Diatom Taxonomy and Ecology Research Papers (original) (raw)
2025
Se estudiaron las diatomeas epilíticas y las condiciones fisicoquímicas del agua en el río Tapartó Andes, Colombia. El perifiton se colectó en cuatro campañas de muestreo, en tres estaciones del río: parta alta, media y baja. El material... more
Se estudiaron las diatomeas epilíticas y las condiciones fisicoquímicas del agua en el río Tapartó Andes, Colombia. El perifiton se colectó en cuatro campañas de muestreo, en tres estaciones del río: parta alta, media y baja. El material fue tratado con peróxido caliente y se prepararon muestras en Naphrax para observación al microscopio óptico y al microscopio electrónico. Se identificaron 49 especies de diatomeas, se reportan por primera vez para Colombia las especies Amphipleura chiapasensis, Cymbella cf. ehrenbergii, Encyonema minutiforme, Encyonema silesiacum, Pseudostaurosira aff. americana, Pseudostaurosira medliniae, Surirella bryophila, además se registran las condiciones fisicoquímicas en las que se encuentran las diatomeas. Esta información es importante para incorporarla dentro de métodos de monitoreo biológico que emplean las diatomeas y sus valores de bioindicación. Con este trabajo se aumenta el conocimiento en la distribución de las diatomeas en el país y de las condiciones fisicoquímicas a las que se pueden asociar.
2025, Asian Journal of Basic Science & Research
Anthropogenic activities more and more degrade wetlands. The management of these wetlands involves analyzing the ecological quality of the water. Diatoms constitute a biological marker widely used in the assessment of waters. The... more
Anthropogenic activities more and more degrade wetlands. The management of these wetlands involves analyzing the ecological quality of the water. Diatoms constitute a biological marker widely used in the assessment of waters. The objective of the study was to determine the water quality of the Nkwen rivers by diatom index with a view to their sustainable management. The study took place in 3 rivers from July 2023 to June 2024. Periphytic diatoms were sampled in these rivers by scraping and taken to the laboratory for analysis. It emerged that river 1 was of average quality with an index of 5.11. River 2 was of poor ecological quality with an index of 5.62. River 3 was of very good ecological quality with an index of 2.17. Measures should be taken by public authorities and the council to restore the degraded river 2 and monitor these watercourses using ecological methods by Diatoms to maintain the balance of these hydro-systems.
2025
In this work, the assessment of the ecological status of the Oum Er-rabie River basin was carried out by determining the physical-chemical, bacteriological and biological parameters. sampling Benthic macroinvertebrates and water were... more
In this work, the assessment of the ecological status of the Oum Er-rabie River basin was carried out by determining the physical-chemical, bacteriological and biological parameters. sampling Benthic macroinvertebrates and water were collected only once during the fourth seasons at the 31 stations upstream to downstream of the streams from spring 2018 to winter 2019. Physical-chemical quality was assessed from the Weighted Index (IP) based on 16 parameters (temperature, conductivity, dissolved oxygen, nitrate, nitrites, Ammonium, biochemical oxygen demand, chemical oxygen demand, turbidity, ortho phosphate, calcium, magnesium, chloride, sulphate) and revealed an average to very poor quality in most stations. The microbiological quality, based on the assessment of the three parameters: fecal coliforms, total coliforms and fecal streptococcus, varies between, good and bad. The values of the biotic indices, Iberian Biological Monitoring Working Group Index (IBMWP), River Habitat Index (IHF) and River Quality Index (QBR), classify the waters of the various prospected stations as good quality waters for upstream stations (S2, S10, S12, S14, S15, S16) and in the medium to very bad quality category for other localities except for two stations (S27, S30) which are downstream but have good qualities.
2025, International journal of innovation and scientific research
The anarchic and rampant human impact in the city of Douala is the cause of the deterioration of its wetlands. The overall objective of the study is to determine the water quality of Kambo and Longmayagui rivers of Douala located in... more
The anarchic and rampant human impact in the city of Douala is the cause of the deterioration of its wetlands. The overall objective of the study is to determine the water quality of Kambo and Longmayagui rivers of Douala located in periurban and urban center respectively from Diatoms indexes. Organic materials and stones were sampled in each river. A total of 43 species belonging to 9 families and 22 genera were identified. The Diatom index is 4.0 to Kambo river (site 1) and 6.9 to Longmayagui river (site 2). These indexes show that Kambo river is less polluted, while Longmayagui river is polluted. The most frequent and abundant Diatoms in the samples of the two streams, Batika river characteristics (control) and Kambo can be used as indicators of unpolluted environment. These are :
2025, Georgia journal of science
Algal assemblages were evaluated at two Southeastern U.S. streams with reduced human impact, Upper Three Runs Creek and Tobbler Creek. The two sites were collected using standard protocols for stream samplings. The algal community was... more
Algal assemblages were evaluated at two Southeastern U.S. streams with reduced human impact, Upper Three Runs Creek and Tobbler Creek. The two sites were collected using standard protocols for stream samplings. The algal community was dominated by diatoms. Community attributes were found to be similar between the two sites, while indicator species varied as determined by Trophic Diatom Index values and the percentage of tolerant taxa to pollutants. Low pH tolerant Eunotia species were dominant in Upper Three Runs Creek while pH neutral, mesotrophic species were dominant in Tobbler Creek. This is the first report on primary producers from both sites and a taxonomic evaluation of the more common taxa is given for future reference.
