Pub Date : 2022-01-17DOI: 10.1080/09670262.2021.2014982
Kornelia Duchnik, J. Białczyk, E. Chrapusta-Srebrny, Ariel Kaminski, B. Bober
ABSTRACT The increase in frequency and prevalence of cylindrospermopsin (CYN)-producing cyanobacteria blooms have become a growing problem worldwide. Therefore, the long-term effects of CYN on the physiological processes of the macrophyte, Lemna trisulca, were examined. During a 5-day exposure to a range of CYN concentrations (0.5, 1 and 5 μg ml−1), the low levels of stress experienced by L. trisulca stimulated its growth rate and photosynthesis and led to an increase in the synthesis of photosynthetic pigments. In turn, it was shown that a 3-week exposure to the highest tested CYN concentration (5 μg ml−1) resulted in the inhibition of biomass accumulation (by 7.6%) compared with that of the control plants, but necrosis and chlorosis were not observed. A negative correlation with the concentration of carotenoids was also observed, which may suggest that the antioxidant mechanisms of L. trisulca are effective only up to a certain CYN concentration. An increase in protein content in the tissues of macrophytes treated with concentrations of CYN ranging from 0.5 to 5 μg ml−1 indicates that the toxin did not inhibit protein synthesis but increased the metabolism of L. trisulca, potentially to provide energy for defence. The toxin also affects the homeostasis of mineral ions in cells. This is the first description of the physiological response of L. trisulca to the long-term effects of a wide range of CYN concentrations.
{"title":"The long-term exposure of cyanotoxin, cylindrospermopsin, on the macrophyte Lemna trisulca","authors":"Kornelia Duchnik, J. Białczyk, E. Chrapusta-Srebrny, Ariel Kaminski, B. Bober","doi":"10.1080/09670262.2021.2014982","DOIUrl":"https://doi.org/10.1080/09670262.2021.2014982","url":null,"abstract":"ABSTRACT The increase in frequency and prevalence of cylindrospermopsin (CYN)-producing cyanobacteria blooms have become a growing problem worldwide. Therefore, the long-term effects of CYN on the physiological processes of the macrophyte, Lemna trisulca, were examined. During a 5-day exposure to a range of CYN concentrations (0.5, 1 and 5 μg ml−1), the low levels of stress experienced by L. trisulca stimulated its growth rate and photosynthesis and led to an increase in the synthesis of photosynthetic pigments. In turn, it was shown that a 3-week exposure to the highest tested CYN concentration (5 μg ml−1) resulted in the inhibition of biomass accumulation (by 7.6%) compared with that of the control plants, but necrosis and chlorosis were not observed. A negative correlation with the concentration of carotenoids was also observed, which may suggest that the antioxidant mechanisms of L. trisulca are effective only up to a certain CYN concentration. An increase in protein content in the tissues of macrophytes treated with concentrations of CYN ranging from 0.5 to 5 μg ml−1 indicates that the toxin did not inhibit protein synthesis but increased the metabolism of L. trisulca, potentially to provide energy for defence. The toxin also affects the homeostasis of mineral ions in cells. This is the first description of the physiological response of L. trisulca to the long-term effects of a wide range of CYN concentrations.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"57 1","pages":"422 - 432"},"PeriodicalIF":2.4,"publicationDate":"2022-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49595433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-12DOI: 10.1080/09670262.2021.2007420
A. Stanojković, Svatopluk Skoupý, P. Hašler, A. Poulíčková, P. Dvořák
ABSTRACT Despite the extensive diversity of bacteria and their importance to the fundamental functioning of terrestrial ecosystems, their distribution patterns are still not fully known. To fill the gap and further understand the biogeographic patterns in bacteria, we investigated the phylogeographic structure and the underlying drivers of diversification among populations of the cyanobacterium Microcoleus spp. The phylogenetic history was reconstructed using 16S rRNA genes and the 16S–23S internal transcribed spacer (ITS) of 495 Microcoleus spp. isolates. Ancestral area and state reconstruction was employed to investigate the distributional and ecological patterns within Microcoleus. Both isolation by distance and isolation by environment were tested with distance matrices analysis. The phylogenetic signal tests were conducted in order to assess the influence of the climatic preferences on the diversification of Microcoleus isolates. The distribution and phylogenetic diversification of Microcoleus are driven by both isolation by distance and environment, leading to at least 13 distinct lineages that could represent novel cyanobacterial species. Microcoleus spp. exhibited a distinct phylogeographic structure within the respective lineages. The ancestral area and state reconstruction revealed that Microcoleus most likely arose in Europe in terrestrial habitats. The phylogenetic signal showed that the phylogeny significantly affects the climatic preferences of Microcoleus strains. Geographic distance and contemporary climatic conditions play significant roles in shaping the distribution and diversification of Microcoleus. The observed patterns of distribution may shift in the future due to the impact of climate change. Highlights Microcoleus exhibited distinct phylogeographic structure within the respective lineages. Geographic and environmental heterogeneity affect Microcoleus distribution and diversification. Genetically distinct lineages coexist at the same site.
