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Bart Van De Vijver - One of the best experts on this subject based on the ideXlab platform.
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Pinnularia schoelynckiana, a new limnoterrestrial diatom species (Bacillariophyta) from the sub-Antarctic Iles Kerguelen (southern Indian Ocean)
Botany Letters, 2020Co-Authors: Bart Van De Vijver, Pieter Scholberg, Marc LebouvierAbstract:An unknown Pinnularia taxon was recorded during a survey of the limno-terrestrial diatom flora of some hot springs in the Val Travers area (Grande Terre, Iles Kerguelen, sub-Antarctic region). The morphology of the species was investigated using both light and scanning electron microscopy. Based on these results, the species could not be identified using the currently available literature and is therefore described as a new species Pinnularia schoelynckiana sp. nov. The new species is characterized by rhombic-lanceolate valves, radiate, geniculate striae changing into strongly convergent near the apices and an undulating, lateral raphe. A detailed morphological comparison is made with similar Pinnularia species, described from the Antarctic Region and worldwide. Brief notes on the associated diatom flora and its ecology are added.
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Temporal Evolution of Diatoms in a Temporary Pond Situated in the Massif du Sancy Mountains (Massif Central, France) and Description of a New Pinnularia Species
Diversity, 2020Co-Authors: Aude Beauger, Luc Ector, Elisabeth Allain, Olivier Voldoire, Carlos Wetzel, Bart Van De VijverAbstract:A floristic survey was performed on a temporary pond, "Laqui du Seignavoux", situated in the Mont-Dore massif of the French Massif Central, between 2017 and 2019. Except in 2017, each year, we performed four sampling campaigns from April/May to December. Water samples and diatoms were collected. The temporary pond evolved from a poorly mineralized ecosystem due to snow, inducing oligotrophic and oligosaprobic water, well oxygenated in spring, to a more mineralized, less oxygenated, eutrophic-hypereutrophic, and polysaprobic environment in summer. This change in abiotic conditions was found to be linked to the presence of cattle, beginning in May, that trample and excrete in the pond, leading to higher ammonium and nitrate concentrations. During this period, the dominant species were Pinnularia sp., Nitzschia palea, and Nitzschia palea var. tenuirostris. In spring and winter, different species of Eunotia dominated the community such as Eunotia pseudogroenlandica. Finally, light microscopy (LM) and scanning electron microscopy (SEM) observations on a new species of the genus Pinnularia from the temporary pond are presented and the ecological preferences are discussed.
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Pinnularia schoelynckiana, a new limnoterrestrial diatom species (Bacillariophyta) from the sub-Antarctic Iles Kerguelen (southern Indian Ocean)
Botany Letters, 2019Co-Authors: Bart Van De Vijver, Pieter Scholberg, Marc LebouvierAbstract:An unknown Pinnularia taxon was recorded during a survey of the limno-terrestrial diatom flora of some hot springs in the Val Travers area (Grande Terre, Iles Kerguelen, sub-Antarctic region). The ...
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Pinnularia subcatenaborealis sp. nov. (Bacillariophyta) a new chain-forming diatom species from King George Island (Maritime Antarctica)
Phytotaxa, 2018Co-Authors: Natalia Kochman-kędziora, Eveline Pinseel, Mateusz Rybak, Teresa Noga, Maria Olech, Bart Van De VijverAbstract:During a survey conducted on the freshwater diatom flora of small shallow pools on the Ecology Glacier forefield (King George Island, Maritime Antarctic Region), an unknown spine-bearing chain-forming Pinnularia species, belonging to the Pinnularia borealis species complex, was found. Although it closely resembles the recently described Pinnularia catenaborealis from James Ross Island and Vega Island (Antarctic Peninsula), a unique set of morphological characteristics revealed in both light and scanning electron microscopy clearly discriminates the specimens of King George Island as a new species. Pinnularia subcatenaborealis Kochman-Kedziora, Pinseel & Van de Vijver sp. nov. can be distinguished from P. catenaborealis by an overall smaller valve size, the presence of irregularly formed silica outgrowths on the mantle and small, irregular plates located near the apices. The new taxon is so far only recorded from a small pool with circumneutral pH and very low conductivity.