2025, Phytotaxa
Three new needle-shaped Fragilaria species from freshwater lake Apastepeque in El Salvador (Fragilaria salvadoriana sp. nov., F. maarensis sp. nov.) and subsaline lake Nam Co on the Tibetan Plateau (F. huebeneri sp. nov.) are described... more
Three new needle-shaped Fragilaria species from freshwater lake Apastepeque in El Salvador (Fragilaria salvadoriana sp. nov., F. maarensis sp. nov.) and subsaline lake Nam Co on the Tibetan Plateau (F. huebeneri sp. nov.) are described and compared based on light and scanning electron microscopy observations and morphometric analyses. Fragilaria salvadoriana sp. nov. is characterized by narrowly linear-lanceolate, sometimes centrally constricted valves, subcapitate to rarely capitate apices, and a distinct, dented appearing central area. Striae are composed of 2−5 occluded areolae. It can be differentiated from similar needle-shaped species by the valve outline, relatively low striae density, and shark fin-shaped spines. Characteristic of F. maarensis sp. nov. are a very narrowly lanceolate valve outline and subcapitate apices. The apical pore field is composed of 2–3 rows of poroids and acute, irregularly oriented spines are present at the junction between valve face and mantle. Th...
2025, Pollution
Actions to monitor, restore, protect, and utilize water ecosystems require adequate understanding and knowledge of the freshwater body's biological community structure and water quality . As such, biological components alongside... more
Actions to monitor, restore, protect, and utilize water ecosystems require adequate understanding and knowledge of the freshwater body's biological community structure and water quality . As such, biological components alongside physicochemical parameters are used to assess water quality and give insights to ecological status . Biological components such as diatoms are great tools to utilize to reach water quality assessment and monitoring goals. Diatoms are algae that have quick generation times and are sensitive to environmental changes. This allows them to become indicators of pollution in freshwater bodies and be used for freshwater biomonitoring . Diatom-based indices were developed to utilize the diatom's generally cosmopolitan distribution and robust relationship to nutrient and environmental variables
2025
Actions to monitor, restore, protect, and utilize water ecosystems require adequate understanding and knowledge of the freshwater body's biological community structure and water quality . As such, biological components alongside... more
Actions to monitor, restore, protect, and utilize water ecosystems require adequate understanding and knowledge of the freshwater body's biological community structure and water quality . As such, biological components alongside physicochemical parameters are used to assess water quality and give insights to ecological status . Biological components such as diatoms are great tools to utilize to reach water quality assessment and monitoring goals. Diatoms are algae that have quick generation times and are sensitive to environmental changes. This allows them to become indicators of pollution in freshwater bodies and be used for freshwater biomonitoring . Diatom-based indices were developed to utilize the diatom's generally cosmopolitan distribution and robust relationship to nutrient and environmental variables
2025, Boletín de Investigaciones Marinas y Costeras
The marine mucilaginous tube-forming benthic diatoms Berkeleya hyalina (Round et Brooks) Cox and Parlibellus berkeleyi (Kütz.) Cox are reported for the fist time for the Caribbean coast of Colombian, in Santa Marta area. These two species... more
The marine mucilaginous tube-forming benthic diatoms Berkeleya hyalina (Round et Brooks) Cox and Parlibellus berkeleyi (Kütz.) Cox are reported for the fist time for the Caribbean coast of Colombian, in Santa Marta area. These two species were found infrequently growing as macroscopic colonies inhabiting shallow rocky substrata. The report of P. berkeleyi species is the fist for the Caribbean Sea.
2025, Revista Mexicana de Biodiversidad
We investigated the structure and diversity of diatoms in communities of metaphyton and periphyton from the wetland of El Edén Ecological Reserve, Quintana Roo, Mexico. In spite of the close association and communication between these... more
We investigated the structure and diversity of diatoms in communities of metaphyton and periphyton from the wetland of El Edén Ecological Reserve, Quintana Roo, Mexico. In spite of the close association and communication between these communities, our comparisons reveal that the 2 communities have distinct species assemblages, with the periphyton being more diverse overall. We fi t abundance curves for periphyton and metaphyton, and argue that our results are consistent with communities where environmental conditions play a more important role than competition in structuring diatom species assemblages.
2025, Acta Botanica Croatica
A new Amphora species, Amphora soninkhishigae sp. nov. is described from the saline lakes, Oigon Nuur and Uvs Nuur, in western Mongolia. Amphora soninkhishigae is characterized by its small size (valves 12-28 mm long, 2.9-3.8 mm wide),... more
A new Amphora species, Amphora soninkhishigae sp. nov. is described from the saline lakes, Oigon Nuur and Uvs Nuur, in western Mongolia. Amphora soninkhishigae is characterized by its small size (valves 12-28 mm long, 2.9-3.8 mm wide), fine ornamentation, and a broad, internally thickened central area on the dorsal side of the valve (dorsal stauros) that branches along the dorsal margin. Among the amphoroid diatoms, Amphora soninkhishigae belongs in the subgenus Oxyamphora Cleve, where it is allied with other small Amphora taxa bearing a dorsal stauros including Amphora staurophora Juhlin--Dannfelt, Amphora abludans Simonsen, Amphora laevissima var. perminuta Grunow, and Amphora laevis var. minuta Cleve.