{"title":"Geography and climate drive the distribution and diversification of the cosmopolitan cyanobacterium Microcoleus (Oscillatoriales, Cyanobacteria)","authors":"A. Stanojković, Svatopluk Skoupý, P. Hašler, A. Poulíčková, P. Dvořák","doi":"10.1080/09670262.2021.2007420","DOIUrl":"https://doi.org/10.1080/09670262.2021.2007420","url":null,"abstract":"ABSTRACT Despite the extensive diversity of bacteria and their importance to the fundamental functioning of terrestrial ecosystems, their distribution patterns are still not fully known. To fill the gap and further understand the biogeographic patterns in bacteria, we investigated the phylogeographic structure and the underlying drivers of diversification among populations of the cyanobacterium Microcoleus spp. The phylogenetic history was reconstructed using 16S rRNA genes and the 16S–23S internal transcribed spacer (ITS) of 495 Microcoleus spp. isolates. Ancestral area and state reconstruction was employed to investigate the distributional and ecological patterns within Microcoleus. Both isolation by distance and isolation by environment were tested with distance matrices analysis. The phylogenetic signal tests were conducted in order to assess the influence of the climatic preferences on the diversification of Microcoleus isolates. The distribution and phylogenetic diversification of Microcoleus are driven by both isolation by distance and environment, leading to at least 13 distinct lineages that could represent novel cyanobacterial species. Microcoleus spp. exhibited a distinct phylogeographic structure within the respective lineages. The ancestral area and state reconstruction revealed that Microcoleus most likely arose in Europe in terrestrial habitats. The phylogenetic signal showed that the phylogeny significantly affects the climatic preferences of Microcoleus strains. Geographic distance and contemporary climatic conditions play significant roles in shaping the distribution and diversification of Microcoleus. The observed patterns of distribution may shift in the future due to the impact of climate change. Highlights Microcoleus exhibited distinct phylogeographic structure within the respective lineages. Geographic and environmental heterogeneity affect Microcoleus distribution and diversification. Genetically distinct lineages coexist at the same site.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"57 1","pages":"396 - 405"},"PeriodicalIF":2.4,"publicationDate":"2022-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48274308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-05DOI: 10.1080/09670262.2021.2003867
Maria Irisvalda Leal Gondim Cavalcanti, Patricia María González Sánchez, M. Fujii
ABSTRACT Stranded seaweeds are reported worldwide; along the Brazilian coast, the occurrence of beach-cast seaweeds is increasing. In this study the diversity, coverage and biomass of beach-cast seaweeds were compared on the north-eastern (NE) and south-eastern (SE) coasts of Brazil. In total 110 taxa were identified: 80 Rhodophyceae, 13 Phaeophyceae and 17 Chlorophyceae. While the NE coast had higher species richness, the SE beaches exhibited higher coverage and biomass, predominantly Phaeophytes within the Dictyotales. The identified taxa were attributed to five functional-form groups and their respective frequencies were calculated and analysed. In Brazil, corticated species displayed the highest frequency at all study sites, especially Emboaca Beach, whereas the corticated foliose group was more frequent on Candeias, Itaoca and Pontal Beaches. A permutational analysis of variance revealed significant differences in coverage and biomass of the macroalgal assemblages across beaches. A homogeneity of multivariate dispersions indicated that these parameters also differed significantly between the NE and SE coasts, with a marked dissimilarity between the beaches studied. Our results will contribute to a better understanding of the biodiversity and biomass of beach-cast seaweeds for possible future economic use (e.g. as fertilizer) in a region where local incomes are low.