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Pinnularia catenaborealis sp. nov. (Bacillariophyceae), a unique chain-forming diatom species from James Ross Island and Vega Island (Maritime Antarctica)
Phycologia, 2017Co-Authors: Eveline Pinseel, Pieter Vanormelingen, Wim Vyverman, Kateřina Kopalova, Eva Hejduková, Bart Van De VijverAbstract:Abstract: A recent detailed survey of the Maritime Antarctic diatom flora using a fine-grained taxonomy resulted in the description of many new species of Pinnularia in general and the section Distantes, including the P. borealis species complex, in particular. Moreover, DNA-based studies of P. borealis revealed that many more species need to be described within this complex. During a survey of the freshwater littoral diatom flora of James Ross Island (Ulu Peninsula) and Vega Island in Maritime Antarctica, a previously unknown chain-forming species in the P. borealis species complex of section Distantes was cultured from three different localities. Molecular phylogenies based on the nuclear-encoded D1–D3 large-subunit ribosomal DNA and plastid rbcL genes revealed that all cultures belong to a distinct highly supported lineage within the P. borealis species complex. Pinnularia catenaborealis sp. nov. is characterised by the presence of small spines located on a raised, thin silica ridge that almost entirel...
Mateusz Rybak - One of the best experts on this subject based on the ideXlab platform.
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Pinnularia subcatenaborealis sp. nov. (Bacillariophyta) a new chain-forming diatom species from King George Island (Maritime Antarctica)
Phytotaxa, 2018Co-Authors: Natalia Kochman-kędziora, Eveline Pinseel, Mateusz Rybak, Teresa Noga, Maria Olech, Bart Van De VijverAbstract:During a survey conducted on the freshwater diatom flora of small shallow pools on the Ecology Glacier forefield (King George Island, Maritime Antarctic Region), an unknown spine-bearing chain-forming Pinnularia species, belonging to the Pinnularia borealis species complex, was found. Although it closely resembles the recently described Pinnularia catenaborealis from James Ross Island and Vega Island (Antarctic Peninsula), a unique set of morphological characteristics revealed in both light and scanning electron microscopy clearly discriminates the specimens of King George Island as a new species. Pinnularia subcatenaborealis Kochman-Kedziora, Pinseel & Van de Vijver sp. nov. can be distinguished from P. catenaborealis by an overall smaller valve size, the presence of irregularly formed silica outgrowths on the mantle and small, irregular plates located near the apices. The new taxon is so far only recorded from a small pool with circumneutral pH and very low conductivity.
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First record of Pinnularia subinterrupta Krammer & Schroeter in Poland – a rare species in Europe
Biodiversity Research and Conservation, 2017Co-Authors: Teresa Noga, Mateusz RybakAbstract:The first record of occurrence of Pinnularia subinterrupta Krammer & Schroeter in Poland with the species ecological and morphological characteristics (including scanning electron microscope details) are provided. The species was observed in the material collected from the Jamow and Tokarka streams, flowing from the areas of raised bog in the Orava Region of southern Poland. Pinnularia subinterrupta occurred in low abundance, among mosses, and always at low water pH (3.3-4.8), conductivity (28-63 mS cm⁻¹) and temperature (3.9-9.6°C).
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first record of Pinnularia subinterrupta krammer schroeter in poland a rare species in europe
Biodiversity: Research and Conservation, 2017Co-Authors: Teresa Noga, Mateusz RybakAbstract:The first record of occurrence of Pinnularia subinterrupta Krammer & Schroeter in Poland with the species ecological and morphological characteristics (including scanning electron microscope details) are provided. The species was observed in the material collected from the Jamow and Tokarka streams, flowing from the areas of raised bog in the Orava Region of southern Poland. Pinnularia subinterrupta occurred in low abundance, among mosses, and always at low water pH (3.3-4.8), conductivity (28-63 mS cm⁻¹) and temperature (3.9-9.6°C).