2025, Our Nature
The present paper deals with 10 taxa belonging to 5 genera of Bacillariophycean algae first time from Maipokhari Lake of Ilam district. Out of these, 8 taxa viz., Eunotia diodon Ehr., E. gracilis (Ehr.) Rabenh., E. monodon Ehr. var.... more
The present paper deals with 10 taxa belonging to 5 genera of Bacillariophycean algae first time from Maipokhari Lake of Ilam district. Out of these, 8 taxa viz., Eunotia diodon Ehr., E. gracilis (Ehr.) Rabenh., E. monodon Ehr. var. bidens (Greg.) Sm., E. monodon Ehr. var. tropica Hust., Navicula placenta Ehr., Pinnularia conica Gandhi, P. sundaensis Hust. and Hantzschia amphioxys (Ehr.) Grun. var. capitata Muell. are being reported for the first time from Nepal. Key words: Algae, Bacillariophyceae, Diatom, Ilam, Maipokhari Lake, Nepaldoi:10.3126/on.v3i1.331Our Nature (2005) 3: 26-30
2025, CER (University of Belgrade, Institute of Chemistry, Technology and Metallurgy)
2025
In this work, the assessment of the ecological status of the Oum Er-rabie River basin was carried out by determining the physical-chemical, bacteriological and biological parameters. sampling Benthic macroinvertebrates and water were... more
In this work, the assessment of the ecological status of the Oum Er-rabie River basin was carried out by determining the physical-chemical, bacteriological and biological parameters. sampling Benthic macroinvertebrates and water were collected only once during the fourth seasons at the 31 stations upstream to downstream of the streams from spring 2018 to winter 2019. Physical-chemical quality was assessed from the Weighted Index (IP) based on 16 parameters (temperature, conductivity, dissolved oxygen, nitrate, nitrites, Ammonium, biochemical oxygen demand, chemical oxygen demand, turbidity, ortho phosphate, calcium, magnesium, chloride, sulphate) and revealed an average to very poor quality in most stations. The microbiological quality, based on the assessment of the three parameters: fecal coliforms, total coliforms and fecal streptococcus, varies between, good and bad. The values of the biotic indices, Iberian Biological Monitoring Working Group Index (IBMWP), River Habitat Index (IHF) and River Quality Index (QBR), classify the waters of the various prospected stations as good quality waters for upstream stations (S2, S10, S12, S14, S15, S16) and in the medium to very bad quality category for other localities except for two stations (S27, S30) which are downstream but have good qualities.
2025, Phycological Research
We used light and scanning electron microscope analyses to quantify morphometric features (valve length, width, stria density, lineola density and valve curvature) from the observation of valves representing Seminavis pusilla. Cluster... more
We used light and scanning electron microscope analyses to quantify morphometric features (valve length, width, stria density, lineola density and valve curvature) from the observation of valves representing Seminavis pusilla. Cluster analysis based on Gaussian mixture models and the expectation-maximization algorithm was used for delineating two species, Seminavis pusilla sensu stricto and Seminavis lata (Krammer) Rioual comb. et stat. nov. By comparison with S. pusilla, S. lata is characterized by wider valves and lower stria density. The two species have also markedly different ecology. S. pusilla is most abundant in the most saline lakes of the dataset, while S. lata is most abundant in the less saline lakes. Our results indicate that combining the two species into S. pusilla sensu lato would lead to a loss of ecological information and a decrease of the performance of transfer functions developed for quantitative reconstruction of past salinity from fossil diatom assemblages in sediment cores.
2025, Authorea
Diatoms (Bacillariophyceae) are widely used as bioindicators of present and past water quality because they inhabit the vast majority of aquatic ecosystems, are very diverse, highly sensitive to a variety of environmental conditions, and... more
Diatoms (Bacillariophyceae) are widely used as bioindicators of present and past water quality because they inhabit the vast majority of aquatic ecosystems, are very diverse, highly sensitive to a variety of environmental conditions, and are characterized by silicified cell walls that favor their long-term preservation in sediments. Alongside with traditional morphological analyses, metabarcoding has become a valuable tool to study the community structures of various organisms, including diatoms. Here, we aimed to test whether the quantity of sediment sample used for DNA extraction is affecting the results obtained from high-throughput sequencing (metabarcoding) of the diatom rbcL region by isolating DNA from 10 g and 0.5 g (wet weight) of lake surface sediment samples. Because bioinformatics processing of metabarcoding data may affect the outcome, we also tested the consistency of the results from three different pipelines. Additionally, the agreement between metabarcoding data and morphological inventories of corresponding samples were compared. Our results demonstrate highly uniform patterns between the diatom rbcL amplicons from 10 g and 0.5 g of DNA extracts (HTS 10 and HTS 0.5, respectively). Furthermore, metabarcoding results were highly consistent among the data sets produced by different bioinformatics pipelines. Comparing results from metabarcoding and microscopy, we identified some taxonomic mismatches, which are related to the common issue of incompleteness of the sequence databases, but also to inconsistencies in diatom taxonomy in general and potential dissolution effects of diatom valves caused by high alkalinity of the investigated lake waters. Nevertheless, multivariate community analysis demonstrated highly similar results between data sets identified by microscopy and metabarcoding, further confirming that metabarcoding is a viable alternative for identifying diatom-environment relationships.
2025, Journal of Environmental Biology
Taxonomic analysis of fresh water phytoplankton based on bright field microscopy and SEM studies is yet to be done in depth that may elucidate a number of new taxa. The present study on the assemblage of fresh water phytoplankton is... more
Taxonomic analysis of fresh water phytoplankton based on bright field microscopy and SEM studies is yet to be done in depth that may elucidate a number of new taxa. The present study on the assemblage of fresh water phytoplankton is focused to interpret the ecological condition of the studied water body of Bankura District in West Bengal. hytoplankton samples were collected from water bodies of Bankura District, West Bengal during the winter season. Planktonic algal taxa were analyzed using Scanning Electron Microscopy after preliminary observations made under Bright Field Microscopy. Qualitative and quantitative analyses of the phytoplankton were done for accurate taxonomic assignment of the taxa and interpretation of ecological perspectives. The qualitative analysis revealed an assemblage of phytoplankton that includes ten taxa. In the present assemblage, euglenophytes are represented by only one species, whereas, five species of desmids belonging to three genera and four species of diatoms belonging to four genera have been identified and illustrated. Quantitatively amongst the different groups of phytoplankton, desmids are dominant (57%) followed by diatoms (40%) with a minor representation of euglenophytes (3%). The qualitative and quantitative analyses of the phytoplankton assemblage indicate an oligotrophic condition.