{"title":"Comparison of the diversity and biomass of beach-cast seaweeds from NE and SE Brazil","authors":"Maria Irisvalda Leal Gondim Cavalcanti, Patricia María González Sánchez, M. Fujii","doi":"10.1080/09670262.2021.2003867","DOIUrl":"https://doi.org/10.1080/09670262.2021.2003867","url":null,"abstract":"ABSTRACT Stranded seaweeds are reported worldwide; along the Brazilian coast, the occurrence of beach-cast seaweeds is increasing. In this study the diversity, coverage and biomass of beach-cast seaweeds were compared on the north-eastern (NE) and south-eastern (SE) coasts of Brazil. In total 110 taxa were identified: 80 Rhodophyceae, 13 Phaeophyceae and 17 Chlorophyceae. While the NE coast had higher species richness, the SE beaches exhibited higher coverage and biomass, predominantly Phaeophytes within the Dictyotales. The identified taxa were attributed to five functional-form groups and their respective frequencies were calculated and analysed. In Brazil, corticated species displayed the highest frequency at all study sites, especially Emboaca Beach, whereas the corticated foliose group was more frequent on Candeias, Itaoca and Pontal Beaches. A permutational analysis of variance revealed significant differences in coverage and biomass of the macroalgal assemblages across beaches. A homogeneity of multivariate dispersions indicated that these parameters also differed significantly between the NE and SE coasts, with a marked dissimilarity between the beaches studied. Our results will contribute to a better understanding of the biodiversity and biomass of beach-cast seaweeds for possible future economic use (e.g. as fertilizer) in a region where local incomes are low.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"57 1","pages":"367 - 376"},"PeriodicalIF":2.4,"publicationDate":"2022-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42318163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-23DOI: 10.1080/09670262.2021.1995630
R. V. Barbosa, S. Halac, E. Schwindt, M. Tatián
Abstract The changes within and between seasons in phytoplankton composition and abundance determine the carbon biomass available for upper levels of the food web. Temporal changes in phytoplankton community and environmental parameters in a port in Puerto Madryn, Southwest Atlantic were analysed. During an annual period (2011–2012), samples of surface seawater were collected approximately monthly. We determined phytoplankton community structure (species composition and abundance) and biomass (determined by carbon content and chlorophyll a (Chl a)). Water temperature, salinity and transparency were measured when sampling the surface water and local meteorological data were considered. The main groups observed were diatoms (Bacillariophyta; the most abundant during the concentration peaks of Chl a), dinoflagellates (Dinophyta) and flagellates, which mainly included species of Cryptophyta and Chlorophyta. Diatoms exhibited blooms in March (summer–autumn) and September (spring), represented by Skeletonema costatum and Pseudo-nitzschia spp. respectively. Dinoflagellates contributed to the highest carbon biomass, with peaks in January (summer) and April (autumn), exemplified by Prorocentrum micans and Scrippsiella acuminata, respectively. Temporal differences in community composition were related to the seasonal changes in temperature, solar irradiance, precipitation, salinity and wind velocity. The environmental conditions seem not only to determine the species composition but also cell size distribution: nanoplanktonic (≤ 20 µm) species dominated mainly during late spring, summer and early winter while microplanktonic species (> 20 µm) during late winter and early spring. Our results showed within-season changes and show that not only Chl a, but also carbon content can be considered, as the former is a biased estimator of phytoplankton biomass. This study provides the first seasonally resolved estimation in the area of the carbon biomass available for upper levels of the food web and a necessary information for future scenarios prediction. HIGHLIGHTS• Two diatom blooms were followed by an increase in dinoflagellate abundance.• Annual environmental conditions drive the phytoplankton community structure.• First seasonally estimation of autotrophic biomass availability for Patagonian trophic web.