Teresa Noga - One of the best experts on this subject based on the ideXlab platform.
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Pinnularia subcatenaborealis sp. nov. (Bacillariophyta) a new chain-forming diatom species from King George Island (Maritime Antarctica)
Phytotaxa, 2018Co-Authors: Natalia Kochman-kędziora, Eveline Pinseel, Mateusz Rybak, Teresa Noga, Maria Olech, Bart Van De VijverAbstract:During a survey conducted on the freshwater diatom flora of small shallow pools on the Ecology Glacier forefield (King George Island, Maritime Antarctic Region), an unknown spine-bearing chain-forming Pinnularia species, belonging to the Pinnularia borealis species complex, was found. Although it closely resembles the recently described Pinnularia catenaborealis from James Ross Island and Vega Island (Antarctic Peninsula), a unique set of morphological characteristics revealed in both light and scanning electron microscopy clearly discriminates the specimens of King George Island as a new species. Pinnularia subcatenaborealis Kochman-Kedziora, Pinseel & Van de Vijver sp. nov. can be distinguished from P. catenaborealis by an overall smaller valve size, the presence of irregularly formed silica outgrowths on the mantle and small, irregular plates located near the apices. The new taxon is so far only recorded from a small pool with circumneutral pH and very low conductivity.
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First record of Pinnularia subinterrupta Krammer & Schroeter in Poland – a rare species in Europe
Biodiversity Research and Conservation, 2017Co-Authors: Teresa Noga, Mateusz RybakAbstract:The first record of occurrence of Pinnularia subinterrupta Krammer & Schroeter in Poland with the species ecological and morphological characteristics (including scanning electron microscope details) are provided. The species was observed in the material collected from the Jamow and Tokarka streams, flowing from the areas of raised bog in the Orava Region of southern Poland. Pinnularia subinterrupta occurred in low abundance, among mosses, and always at low water pH (3.3-4.8), conductivity (28-63 mS cm⁻¹) and temperature (3.9-9.6°C).
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first record of Pinnularia subinterrupta krammer schroeter in poland a rare species in europe
Biodiversity: Research and Conservation, 2017Co-Authors: Teresa Noga, Mateusz RybakAbstract:The first record of occurrence of Pinnularia subinterrupta Krammer & Schroeter in Poland with the species ecological and morphological characteristics (including scanning electron microscope details) are provided. The species was observed in the material collected from the Jamow and Tokarka streams, flowing from the areas of raised bog in the Orava Region of southern Poland. Pinnularia subinterrupta occurred in low abundance, among mosses, and always at low water pH (3.3-4.8), conductivity (28-63 mS cm⁻¹) and temperature (3.9-9.6°C).
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The Pinnularia genus in south-eastern Poland with consideration of rare and new taxa to Poland
Oceanological and Hydrobiological Studies, 2014Co-Authors: Teresa Noga, Łukasz Peszek, Jadwiga Stanek-tarkowska, Anita PajączekAbstract:In the studies conducted in 2007–2012 in south-eastern Poland, 56 diatom taxa were found from the Pinnularia genus. Pinnularia brebissonii (Kutzing) Rabenhorst, P. obscura Krasske, P. viridiformis Krammer, P. lundii Hustedt, and P. viridis (Nitzsch) Ehrenberg occurred at most of the investigated sites. Eighteen taxa were considered as new to Polish flora. Some taxa are very rare in Poland and Europe and are found in only a few localities. Eight taxa are listed on the Polish Red List of Algae, including six taxa classified as endangered (E): P. nobilis (Ehrenberg) Ehrenberg, P. nodosa (Ehrenberg) W. Smith, P. subrupestris Hantzsch, P. schoenfelderii Krammer, P. subgibba Krammer and P. viridiformis Krammer.
Eveline Pinseel - One of the best experts on this subject based on the ideXlab platform.