2025, European Journal of Taxonomy
A new benthic freshwater diatom, Fragilaria rinoi Almeida & C.Delgado sp. nov., is described from river periphyton samples in Portugal. Fragilaria rinoi sp. nov. is illustrated and discussed based on populations collected from the Vouga,... more
A new benthic freshwater diatom, Fragilaria rinoi Almeida & C.Delgado sp. nov., is described from river periphyton samples in Portugal. Fragilaria rinoi sp. nov. is illustrated and discussed based on populations collected from the Vouga, Mondego and Lis river basins in central Portugal and compared with the type material of Fragilaria vaucheriae (Kütz.) J.B.Petersen. The morphological features of the new diatom species are documented through light and scanning electron micrographs, including a comparative analysis with related species of the genus (F. candidagilae Almeida, C.Delgado, Novais & S.Blanco, F. intermedia Grunow in Van Heurck, F. neointermedia Tuji & D.M.Williams, F. recapitellata Lange-Bert. & Metzeltin, F. perminuta (Grunow) Lange-Bert., F. vaucheriae and F. microvaucheriae C.E.Wetzel & Ector). Fragilaria rinoi sp. nov. is characterized by solitary cells without spines, lanceolate valves with slightly rostrate apices, a narrow, linear axial area, and a large, unilateral...
2025, HAL (Le Centre pour la Communication Scientifique Directe)
Coscinodiscus dispar Héribaud described by Héribaud in 1893 has been reported from Miocène, Pliocène sites of France. A detailed light and scanning électron microscope study was undertaken to détermine a description of the species.... more
Coscinodiscus dispar Héribaud described by Héribaud in 1893 has been reported from Miocène, Pliocène sites of France. A detailed light and scanning électron microscope study was undertaken to détermine a description of the species. Coscinodiscus dispar Héribaud does not fit in any of the known fossil gênera and this is discussed. RÉSUMÉ -Coscinodiscus dispar Héribaud, décrit par F. Héribaud en 1893, a été trouvé dans le Miocène et le Pliocène de France. Une étude détaillée en microscopie optique et en microscopie électronique à balayage a mis en évidence les caractères ultrastructuraux de l'espèce. Une discussion basée sur les caractères ultrastructuraux de Coscinodiscus dispar Héribaud montre pourquoi cette espèce n'appartient pas aux genres fossiles connus.
2024
Diatoms are commonly used in environmental assessments to detect pollution and eutrophication. The specific pollution sensitivity index (SPI) is one of the most frequently used indices, which assigns scores to diatom taxa based on their... more
Diatoms are commonly used in environmental assessments to detect pollution and eutrophication. The specific pollution sensitivity index (SPI) is one of the most frequently used indices, which assigns scores to diatom taxa based on their sensitivity to pollution. The study analyzed diatom communities in the Duero River basin in Spain to examine the relationship between SPI scores and various limnological variables. A GLM model showed that phosphates, nitrites, and water temperature were the main factors explaining SPI variability. The study also reviews previous results using SPI for water quality monitoring in different world regions, highlighting the role of nutrients in general as major drivers of SPI values worldwide. Overall, the findings reinforce the reliability of SPI as a metric for biological monitoring in various watercourses.
2024
The objective of this study was to explore the environmental factors having the greatest influence on the distribution and abundance of epipelic diatom species in different wetlands in southern Spain. We previously defined four groups of... more
The objective of this study was to explore the environmental factors having the greatest influence on the distribution and abundance of epipelic diatom species in different wetlands in southern Spain. We previously defined four groups of conductivity categories: fresh (< 0.8 mS cm−1), oligosaline (< 8 mS cm−1), mesosaline (8–30 mS cm−1) and eusaline (> 30 mS cm−1). A dbRDA analysis performed on a subset of 36 of the 53 wetlands, using a total of 25 environmental variables, showed that five environmental variables (conductivity, pH, wetland area, silicates, and total suspended solids) were the best explanatory variables for the diatom assemblage, with conductivity being the main explanatory variable. Nonmetric multidimensional scaling (nMDS) analysis performed on the set of 53 wetlands revealed significant differences in diatom composition among the four conductivity groups. The key species in the eusaline group were Tryblionella pararostrata, Halamphora sp.1 and Cocconeis euglypta, whereas in the mesosaline and oligosaline group, these were Navicula veneta, Tryblionella hungarica and Nitzschia inconspicua. Finally, in the fresh group dominated Achnanthidium minutissimum, Navicula veneta and Gomphonema exilissimum. This study on epipelic diatoms can therefore contribute to the knowledge of these organisms in a European region with a high diversity of wetland typologies.
2024
The initial valves of two Cymbella species are observed under a scanning electron microscope, and the perizonium ultrastructure of Cymbella is revealed for the first time. The perizonium is composed of alternate nodes and internodes and... more
The initial valves of two Cymbella species are observed under a scanning electron microscope, and the perizonium ultrastructure of Cymbella is revealed for the first time. The perizonium is composed of alternate nodes and internodes and lacks transverse perizonium bands. Four new species, Cymbella apiculatophora sp. nov., C. hunanensis sp. nov., C. juglandis sp. nov. and C. menyuanensis sp. nov., are described using light and scanning electron microscopy based on epilithon samples collected from rivers in Hunan and Qinghai Provinces, China. Cymbella menyuanensis is a typical Cymbella species that closely resembles species in the group around C. cymbiformis Agardh, the type species of the genus. Cymbella apiculatophora is similar to C. sinensis Metzeltin & Krammer, while Cymbella hunanensis is closer to the C. hustedtii Krasske group. The last species, C. juglandis, has a cymbelloid valve outline, an obscured intermissio, internal occlusions of the areolae, dorsally deflected distal raphe fissures and a divided apical pore field at each apex, and it does not appear to belong to any group. In addition, new observations on C. cf. excisiformis Krammer and C. hustedtii are reported. The current concept of the genus Cymbella does not represent a monophyletic group as shown by molecular phylogenetic analyses. However, these analyses are still at the preliminary stage and are not yet sufficient to support a complete revision of the genus. Thus, although extremely diverse ultrastructural features are observed in the six Cymbella species investigated in this paper, we prefer to keep them within Cymbella at this moment for the sake of nomenclatural stability.