{"title":"Seasonality of phytoplankton community and dynamics of autotrophic carbon in a cold temperate port (Argentina)","authors":"R. V. Barbosa, S. Halac, E. Schwindt, M. Tatián","doi":"10.1080/09670262.2021.1995630","DOIUrl":"https://doi.org/10.1080/09670262.2021.1995630","url":null,"abstract":"Abstract The changes within and between seasons in phytoplankton composition and abundance determine the carbon biomass available for upper levels of the food web. Temporal changes in phytoplankton community and environmental parameters in a port in Puerto Madryn, Southwest Atlantic were analysed. During an annual period (2011–2012), samples of surface seawater were collected approximately monthly. We determined phytoplankton community structure (species composition and abundance) and biomass (determined by carbon content and chlorophyll a (Chl a)). Water temperature, salinity and transparency were measured when sampling the surface water and local meteorological data were considered. The main groups observed were diatoms (Bacillariophyta; the most abundant during the concentration peaks of Chl a), dinoflagellates (Dinophyta) and flagellates, which mainly included species of Cryptophyta and Chlorophyta. Diatoms exhibited blooms in March (summer–autumn) and September (spring), represented by Skeletonema costatum and Pseudo-nitzschia spp. respectively. Dinoflagellates contributed to the highest carbon biomass, with peaks in January (summer) and April (autumn), exemplified by Prorocentrum micans and Scrippsiella acuminata, respectively. Temporal differences in community composition were related to the seasonal changes in temperature, solar irradiance, precipitation, salinity and wind velocity. The environmental conditions seem not only to determine the species composition but also cell size distribution: nanoplanktonic (≤ 20 µm) species dominated mainly during late spring, summer and early winter while microplanktonic species (> 20 µm) during late winter and early spring. Our results showed within-season changes and show that not only Chl a, but also carbon content can be considered, as the former is a biased estimator of phytoplankton biomass. This study provides the first seasonally resolved estimation in the area of the carbon biomass available for upper levels of the food web and a necessary information for future scenarios prediction. HIGHLIGHTS• Two diatom blooms were followed by an increase in dinoflagellate abundance.• Annual environmental conditions drive the phytoplankton community structure.• First seasonally estimation of autotrophic biomass availability for Patagonian trophic web.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"57 1","pages":"343 - 356"},"PeriodicalIF":2.4,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48646134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-09DOI: 10.1080/09670262.2021.1987527
R. Romanov, A. Nikulin, V. Nikulin, A. Gontcharov
Abstract European paddy fields harbour a morphologically and genetically unusual charophyte that is distant from any other European species. The new species, Chara oryzae from Mediterranean rice fields, was described using an integrated approach, including scanning electron microscopy and molecular phylogenetics. The combination of monoecy, a triplostichous stem cortex with solitary spine cells, haplostephanous stipulodes, abbreviated branchlet segments with their mostly incomplete diplostichous cortication, and long undifferentiated part of a branchlet distinguish C. oryzae from other Chara species described to date. A unique set of phenotypic characteristics and lack of affinity to Chara sections and subsections prompted us to accommodate the species in a new section Corillionia of the subgenus Chara. C. oryzae could be recognized as a species non-native to Europe because it is known only in rice fields, which have been maintained for centuries in the region studied. HIGHLIGHTS • European paddy fields harbour a charophyte with unusual morphology and genotype distant from any European species.• A new species, Chara oryzae, is described using an integrated approach.• A new section, Corillionia, of the subgenus Chara is proposed.
{"title":"New species Chara oryzae and a new section Corillionia of Chara (Charales, Charophyceae) from European Mediterranean rice fields","authors":"R. Romanov, A. Nikulin, V. Nikulin, A. Gontcharov","doi":"10.1080/09670262.2021.1987527","DOIUrl":"https://doi.org/10.1080/09670262.2021.1987527","url":null,"abstract":"Abstract European paddy fields harbour a morphologically and genetically unusual charophyte that is distant from any other European species. The new species, Chara oryzae from Mediterranean rice fields, was described using an integrated approach, including scanning electron microscopy and molecular phylogenetics. The combination of monoecy, a triplostichous stem cortex with solitary spine cells, haplostephanous stipulodes, abbreviated branchlet segments with their mostly incomplete diplostichous cortication, and long undifferentiated part of a branchlet distinguish C. oryzae from other Chara species described to date. A unique set of phenotypic characteristics and lack of affinity to Chara sections and subsections prompted us to accommodate the species in a new section Corillionia of the subgenus Chara. C. oryzae could be recognized as a species non-native to Europe because it is known only in rice fields, which have been maintained for centuries in the region studied. HIGHLIGHTS • European paddy fields harbour a charophyte with unusual morphology and genotype distant from any European species.