom assemblages from the Campbell Plateau (Zealandia), southwest Pacific Ocean, obtained from Deep Sea Drilling Project (DSDP) Leg 29 Site 275, contain well-preserved specimens of two enigmatic diatom species currently assigned to the genus Ktenodiscus; Micrampulla parvula originally described from the Maastrichtian-age Moreno Shale, California, and Pterotheca cretacea from DSDP Site 275. In general, the two species share a number of common features with modern Corethron (domed valves, probable heterovalvate frustules, T-shaped serrated articulated spines, marginal sockets), but differ in the location of the sockets (i.e. vertically at the base of the valve dome and not on the rim), the design of the spines and sockets, and the hollow structure extending from the valve centre. Although hooked spines are absent, equivalent 1-spine and 2-spine valves can be recognized in these two species. The recently described genus Praecorethron from the same late Campanian sediments shares many features with Micrampulla, but lacks the inflated central valve structure. As a result of our studies, the relevant subclass, order and family definitions are emended, as well as those of Micrampulla, M. parvula and M. cretacea comb. nov., and a new family, Micrampullaceae fam. nov., is erected to distinguish the ancient genera (Micrampulla and Praecorethron) from modern Corethron.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46087822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-03DOI: 10.1080/0269249X.2022.2100486
Pavel Beracko, Lucia Sochuliaková, J. Cíbik, T. Lánczos
Geographical location, landscape heterogeneity, and their position at the edge of Quaternary glaciations are the major reasons why the river basins of the Western Carpathians are of the utmost importance for research on European aquatic biodiversity. Moreover, unlike streams, springs have several features determining their insularity in the river continuum. This study aimed to uncover the mechanism forming the diatom assemblages in the karst springs environment, using a two-dimensional approach, including taxonomic and trait data. Thus, (1) the congruence between observed and expected values of null models of taxonomic/functional diversity and functional dispersion and (2) Generalized mixed models and Variation partitioning were used to assess how taxonomic/functional diversity and composition were associated with the local conditions, regional affiliation and spatial springs distance. In 64 rheocrene karst springs (10 karst mountain ranges) of the Western Carpathians, 138 epilithic diatom taxa were found. Null model analyses did not uncover any clear evidence of non-random events forming the spring diatom community. Although, the observed functional diversity did not differ from the null model for most springs, most observed values were lower than the mean value of the null model, suggesting that, except for random events, environmental filtering was an important driver of community assembly. Substratum type, spring connectivity and phosphorus concentration drove the value of taxonomic richness, whereas functional diversity was controlled by silica and bicarbonate concentration as well as spring size. In both models, affiliation to the mountain range (defined as a random factor) was significant. The Variation Partitioning Analysis showed that diatom assemblage composition was mainly determined by local and regional environmental conditions, whilst the distance between springs had only a weak influence.
{"title":"Drivers predicting biodiversity and community assembly of benthic diatoms in a karst spring environment","authors":"Pavel Beracko, Lucia Sochuliaková, J. Cíbik, T. Lánczos","doi":"10.1080/0269249X.2022.2100486","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2100486","url":null,"abstract":"Geographical location, landscape heterogeneity, and their position at the edge of Quaternary glaciations are the major reasons why the river basins of the Western Carpathians are of the utmost importance for research on European aquatic biodiversity. Moreover, unlike streams, springs have several features determining their insularity in the river continuum. This study aimed to uncover the mechanism forming the diatom assemblages in the karst springs environment, using a two-dimensional approach, including taxonomic and trait data. Thus, (1) the congruence between observed and expected values of null models of taxonomic/functional diversity and functional dispersion and (2) Generalized mixed models and Variation partitioning were used to assess how taxonomic/functional diversity and composition were associated with the local conditions, regional affiliation and spatial springs distance. In 64 rheocrene karst springs (10 karst mountain ranges) of the Western Carpathians, 138 epilithic diatom taxa were found. Null model analyses did not uncover any clear evidence of non-random events forming the spring diatom community. Although, the observed functional diversity did not differ from the null model for most springs, most observed values were lower than the mean value of the null model, suggesting that, except for random events, environmental filtering was an important driver of community assembly. Substratum type, spring connectivity and phosphorus concentration drove the value of taxonomic richness, whereas functional diversity was controlled by silica and bicarbonate concentration as well as spring size. In both models, affiliation to the mountain range (defined as a random factor) was significant. The Variation Partitioning Analysis showed that diatom assemblage composition was mainly determined by local and regional environmental conditions, whilst the distance between springs had only a weak influence.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46707048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-03DOI: 10.1080/0269249X.2022.2123049
A. Naseri, M. Noroozi, Y. Asri, A. Iranbakhsh, S. Saadatmand, E. Atazadeh
The taxonomic composition of the diatom flora of the Taleghan River and reservoir in Iran is described. The Taleghan River is one of the main tributaries of the Sepid Roud River, which is the second-longest river in Iran (∼ 670 km). Its headwaters are located in the Alborz Mountains in northwestern Iran and discharge into the Caspian Sea (North Iran). The current study was conducted from November 2017 to October 2018. A total of 167 taxa belonging to 49 genera and 27 families were identified. Nitzschia (28 spp.) Navicula (20 spp.), Cymbella (12 spp.), and Gomphonema (10 spp.) were the most abundant genera. The identified taxa can be classified as oligosaprobic to eutrophic and Canonical Correspondence Analysis (CCA) showed that temperature, NO3 2−, salinity, turbidity, EC, Si, and DO were the most significant environmental variables influencing diatom assemblages across seasons and sites in the river.