2024
Aim Understanding the roles of deterministic and stochastic processes in community assembly is essential for gaining insights into the biogeographical patterns of biodiversity. However, the way community assembly processes operate is... more
Aim Understanding the roles of deterministic and stochastic processes in community assembly is essential for gaining insights into the biogeographical patterns of biodiversity. However, the way community assembly processes operate is still not fully understood, especially in oceanic islands. In this study, we examine the importance of assembly processes in shaping diatom communities in islands and continents, while also investigating the influence of climate and local water chemistry variables on species distributions. Location Global. Taxon Stream benthic diatoms. Methods We used diatom datasets from five continents and 19 islands and applied beta diversity analyses with a null model approach and hierarchical joint species distribution modelling. To facilitate comparisons with continents, we used continental area equivalents (CAEs), which represent continental subsets with comparable areas and the same number of study sites as their corresponding islands counterparts. Results We found that homogeneous selection (i.e., communities being more similar than the random expectation) was the dominant assembly process within islands whereas stochastic processes tended to be more important within continents. In addition, assembly processes were influenced by study scale and island isolation. Climatic variables showed a greater influence on species distribution than local factors. However, in islands, local environmental variables had a greater impact on the distributions of unique taxa as opposed to non-unique taxa. Main Conclusions We observed that the assembly processes of diatom communities were complex and influenced by a combination of deterministic and stochastic forces, which varied across spatial scales. In islands, there was no universal pattern of assembly processes, given that their influence depends on abiotic conditions such as area, isolation, and environmental heterogeneity. In addition, the sensitivity of species occurring uniquely in islands to local environmental variables suggests that they are perhaps less vulnerable to climatic changes but may be more influenced by changes in local physicochemistry.
2024
Interspecific abundance-occupancy relationships (AOR) have been addressed as one of the most important questions regarding the spatial ecology of diatoms. Whereas positive interspecific AOR is a common feature of ecological communi- ties,... more
Interspecific abundance-occupancy relationships (AOR) have been addressed as one of the most important questions regarding the spatial ecology of diatoms. Whereas positive interspecific AOR is a common feature of ecological communi- ties, little is known about its causes and consequences. Studies to date confirm that AOR depends mostly on the ecological features exhibited by the species pool ana- lyzed, particularly niche characteristics and habitat guilds. The present study aims to test the persistence of such patterns using pond diatoms at a mesoscale level. Epiphytic and planktonic diatoms were collected in 29 shallow ponds throughout the Northern Iberian Plateau. Analysis of covariance (ANCOVA) tests revealed contrasting patterns when both assemblages are compared; for a given abundance level, epiphytic species were present in twice as many locations as planktonic ones, with noticeable effects also attributable to cell biovolume and motile guild. Contrary to our expectations, niche characteristics, measured in terms of species sensitivity and indicator value with respect to abiotic variables, had a negligible effect on AOR models. The consequences of such results are briefly discussed at a theoretical level.
2024
This research presents a significant contribution to the methodologies and protocols for studying diatom communities in cryoconite holes on glaciers. Cryoconite holes are unique microenvironments found on glacial surfaces that support... more
This research presents a significant contribution to the methodologies and protocols for studying diatom communities in cryoconite holes on glaciers. Cryoconite holes are unique microenvironments found on glacial surfaces that support intricate microbial ecosystems, with diatoms playing a pivotal role in these communities. The refined methodologies developed in this study include optimizing sampling techniques to ensure that collections are both representative and diverse, which is crucial for accurate ecological assessments. Additionally, advanced digestion processes have been implemented to effectively isolate and purify diatom samples while minimizing contaminants, thereby improving sample integrity. Improved microscopic mounting techniques enhance visual clarity, facilitating more precise identifications of diatoms under the microscope. Furthermore, integrating DNA-based taxonomy broadens the taxonomic scope, providing valuable molecular insights into the diversity and evolutionary relationships of diatoms. Collectively, these protocols aim to enhance the reliability, depth, and multidimensional understanding of diatom ecology in cryoconite holes and broader glacial ecosystems, ultimately contributing to the field of glaciology and microbial ecology.