• A new species, Chara oryzae, is described using an integrated approach.• A new section, Corillionia, of the subgenus Chara is proposed.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"57 1","pages":"328 - 342"},"PeriodicalIF":2.4,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43183889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-30DOI: 10.1080/09670262.2021.1970234
J. Cañavate, C. Fernández-Díaz
Abstract Studies on the influence of salinity on microalgal lipids have focused mainly on chlorophyte species and knowledge about photosynthetic secondary endosymbionts is limited. Haptophytes exemplify this situation and represent an interesting model to advance knowledge about the high phylogenetic variability of microalgae in their response to salinity. The estuarine Pavlovophyceae Diacronema vlkianum underwent particular lipid class and fatty acid changes under the effect of salinity. Variability due to salinity was higher in the fatty acid profile compared with that of the lipid class profile. Triacylglycerols decreased with salinity in actively growing cells and increased only when salinity rose to 50 and cell growth ceased. Hypersalinity caused a slight, although significant, sulpholipid decrease and a 4-fold increase in phosphatidylglycerol, suggesting a key role for this phospholipid in salt tolerance. Conversely, the betaine lipid diacylglycerol hydroxymethyl-N,N,N-trimethyl-β-alanine was specifically decreased with high salinity. The fatty acids that decreased the most with salinity were 14:0, 16:1n-7, 20:4n-6, 20:5n-3 and 22:6n-3, while higher levels of 16:1n-9, 17:1, 18:2n-6 and 18:3n-3 were induced by high salinity. Despite fatty acid changes, the unsaturation index did not vary with salinity, but nutritional value of D. vlkianum decreased at a salinity of 50 due to a lower presence of 20-C polyunsaturated fatty acids. This pattern of lipid variation in D. vlkianum with salinity has not been described in any other microalgae. Although D. vlkianum grows within a wide salinity range, production of nutritional and functional lipids is more favourable at low salinity values.
{"title":"Salinity induces unique changes in lipid classes and fatty acids of the estuarine haptophyte Diacronema vlkianum","authors":"J. Cañavate, C. Fernández-Díaz","doi":"10.1080/09670262.2021.1970234","DOIUrl":"https://doi.org/10.1080/09670262.2021.1970234","url":null,"abstract":"Abstract Studies on the influence of salinity on microalgal lipids have focused mainly on chlorophyte species and knowledge about photosynthetic secondary endosymbionts is limited. Haptophytes exemplify this situation and represent an interesting model to advance knowledge about the high phylogenetic variability of microalgae in their response to salinity. The estuarine Pavlovophyceae Diacronema vlkianum underwent particular lipid class and fatty acid changes under the effect of salinity. Variability due to salinity was higher in the fatty acid profile compared with that of the lipid class profile. Triacylglycerols decreased with salinity in actively growing cells and increased only when salinity rose to 50 and cell growth ceased. Hypersalinity caused a slight, although significant, sulpholipid decrease and a 4-fold increase in phosphatidylglycerol, suggesting a key role for this phospholipid in salt tolerance. Conversely, the betaine lipid diacylglycerol hydroxymethyl-N,N,N-trimethyl-β-alanine was specifically decreased with high salinity. The fatty acids that decreased the most with salinity were 14:0, 16:1n-7, 20:4n-6, 20:5n-3 and 22:6n-3, while higher levels of 16:1n-9, 17:1, 18:2n-6 and 18:3n-3 were induced by high salinity. Despite fatty acid changes, the unsaturation index did not vary with salinity, but nutritional value of D. vlkianum decreased at a salinity of 50 due to a lower presence of 20-C polyunsaturated fatty acids. This pattern of lipid variation in D. vlkianum with salinity has not been described in any other microalgae. Although D. vlkianum grows within a wide salinity range, production of nutritional and functional lipids is more favourable at low salinity values.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"57 1","pages":"297 - 317"},"PeriodicalIF":2.4,"publicationDate":"2021-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42271448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-12DOI: 10.1080/09670262.2021.1966838