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a polyphasic approach to the delimitation of diatom species a case study for the genus Pinnularia bacillariophyta
Journal of Phycology, 2019Co-Authors: Jan Kollár, Aloisie Poulíčková, Caroline Souffreau, Pieter Vanormelingen, Eveline Pinseel, Petr Dvořák, Wim VyvermanAbstract:Diatoms are one of the most abundant and arguably the most species-rich group of protists. Diatom species delimitation has often been based exclusively on the recognition of morphological discontinuities without investigation of other lines of evidence. Even though DNA sequences and reproductive experiments have revealed several examples of (pseudo)cryptic diversity, our understanding of diatom species boundaries and diversity remains limited. The cosmopolitan pennate raphid diatom genus Pinnularia represents one of the most taxon-rich diatom genera. In this study, we focused on the delimitation of species in one of the major clades of the genus, the Pinnularia subgibba group, based on 105 strains from a worldwide origin. We compared genetic distances between the sequences of seven molecular markers and selected the most variable pair, the mitochondrial cox1 and nuclear encoded LSU rDNA, to formulate a primary hypothesis on the species limits using three single-locus automated species delimitation methods. We compared the DNA-based primary hypotheses with morphology and with other available lines of evidence. The results indicate that our data set comprised 15 species of the P. subgibba group. The vast majority of these taxa have an uncertain taxonomic identity, suggesting that several may be unknown to science and/or members of (pseudo)cryptic species complexes within the P. subgibba group.
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Pinnularia subcatenaborealis sp. nov. (Bacillariophyta) a new chain-forming diatom species from King George Island (Maritime Antarctica)
Phytotaxa, 2018Co-Authors: Natalia Kochman-kędziora, Eveline Pinseel, Mateusz Rybak, Teresa Noga, Maria Olech, Bart Van De VijverAbstract:During a survey conducted on the freshwater diatom flora of small shallow pools on the Ecology Glacier forefield (King George Island, Maritime Antarctic Region), an unknown spine-bearing chain-forming Pinnularia species, belonging to the Pinnularia borealis species complex, was found. Although it closely resembles the recently described Pinnularia catenaborealis from James Ross Island and Vega Island (Antarctic Peninsula), a unique set of morphological characteristics revealed in both light and scanning electron microscopy clearly discriminates the specimens of King George Island as a new species. Pinnularia subcatenaborealis Kochman-Kedziora, Pinseel & Van de Vijver sp. nov. can be distinguished from P. catenaborealis by an overall smaller valve size, the presence of irregularly formed silica outgrowths on the mantle and small, irregular plates located near the apices. The new taxon is so far only recorded from a small pool with circumneutral pH and very low conductivity.
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Pinnularia catenaborealis sp. nov. (Bacillariophyceae), a unique chain-forming diatom species from James Ross Island and Vega Island (Maritime Antarctica)
Phycologia, 2017Co-Authors: Eveline Pinseel, Pieter Vanormelingen, Wim Vyverman, Kateřina Kopalova, Eva Hejduková, Bart Van De VijverAbstract:Abstract: A recent detailed survey of the Maritime Antarctic diatom flora using a fine-grained taxonomy resulted in the description of many new species of Pinnularia in general and the section Distantes, including the P. borealis species complex, in particular. Moreover, DNA-based studies of P. borealis revealed that many more species need to be described within this complex. During a survey of the freshwater littoral diatom flora of James Ross Island (Ulu Peninsula) and Vega Island in Maritime Antarctica, a previously unknown chain-forming species in the P. borealis species complex of section Distantes was cultured from three different localities. Molecular phylogenies based on the nuclear-encoded D1–D3 large-subunit ribosomal DNA and plastid rbcL genes revealed that all cultures belong to a distinct highly supported lineage within the P. borealis species complex. Pinnularia catenaborealis sp. nov. is characterised by the presence of small spines located on a raised, thin silica ridge that almost entirel...