2024, HAL (Le Centre pour la Communication Scientifique Directe)
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Flore diatomique des bassins versants de l'Agnéby et de la Mé (Côte d'Ivoire)
2024
Relative % (±SE) frequency of diatoms and collection dates for selected streams in the Lahontan Basin …………………………………………i APPENDIX TABLE 1b. Relative % (±SE) frequency of diatoms and collection dates for selected streams in the Lahontan... more
Relative % (±SE) frequency of diatoms and collection dates for selected streams in the Lahontan Basin …………………………………………i APPENDIX TABLE 1b. Relative % (±SE) frequency of diatoms and collection dates for selected streams in the Lahontan Basin …………………………………………x APPENDIX TABLE 1c: Relative % (±SE) frequency of diatoms and collection dates for selected streams in the Lahontan Basin ………………………………………xix APPENDIX TABLE 1d: Relative % (±SE) frequency of diatoms and collection dates for selected streams in the Lahontan Basin ……………………………………xxviii APPENDIX TABLE 1e: Relative % (±SE) frequency of diatoms and collection dates for selected streams in the Lahontan Basin ……………………………………..xxvii APPENDIX TABLE 1f: Relative % (±SE) frequency of diatoms and collection dates for selected streams in the Lahontan Basin ………………………………………xlvi APPENDIX TABLE 1g: Relative % (±SE) frequency of diatoms and collection dates for selected streams in the Lahontan Basin ………………………………………..lv APPENDIX TABLE 1h: Relative % (±SE) frequency of diatoms and collection dates for selected streams in the Lahontan Basin ………………………………………lxiv APPENDIX TABLE 1i: Relative % (±SE) frequency of diatoms and collection dates for selected streams in the Lahontan Basin ……………………………………. lxxiii APPENDIX TABLE 1j: Relative % (±SE) frequency of diatoms and collection dates for selected streams in the Lahontan Basin …………………………………….lxxxii APPENDIX TABLE 1k: Relative % (±SE) frequency of diatoms and collection dates for selected streams in the Lahontan Basin ……………………………………….xci APPENDIX TABLE 1l: Relative % (±SE) frequency of diatoms and collection dates for selected streams in the Lahontan Basin …………………………………………c APPENDIX TABLE 1m: Relative % (±SE) frequency of diatoms and collection dates for selected streams in the Lahontan Basin ……………………………………….cix
2024, Acta Botanica Croatica
Most studies that consider the relationship of diatoms and water quality have focused their attention on the questions and practicalities of water pollution or perturbations in some form or another. Many models and studies have... more
Most studies that consider the relationship of diatoms and water quality have focused their attention on the questions and practicalities of water pollution or perturbations in some form or another. Many models and studies have demonstrated the environmental tolerances or changes in structure of diatom communities related to environmental challenges. This focus on the impacted end of the water quality spectrum has led, of necessity, to issues ultimately related to habitat restoration. We contend that a concentrated effort to develop more fully the theory and there is a need for practice related to oligotrophy, the other, ignored end of the water quality spectrum. We explore the historical usages of the term oligotrophy, as well as the challenges and promise of autecological and community approaches to understanding oligotrophy, and the possibility of focusing more on conservation rather than restoration in water quality issues.
2024, DergiPark (Istanbul University)
This study was carried out in 17 high mountain lakes and a pond in the Artabel Lakes Nature Park (Gümüşhane) on August 15, 2013 and August 13, 2016. In the present study, epipelic, epilitic and epiphytic algal flora of lakes were... more
This study was carried out in 17 high mountain lakes and a pond in the Artabel Lakes Nature Park (Gümüşhane) on August 15, 2013 and August 13, 2016. In the present study, epipelic, epilitic and epiphytic algal flora of lakes were determined and a total of 95 taxa were recorded belonging to Bacillariophyta division. 9 of the taxa belonging to Bacillariophyta were determined to be new records for the freshwater diatom flora of Turkey. These taxa were identified as Aulacoseira lacustris (Grunow) Krammer f. tenuior Houk, Klee and Passauer, Orthoseira roeseana (Rabenhorst) Pfitzer, Cyclotella ambigua Grunow, Planothidium distinctum (Messikommer) Lange-Bertalot, Psammothidium helveticum (Hustedt) Bukhtiyarova and Round, Diploneis petersenii Hustedt, Frustulia crassinervia (Brébisson ex
2024, Turkish Journal of Fisheries and Aquatic Sciences
The main goal of this study is to determine the composition, diversity and ecology of benthic diatoms in Karagöl Lake in Karagöl-Sahara National Park. Monthly sampling (from sediments, stones and aquatic plants in littoral zone of the... more
The main goal of this study is to determine the composition, diversity and ecology of benthic diatoms in Karagöl Lake in Karagöl-Sahara National Park. Monthly sampling (from sediments, stones and aquatic plants in littoral zone of the lake) taken in three consecutive years revealed 57 diatom taxa with Gomphonema and Pinnularia being the most abundant species while other genera are represented with three or fewer species. Lindavia ocellata was the most dominant taxon in the samplings examined throughout the whole study. The values of diversity and evenness indices are high during the spring and early summer. Based on cluster analysis for monthly samples of epipelic diatom, there are two different groups at the lowest similarity level. The associations between August 2010 and September 2010 months are the most significant with 86.02%. The organism number of epipelic diatoms showed positive correlation (P<0.01) with dissolved oxygen, while negative correlation (P<0.05) with tempe...
2024, Plant Ecology and Evolution
Background and aims – Confusion over the taxonomic identity of Neidium iridis (Ehrenb.) Cleve (= Navicula iridis Ehrenb.) has persisted for more than 130 years with identifications of valve shapes varying from elliptical to linear and... more
Background and aims – Confusion over the taxonomic identity of Neidium iridis (Ehrenb.) Cleve (= Navicula iridis Ehrenb.) has persisted for more than 130 years with identifications of valve shapes varying from elliptical to linear and sizes from 100 to 300 µm. This confusion can be linked to the rarity of the species and poor attention to the original line drawings of Ehrenberg. This study examines the type material of Navicula iridis and further uses additional material from North America to define the species Neidium iridis. Methods – Mica and material from Christian Gottfried Ehrenberg’s Collection were studied to examine Navicula iridis. Light and electron microscope techniques were used to document the variability of valve morphology of original material in comparison with other fossil and recent materials. Key results – Ehrenberg designated no nomenclatural type for Navicula iridis at the place of its first description, and until recently the original material was not studied....
2024
The first record of the genus Pliocaenicus from middle Miocene deposits is presented in this paper. This record from Changbai (Jilin Province, China) places the origin of the genus further back into the middle Miocene. The genus has been... more
The first record of the genus Pliocaenicus from middle Miocene deposits is presented in this paper. This record from Changbai (Jilin Province, China) places the origin of the genus further back into the middle Miocene. The genus has been so far reported from the late Miocene/early Pliocene till Recent. The population from Changbai belongs to the group of Pliocaenicus species possessing complex alveolae, such as P. cathayanus Wang, P. jilinensis Wang and P. omarensis (Kuptsova) Stachura-S. et Khursevich. Both P. cathayanus and P. jilinensis have been described from China (Pliocene deposits), and are only known from the type locality. The third species, P. omarensis is reported from Eurasia and Africa (age range: late Miocene-Pleistocene). In this report we describe P. changbaiense, a new species from China, and focus on those characters having the potential for developing further an evolutionary and taxonomical concept in Pliocaenicus. We anticipate that these will contribute to our understanding of the driving forces of diatom dispersal.