L. Arin, Albert Reñé, R. Gallisai, D. Sarno, E. Garcés, M. Estrada
ABSTRACT The majority of species of the highly diverse genus Chaetoceros are described as chain-forming, although several species are described as strictly solitary (such as C. tenuissimus) or having an alternate solitary and a chain-forming phase during their life history (such as C. salsugineus). In this study, the diversity of small forms of Chaetoceros from the NW Mediterranean coastal waters was explored through the morphological and molecular characterization of four different strains belonging to two distinct species. Based on their morphology, three of the strains were identified as C. salsugineus (Takano, 1983). The SSU and LSU rDNA sequences represented the first available for well-characterized C. salsugineus strains and were 96.6–100% similar to publicly available C. tenuissimus (Meunier, 1913) sequences. Both species share the same morphological features, such as setae and ultrastructure of the valves, as well as the rimoportula characteristics. In addition, the morphology of the solitary form of C. salsugineus matched with that of C. tenuissimus. Here, we propose the two species as synonyms (the name C. tenuissimus prevailing as it has priority for this taxon), emend the original description and designate an epitype. The fourth strain was identified as C. olympicus sp. nov., a new species, which alternates solitary and chain-forming forms within its life history. The main differential characteristics of this species are the absence of rimoportula both in terminal and intercalary valves, the setae ultrastructure, which is thin and circular in cross-section with a few, slightly twisted, rows of small rectangular poroids and some spirally arranged spines, and the morphology of the resting spores, with primary valve vaulted and covered with short to medium-sized spines, and secondary valve smaller, rounded and smooth. A comparison of C. tenuissimus and C. olympicus with other species as well as information on their life cycle and ecology is also provided. HIGHLIGHTS • Description of a new Chaetoceros species: C. olympicus. • Proposal that C. tenuissimus and C. salsugineus are synonyms. • Importance of morphological variability in life cycles for species identification.
{"title":"Taxonomic relationship between two small-sized Chaetoceros species (Bacillariophyta): C. tenuissimus and C. salsugineus, and comparison with C. olympicus sp. nov. from Catalan coastal waters (NW Mediterranean)","authors":"L. Arin, Albert Reñé, R. Gallisai, D. Sarno, E. Garcés, M. Estrada","doi":"10.1080/09670262.2021.1966838","DOIUrl":"https://doi.org/10.1080/09670262.2021.1966838","url":null,"abstract":"ABSTRACT The majority of species of the highly diverse genus Chaetoceros are described as chain-forming, although several species are described as strictly solitary (such as C. tenuissimus) or having an alternate solitary and a chain-forming phase during their life history (such as C. salsugineus). In this study, the diversity of small forms of Chaetoceros from the NW Mediterranean coastal waters was explored through the morphological and molecular characterization of four different strains belonging to two distinct species. Based on their morphology, three of the strains were identified as C. salsugineus (Takano, 1983). The SSU and LSU rDNA sequences represented the first available for well-characterized C. salsugineus strains and were 96.6–100% similar to publicly available C. tenuissimus (Meunier, 1913) sequences. Both species share the same morphological features, such as setae and ultrastructure of the valves, as well as the rimoportula characteristics. In addition, the morphology of the solitary form of C. salsugineus matched with that of C. tenuissimus. Here, we propose the two species as synonyms (the name C. tenuissimus prevailing as it has priority for this taxon), emend the original description and designate an epitype. The fourth strain was identified as C. olympicus sp. nov., a new species, which alternates solitary and chain-forming forms within its life history. The main differential characteristics of this species are the absence of rimoportula both in terminal and intercalary valves, the setae ultrastructure, which is thin and circular in cross-section with a few, slightly twisted, rows of small rectangular poroids and some spirally arranged spines, and the morphology of the resting spores, with primary valve vaulted and covered with short to medium-sized spines, and secondary valve smaller, rounded and smooth. A comparison of C. tenuissimus and C. olympicus with other species as well as information on their life cycle and ecology is also provided. HIGHLIGHTS • Description of a new Chaetoceros species: C. olympicus. • Proposal that C. tenuissimus and C. salsugineus are synonyms. • Importance of morphological variability in life cycles for species identification.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"57 1","pages":"277 - 296"},"PeriodicalIF":2.4,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49635437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-04DOI: 10.1080/09670262.2021.1950839