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Pinnularia borealis: disentangling the evolutionary history of a terrestrial diatom using genetics, fossils and ecophysiological data
2016Co-Authors: Caroline Souffreau, Pieter Vanormelingen, Koen Sabbe, Eveline Pinseel, Elie Verleyen, Wim VyvermanAbstract:Pinnularia borealis Ehrenberg is a terrestrial diatom, commonly found in moist soils and temporary freshwater habitats all over the world, including the (sub)Antarctic. Given the widespread (pseudo)cryptic species diversity in diatoms and the restricted distribution patterns of many (sub)Antarctic diatoms revealed by dedicated morphological studies, we asked whether Pinnularia borealis is indeed a single species and started reconstructing the evolutionary history of this cosmopolitan diatom. We observed that, unlike freshwater diatoms, resting cells of P. borealis are tolerant for at least short periods of desiccation, suggesting that airborne dispersal is possible which may limit opportunities for allopatric speciation. Nevertheless, molecular phylogenies based on the plastid gene rbcL and the nuclear 28S rDNA (D1-D3 region) revealed that P. borealis consists of multiple lineages, including a distinct continental Antarctic lineage. Ongoing work includes the addition of isolates from the maritime Antarctic and the (sub)Antarctic Marion Island. A molecular clock for Pinnularia calibrated by fossil data estimates the age of P. borealis at 35.8 (30-47) million years (Ma), and the continental Antarctic lineage at 7.8 (2-15) Ma. Compared to the lineages from non-polar regions, the continental Antarctic lineage of P. borealis has a lower optimal growth temperature and upper lethal temperature, indicating niche differentiation. The distinct molecular lineages, the old age of these lineages and the (partial) thermal niche differentiation suggest that long-distance dispersal is not common enough in P. borealis to prevent speciation, despite the desiccation tolerance of the resting cells, and indicate that besides freshwater diatoms, also terrestrial diatoms are not as ubiquitous as previously thought.
Wim Vyverman - One of the best experts on this subject based on the ideXlab platform.
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a polyphasic approach to the delimitation of diatom species a case study for the genus Pinnularia bacillariophyta
Journal of Phycology, 2019Co-Authors: Jan Kollár, Aloisie Poulíčková, Caroline Souffreau, Pieter Vanormelingen, Eveline Pinseel, Petr Dvořák, Wim VyvermanAbstract:Diatoms are one of the most abundant and arguably the most species-rich group of protists. Diatom species delimitation has often been based exclusively on the recognition of morphological discontinuities without investigation of other lines of evidence. Even though DNA sequences and reproductive experiments have revealed several examples of (pseudo)cryptic diversity, our understanding of diatom species boundaries and diversity remains limited. The cosmopolitan pennate raphid diatom genus Pinnularia represents one of the most taxon-rich diatom genera. In this study, we focused on the delimitation of species in one of the major clades of the genus, the Pinnularia subgibba group, based on 105 strains from a worldwide origin. We compared genetic distances between the sequences of seven molecular markers and selected the most variable pair, the mitochondrial cox1 and nuclear encoded LSU rDNA, to formulate a primary hypothesis on the species limits using three single-locus automated species delimitation methods. We compared the DNA-based primary hypotheses with morphology and with other available lines of evidence. The results indicate that our data set comprised 15 species of the P. subgibba group. The vast majority of these taxa have an uncertain taxonomic identity, suggesting that several may be unknown to science and/or members of (pseudo)cryptic species complexes within the P. subgibba group.
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Pinnularia catenaborealis sp. nov. (Bacillariophyceae), a unique chain-forming diatom species from James Ross Island and Vega Island (Maritime Antarctica)
Phycologia, 2017Co-Authors: Eveline Pinseel, Pieter Vanormelingen, Wim Vyverman, Kateřina Kopalova, Eva Hejduková, Bart Van De VijverAbstract:Abstract: A recent detailed survey of the Maritime Antarctic diatom flora using a fine-grained taxonomy resulted in the description of many new species of Pinnularia in general and the section Distantes, including the P. borealis species complex, in particular. Moreover, DNA-based studies of P. borealis revealed that many more species need to be described within this complex. During a survey of the freshwater littoral diatom flora of James Ross Island (Ulu Peninsula) and Vega Island in Maritime Antarctica, a previously unknown chain-forming species in the P. borealis species complex of section Distantes was cultured from three different localities. Molecular phylogenies based on the nuclear-encoded D1–D3 large-subunit ribosomal DNA and plastid rbcL genes revealed that all cultures belong to a distinct highly supported lineage within the P. borealis species complex. Pinnularia catenaborealis sp. nov. is characterised by the presence of small spines located on a raised, thin silica ridge that almost entirel...