2024, Anales Del Jardin Botanico De Madrid
Resumen. Se describe la diatomea Encyonema nevadense S.Blanco & al. sp. nov. como especie nueva, a partir de muestras de epiliton recogidas en una laguna de alta montaña del Parque Nacional de Sierra Nevada. Este taxon se caracteriza por... more
Resumen. Se describe la diatomea Encyonema nevadense S.Blanco & al. sp. nov. como especie nueva, a partir de muestras de epiliton recogidas en una laguna de alta montaña del Parque Nacional de Sierra Nevada. Este taxon se caracteriza por la presencia de valvas lanceoladas estrechas con una moderada dorsiventralidad, y la presencia de areolas con aperturas externas irregulares. Se compara la población tipo con la de Encyonema perpusillum (A.Cleve) D.G.Mann y sus variedades, la especie morfológicamente más cercana dentro del género. Se discuten brevemente las impliaciones ecológicas y biogeográficas del descubrimiento.
2024, Iheringia Serie Botanica
The present study aimed to describe the fl oristic composition and the changes of diatom associations in the Itajai-Mirim River along its altitudinal gradient and with different land uses. The study was based on quarterly sampling of... more
The present study aimed to describe the fl oristic composition and the changes of diatom associations in the Itajai-Mirim River along its altitudinal gradient and with different land uses. The study was based on quarterly sampling of epilithon at six stations between 2004 and 2006. A total of 79 taxa, distributed in 24 families and 36 genera, were identifi ed. The families with the highest species richness were Naviculaceae, Gomphonemataceae, Cymbellaceae, and Bacillariaceae. These families along with the Achnanthidiaceae had the greatest relative abundances. Changes in diatom associations along the altitudinal gradient of the Itajai-Mirim River were more evident in lowland areas, with anthropogenic activities such as sand extraction and discharge of domestic and industrial effl uents. The important species, as provided by the Important Species Index, refl ected the environmental conditions.
2024, Science of the Total Environment
To unveil possible changes in diatom communities in Cypriot streams over the last ten years or so, we selected samples from the years 2020, 2021, and 2022 for the “recent” dataset (N = 119) and samples from the years 2010 and 2011 for the... more
To unveil possible changes in diatom communities in Cypriot streams over the last ten years or so, we selected samples from the years 2020, 2021, and 2022 for the “recent” dataset (N = 119) and samples from the years 2010 and 2011 for the “historical” dataset (N = 108). Biotic homogenization has become a truly global phenomenon. Here we show that, over the last ten years, in response to increased water temperature, conductivity, and discharge variability due to climate-change, Cypriot stream diatom communities include a higher number of trivial (= widespread, tolerant, and opportunistic), aerial, and thermophilic species, have reduced β-diversity and increased nestedness. Moreover, IndVal analysis shows that indicator species from the historical dataset were
characteristic, often relatively rare species, while the indicators of the recent dataset were a group of typical trivial, eutraphentic, and thermophilic species. As is almost always the case, the diatom communities we studied were subjected to multiple stressors, often affecting them in opposite ways. Besides the increase in trivial species,
the reduction in β-diversity, and the rise in nestedness mentioned above, the diatom assemblages we studied also showed an increase in α-diversity that could be due to a moderate reduction in nutrients in several sites. High ecological-integrity ecosystems, such as springs, waterfalls, and dripping rock-walls, in particular springs that were shown to be excellent hydrologic refugia in climates heavily affected by climate change, and the stream sites close to them should be carefully protected, as they can be refugia for sensitive and characteristic species that can recolonize the adjacent streams after adverse climatic events.
2024, Journal of entomology and zoology studies
Aquatic macroinvertebrates and diatoms are widely used to study the water quality of rivers. This study was carried out on the Actopan River, in the localities of Santa Rosa and La Linda, Ver. In Santa Rosa, the family most abundant was... more
Aquatic macroinvertebrates and diatoms are widely used to study the water quality of rivers. This study was carried out on the Actopan River, in the localities of Santa Rosa and La Linda, Ver. In Santa Rosa, the family most abundant was Hydraenidae with 46 organisms. The BMWP index, it reached 80. In the locality La Linda, the gastropod of family Bithyniidae with 896 organisms. The BMWP index it reached 68. With respect to diatoms, at locality of Santa Rosa, the genera most abundant was Diatoma sp. with 68 organisms. In the locality of La Linda, the most abundant was Fragilaria with 11 organisms. By applying the PDI similar values were reached, 1.53 for Santa Rosa and 1.56 for La Linda. It is convenient to continue with macroinvertebrates and benthonic diatom study in the zone of Actopan river, because it allows to determine how the water quality fluctuates through time.
2024, Programme and Abstracts - 13th European Diatom Meeting
2024, Phytotaxa
A cross-check of botanical names databases revealed the presence of 19 cases of homonymy which are hereby resolved by proposing replacement names. Most cases concern diatom genera (Bacillariophyta) names which are preoccupied by... more
A cross-check of botanical names databases revealed the presence of 19 cases of homonymy which are hereby resolved by proposing replacement names. Most cases concern diatom genera (Bacillariophyta) names which are preoccupied by spermatophytes. While Loranthella nom. nov. (Spermatophyta, Loranthaceae) and Ochradiscus nom. nov. (Spermatophyta, Resedaceae) are proposed as new names for spermatophytes, new diatom names are proposed for genera that are currently placed in the families Amphipleuraceae, Coscinodiscaceae, Hemiaulaceae, Hemidiscaceae, Melosiraceae, Metascolioneidaceae nom. nov., Naviculaceae, Pyxillaceae, Stictodiscaceae and Surirellaceae. With one exception (i.e. Eileencoxia nom. nov.) all remaining diatom genera that are discussed in the present paper are marine and/or fossil elements. The particularities of each case are briefly discussed. A total of one hundred and three new combinations are proposed.