Luana Miranda Coutinho, Fernanda Penelas Gomes, M. Nasri Sissini, Talita Vieira-Pinto, Maria Carolina Muller de Oliveira Henriques, M. C. Oliveira, Paulo Antunes Horta, Maria Beatriz Barbosa de Barros Barreto
ABSTRACT Molecular studies have revealed cryptic diversity and polyphyly in the genus Lithothamnion. In this study we aimed to investigate the diversity and phylogeny of specimens that are morphologically described as Lithothamnion based on extensive collections along the Brazilian coast and an integrative taxonomic approach. Our results led to the proposal of Roseolithon gen. nov. belonging to the subfamily Melobesioideae. This new genus is described from the tropical north-western Atlantic and warm temperate south-western Atlantic specimens, based on phylogenetic analyses of psbA, rbcL-3P, COI-5P and SSU rDNA molecular markers, species delimitation methods, genetic divergence and morpho-anatomical observations. The integrative approach led us to find a set of morphological features that characterize Roseolithon: (i) thallus organization monomerous with plumose hypothallus (non-coaxial); (ii) flared epithallial cells; (iii) subepithallial cells varying in size and may be shorter, approximately equal to or longer than those subtending them; (iv) cells of adjacent filaments linked by fusions; (v) tetra/bisporangial conceptacle chambers multiporate; and (vi) the presence of pore canals bordered by rosette cells in depressions giving the surface a pitted appearance. Depending on the species, this pitted appearance occurs due to the sunken or disintegrated rosette cell roofs. The grade of the degeneration of the rosette cell roofs characterizes the species of this genus. The new genus Roseolithon is composed of at least 18 species, of which we describe seven new species: Roseolithon tupii, R. tamoioi, R. tremembei, R. potiguarae, R. karaiborum, R. purii and R. goytacae. Highlights Phylogenetic analyses revealed Lithothamnion to be a polyFphyletic genus. Integrative taxonomy enabled the description of a new genus Roseolithon. Morpho-anatomy does not reflect molecular phylogeny of non-geniculate coralline algae.
{"title":"Cryptic diversity in non-geniculate coralline algae: a new genus Roseolithon (Hapalidiales, Rhodophyta) and seven new species from the Western Atlantic","authors":"Luana Miranda Coutinho, Fernanda Penelas Gomes, M. Nasri Sissini, Talita Vieira-Pinto, Maria Carolina Muller de Oliveira Henriques, M. C. Oliveira, Paulo Antunes Horta, Maria Beatriz Barbosa de Barros Barreto","doi":"10.1080/09670262.2021.1950839","DOIUrl":"https://doi.org/10.1080/09670262.2021.1950839","url":null,"abstract":"ABSTRACT Molecular studies have revealed cryptic diversity and polyphyly in the genus Lithothamnion. In this study we aimed to investigate the diversity and phylogeny of specimens that are morphologically described as Lithothamnion based on extensive collections along the Brazilian coast and an integrative taxonomic approach. Our results led to the proposal of Roseolithon gen. nov. belonging to the subfamily Melobesioideae. This new genus is described from the tropical north-western Atlantic and warm temperate south-western Atlantic specimens, based on phylogenetic analyses of psbA, rbcL-3P, COI-5P and SSU rDNA molecular markers, species delimitation methods, genetic divergence and morpho-anatomical observations. The integrative approach led us to find a set of morphological features that characterize Roseolithon: (i) thallus organization monomerous with plumose hypothallus (non-coaxial); (ii) flared epithallial cells; (iii) subepithallial cells varying in size and may be shorter, approximately equal to or longer than those subtending them; (iv) cells of adjacent filaments linked by fusions; (v) tetra/bisporangial conceptacle chambers multiporate; and (vi) the presence of pore canals bordered by rosette cells in depressions giving the surface a pitted appearance. Depending on the species, this pitted appearance occurs due to the sunken or disintegrated rosette cell roofs. The grade of the degeneration of the rosette cell roofs characterizes the species of this genus. The new genus Roseolithon is composed of at least 18 species, of which we describe seven new species: Roseolithon tupii, R. tamoioi, R. tremembei, R. potiguarae, R. karaiborum, R. purii and R. goytacae. Highlights Phylogenetic analyses revealed Lithothamnion to be a polyFphyletic genus. Integrative taxonomy enabled the description of a new genus Roseolithon. Morpho-anatomy does not reflect molecular phylogeny of non-geniculate coralline algae.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"57 1","pages":"227 - 250"},"PeriodicalIF":2.4,"publicationDate":"2021-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59529206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-28DOI: 10.1080/09670262.2021.1964608
Á. Cuadrado, M. Sixto, R. Figueroa, I. Bravo, A. de Bustos