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Pinnularia borealis: disentangling the evolutionary history of a terrestrial diatom using genetics, fossils and ecophysiological data
2016Co-Authors: Caroline Souffreau, Pieter Vanormelingen, Koen Sabbe, Eveline Pinseel, Elie Verleyen, Wim VyvermanAbstract:Pinnularia borealis Ehrenberg is a terrestrial diatom, commonly found in moist soils and temporary freshwater habitats all over the world, including the (sub)Antarctic. Given the widespread (pseudo)cryptic species diversity in diatoms and the restricted distribution patterns of many (sub)Antarctic diatoms revealed by dedicated morphological studies, we asked whether Pinnularia borealis is indeed a single species and started reconstructing the evolutionary history of this cosmopolitan diatom. We observed that, unlike freshwater diatoms, resting cells of P. borealis are tolerant for at least short periods of desiccation, suggesting that airborne dispersal is possible which may limit opportunities for allopatric speciation. Nevertheless, molecular phylogenies based on the plastid gene rbcL and the nuclear 28S rDNA (D1-D3 region) revealed that P. borealis consists of multiple lineages, including a distinct continental Antarctic lineage. Ongoing work includes the addition of isolates from the maritime Antarctic and the (sub)Antarctic Marion Island. A molecular clock for Pinnularia calibrated by fossil data estimates the age of P. borealis at 35.8 (30-47) million years (Ma), and the continental Antarctic lineage at 7.8 (2-15) Ma. Compared to the lineages from non-polar regions, the continental Antarctic lineage of P. borealis has a lower optimal growth temperature and upper lethal temperature, indicating niche differentiation. The distinct molecular lineages, the old age of these lineages and the (partial) thermal niche differentiation suggest that long-distance dispersal is not common enough in P. borealis to prevent speciation, despite the desiccation tolerance of the resting cells, and indicate that besides freshwater diatoms, also terrestrial diatoms are not as ubiquitous as previously thought.
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A time-calibrated multi-gene phylogeny of the diatom genus Pinnularia.
Molecular phylogenetics and evolution, 2011Co-Authors: Caroline Souffreau, David G. Mann, Bart Van De Vijver, Heroen Verbruggen, Alexander P. Wolfe, Pieter Vanormelingen, Peter A. Siver, Eileen J. Cox, Koen Sabbe, Wim VyvermanAbstract:Pinnularia is an ecologically important and species-rich genus of freshwater diatoms (Bacillariophyceae) showing considerable variation in frustule morphology. Interspecific evolutionary relationships were inferred for 36 Pinnularia taxa using a five-locus dataset. A range of fossil taxa, including newly discov- ered Middle Eocene forms of Pinnularia, was used to calibrate a relaxed molecular clock analysis and investigate temporal aspects of the genus' diversification. The multi-gene approach resulted in a well- resolved phylogeny of three major clades and several subclades that were frequently, but not universally, delimited by valve morphology. The genus Caloneis was not recovered as monophyletic, confirming that, as currently delimited, this genus is not evolutionarily meaningful and should be merged with Pinnularia. The Pinnularia-Caloneis complex is estimated to have diverged between the Upper Cretaceous and the early Eocene, implying a ghost range of at least 10 million year (Ma) in the fossil record.
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Pinnularia sakulensis and Rhopalodia tholulata: two new diatoms (Bacillariophyta) from Papua New Guinea
Belgian Journal of Botany, 1991Co-Authors: Wim Vyverman, Philippe CompèreAbstract:Two new diatoms, Pinnularia sakulensis and Rhopalodia tholulata are described from Papua New Guinea. A revised key to the identification of the Rhopalodia taxa is given.