2024, Bulletin of Pure and Applied Sciences
In recent years, diatom studies have been consisting of different approach i.e., taxonomic study, contamination history, paleoclimate etc. The significant study has been reported from the different part of the Indian Especially in India,... more
In recent years, diatom studies have been consisting of different approach i.e., taxonomic study, contamination history, paleoclimate etc. The significant study has been reported from the different part of the Indian Especially in India, from the last several decades the study on diatom shifted from taxonomical classification to palaeothermometry study using isotopic analysis. To know the present status and get the future direction it is very important to review the past studies which not only gives the ample information about the records available but also benefitting to get future direction. In the present review we present the comprehensive review on records available from three different geopolitical regions. The review on these three regions shows that most of the work Indian parts in past decades diatom is mostly used for taxonomical and pollution study. diatom diversity has not been examined in many Indian regions. direction towards palaeothermometry reconstruction using advance analytical techniques such as stable isotope and others.
2024
Didymosphenia geminata (Lyngbye) M. Schmidt es una diatomea de agua dulce, originaria del hemisferio norte, que genera proliferaciones mucilaginosas en aguas oligotróficas. D. geminata se ha expandido rápidamente con éxito fuera de su... more
Didymosphenia geminata (Lyngbye) M. Schmidt es una diatomea de agua dulce, originaria del hemisferio norte, que genera proliferaciones mucilaginosas en aguas oligotróficas. D. geminata se ha expandido rápidamente con éxito fuera de su rango de distribución nativo en la última década, invadiendo ríos y lagos de Nueva Zelanda, Argentina y Chile. En el caso de Argentina todas las cuencas invadidas son de gran importancia recreativa, y en la mayoría de los casos pertenecen a Áreas Protegidas. La primera cuenca invadida en Argentina fue la del río Futaleufú. El objetivo de este estudio fue analizar la composición de la comunidad durante el período comprendido entre el mes de julio 2010 y noviembre de 2013 y evaluar
2024, Frontiers in Ecology and Evolution
Introduction: Non-perennial rivers and streams are increasingly present, in part because of climate change, even in the temperate climate. However, how the loss of connectivity and complete drying affect microphytobenthos in general and... more
Introduction: Non-perennial rivers and streams are increasingly present, in part because of climate change, even in the temperate climate. However, how the loss of connectivity and complete drying affect microphytobenthos in general and diatom communities in particular has gone mostly unstudied. Methods: With this paper, we aim to close this gap, identifying diatom biodiversity through manual digital microscopy and rbcL amplicon sequencing, to observe a) which method is better suited to it and b) how the ecotone flowpool-dry affects diatom diversity under duress. Three karstic, non-perennial rivers and streams with a gradient from natural to anthropogenically disturbed were sampled under flooding conditions and after a long and intense drought in 2022. Results: Our results show that digital microscopy shows a higher diversity and species richness than amplicon sequencing. We posit that this might be due to a reduced pool of subaerophile taxa having been sequenced and being part of the reference database. Furthermore, the effect of drying only resulted in a reduction in diversity after this drought, although the biofilm was still alive under these conditions. Discussion: To use amplicon sequencing for non-perennial river diatom diversity monitoring, the reference databases will have to be adapted to such systems, as most rivers may be subjected to drying regularly in the future.
2024, MDPI Water
This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
2024
Diatom Lab Microscope Test Slide in commemoration of Edmund J. Spitta
2024, Anoptral phase contrast applied to diatoms
Anoptral phase contrast applied to diatoms: a study by
means of test diatoms on the advantages originally described by its
discoverer Alvar Wilska, over the standard (positive) phase contrast.
2024, Mediterranean Marine Science
Populations of the fragilarioid diatom Synedropsis roundii are described from the phytoplankton of the Albufera of Valencia, a large and shallow eutrophic lagoon in the Spanish Mediterranean coast. The specimens collected are described... more
Populations of the fragilarioid diatom Synedropsis roundii are described from the phytoplankton of the Albufera of Valencia, a large and shallow eutrophic lagoon in the Spanish Mediterranean coast. The specimens collected are described and illustrated with light and scanning electron microscopy. This is the first documented record of this species since its description, and the first illustrated record of the genus in the Mediterranean region. The Albufera lagoon and the type locality of the species (Imboassica Lagoon, SE Brazil) are similar in some ecological features. The ecological and biogeographical implications of this finding are briefly discussed.
2024
O presente trabalho forma parte de um estudo sobre as diatomáceas do perifiton da bacia alta do Rio Sauce Grande, águas acima da Represa Paso de las Piedras, como base para a utilização destes organismos como indicadores de qualidade da... more
O presente trabalho forma parte de um estudo sobre as diatomáceas do perifiton da bacia alta do Rio Sauce Grande, águas acima da Represa Paso de las Piedras, como base para a utilização destes organismos como indicadores de qualidade da água. As amostras foram coletadas no período de agosto- setembro de 2000 em 14 estações localizadas sobre o leito principal e afluentes. Como resultado da análise em microscópio óptico e eletrônico de varredura, foram identificados 92 táxons infragenéricos dos quais Achnanthes cf. minutissima var. inconspicua, Navicula cryptotenelloides, N. microcari y N. reichardtiana são mencionados pela primeira vez na Argentina. Craticula halophila, Cyclotella pseudostelligera, Denticula valida, Diatoma vulgare, Fistulifera saprophila, Fragilaria aff. elliptica, Hippodonta capitata, Luticola mutica, Navicula capitatoradiata, N. tripunctata, Nitzschia amphibia, N. capitellata, N. cf. communis, N. fonticola, N. cf. gandersheimiensis f. tenuirostris, N. heufleriana,...