{"title":"Diatom taxonomy and environmental drivers of biodiversity in the Taleghan River and reservoir in Central Alborz, Iran","authors":"A. Naseri, M. Noroozi, Y. Asri, A. Iranbakhsh, S. Saadatmand, E. Atazadeh","doi":"10.1080/0269249X.2022.2123049","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2123049","url":null,"abstract":"The taxonomic composition of the diatom flora of the Taleghan River and reservoir in Iran is described. The Taleghan River is one of the main tributaries of the Sepid Roud River, which is the second-longest river in Iran (∼ 670 km). Its headwaters are located in the Alborz Mountains in northwestern Iran and discharge into the Caspian Sea (North Iran). The current study was conducted from November 2017 to October 2018. A total of 167 taxa belonging to 49 genera and 27 families were identified. Nitzschia (28 spp.) Navicula (20 spp.), Cymbella (12 spp.), and Gomphonema (10 spp.) were the most abundant genera. The identified taxa can be classified as oligosaprobic to eutrophic and Canonical Correspondence Analysis (CCA) showed that temperature, NO3 2−, salinity, turbidity, EC, Si, and DO were the most significant environmental variables influencing diatom assemblages across seasons and sites in the river.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47703157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-03DOI: 10.1080/0269249X.2022.2122576
A. A. Georgiev, M. Gololobova
The genus Shionodiscus (Thalassiosirales, Thalassiosiraceae) includes species that have strutted processes with long inward but reduced outward extensions, a labiate process typically located on the valve face, distant from the margin. Shionodiscus species inhabit the marine environment, and the genus includes both living and fossil species. In the course of our study of plankton samples from the Kara Sea, we found specimens belonging to Shionodiscus. Based on LM, SEM, and TEM investigations, a new species, Shionodiscus karianus sp. nov., is described. This species is distinguished from others in the genus based on areola densities, as well as the fine structure and location of the rimoportula and the central fultoportula and the ultrastructure of the areolae and cingulum. In this paper, we provide a morphological description of this taxon as well as a comparison with similar taxa. Previous records of Shionodiscus species in the Russian Arctic seas are discussed. Finally, we summarize and evaluate information on the important morphological characters, such as rimoportula position and fultoportula structure, for Shionodiscus.
{"title":"Shionodiscus karianus sp. nov. (Thalassiosirales, Thalassiosiraceae), a new planktonic diatom from the Kara Sea and notes on some morphological characters of Shionodiscus taxa","authors":"A. A. Georgiev, M. Gololobova","doi":"10.1080/0269249X.2022.2122576","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2122576","url":null,"abstract":"The genus Shionodiscus (Thalassiosirales, Thalassiosiraceae) includes species that have strutted processes with long inward but reduced outward extensions, a labiate process typically located on the valve face, distant from the margin. Shionodiscus species inhabit the marine environment, and the genus includes both living and fossil species. In the course of our study of plankton samples from the Kara Sea, we found specimens belonging to Shionodiscus. Based on LM, SEM, and TEM investigations, a new species, Shionodiscus karianus sp. nov., is described. This species is distinguished from others in the genus based on areola densities, as well as the fine structure and location of the rimoportula and the central fultoportula and the ultrastructure of the areolae and cingulum. In this paper, we provide a morphological description of this taxon as well as a comparison with similar taxa. Previous records of Shionodiscus species in the Russian Arctic seas are discussed. Finally, we summarize and evaluate information on the important morphological characters, such as rimoportula position and fultoportula structure, for Shionodiscus.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49464983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-28DOI: 10.1080/0269249x.2022.2078429
X. Benito, Melina Feitl, M. L. Carrevedo, M. Velez, J. Escobar, P. Tapia, M. Steinitz‐Kannan, S. Fritz
{"title":"Tropical South America Diatom Database: a tool for studying the macroecology of microorganisms","authors":"X. Benito, Melina Feitl, M. L. Carrevedo, M. Velez, J. Escobar, P. Tapia, M. Steinitz‐Kannan, S. Fritz","doi":"10.1080/0269249x.2022.2078429","DOIUrl":"https://doi.org/10.1080/0269249x.2022.2078429","url":null,"abstract":"","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48482953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：