ABSTRACT Dinoflagellates are protists with exceptionally large genomes and chromosomes that lack nucleosomes. To date, information on their genome organization is scarce. Studies investigating the distribution of ribosomal RNA genes (rDNA) in plants and animals by fluorescence in situ hybridization (FISH) have provided important information to elucidate the genome organization and evolution of many species. In the present study, FISH was used to analyse the chromosomal organization of 45S and 5S rDNA and the extent of rDNA variation among five species of Gambierdiscus (G. australes, G. excentricus, G. silvae, G. carolinianus and G. caribaeus). The results, the intensity and location of the FISH signals, are summarized as follows: (1) All Gambierdiscus species have extremely high copy number of 45S rDNA repeat units arranged in a large nucleolus situated in the concave region of the typical interphasic bean-shaped nucleus. In addition, outside the large nucleolus, G. silvae and G. carolinianus have minor clusters of 45S rDNA repeats. (2) Many copies of 5S rDNA organized in one or a few clusters, depending on the species, are physically separated from the 45S rDNA but located close, peripherally, to the nucleolus. This nuclear organization is preserved during cell division. (3) Gambierdiscus australes was the species with the lowest 5S rDNA FISH signals clustered into a single site. In contrast, one major and several minor 5S rDNA clusters of FISH signals were observed in G. excentricus. We find that the species analysed can be differentiated by their species-specific FISH rDNA phenotypes demonstrating the usefulness of FISH in comparative cytogenomic studies of Gambierdiscus. In addition, using G. australes as a model, we demonstrate the usefulness of 45S and 5S rDNA as chromosomal markers to study dinomitosis, the atypical nuclear division that solely occurs in the class Dinophyceae.
{"title":"Comparative FISH mapping of 45S and 5S rDNA in the genus Gambierdiscus advances understanding of the cytogenetic diversity and mitosis of dinoflagellates","authors":"Á. Cuadrado, M. Sixto, R. Figueroa, I. Bravo, A. de Bustos","doi":"10.1080/09670262.2021.1964608","DOIUrl":"https://doi.org/10.1080/09670262.2021.1964608","url":null,"abstract":"ABSTRACT Dinoflagellates are protists with exceptionally large genomes and chromosomes that lack nucleosomes. To date, information on their genome organization is scarce. Studies investigating the distribution of ribosomal RNA genes (rDNA) in plants and animals by fluorescence in situ hybridization (FISH) have provided important information to elucidate the genome organization and evolution of many species. In the present study, FISH was used to analyse the chromosomal organization of 45S and 5S rDNA and the extent of rDNA variation among five species of Gambierdiscus (G. australes, G. excentricus, G. silvae, G. carolinianus and G. caribaeus). The results, the intensity and location of the FISH signals, are summarized as follows: (1) All Gambierdiscus species have extremely high copy number of 45S rDNA repeat units arranged in a large nucleolus situated in the concave region of the typical interphasic bean-shaped nucleus. In addition, outside the large nucleolus, G. silvae and G. carolinianus have minor clusters of 45S rDNA repeats. (2) Many copies of 5S rDNA organized in one or a few clusters, depending on the species, are physically separated from the 45S rDNA but located close, peripherally, to the nucleolus. This nuclear organization is preserved during cell division. (3) Gambierdiscus australes was the species with the lowest 5S rDNA FISH signals clustered into a single site. In contrast, one major and several minor 5S rDNA clusters of FISH signals were observed in G. excentricus. We find that the species analysed can be differentiated by their species-specific FISH rDNA phenotypes demonstrating the usefulness of FISH in comparative cytogenomic studies of Gambierdiscus. In addition, using G. australes as a model, we demonstrate the usefulness of 45S and 5S rDNA as chromosomal markers to study dinomitosis, the atypical nuclear division that solely occurs in the class Dinophyceae.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"57 1","pages":"264 - 276"},"PeriodicalIF":2.4,"publicationDate":"2021-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48793609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-21DOI: 10.1080/09670262.2021.1970235
H. Kawai, T. Hanyuda, E. Henry
ABSTRACT Molecular phylogeny based on concatenated sequences of chloroplast atpB, psaA, psbA, psbC and rbcL genes indicates that the filamentous brown alga Pilinia rimosa is phylogenetically distant from the Ectocarpales, in which it has been classified (as Waerniella lucifuga). In the tree, Pilinia was sister to the clade comprised of Ishige and Petroderma (Ishigeales) supported by high statistical values. Observations of unialgal P. rimosa cultures originating from Helgoland (Germany), England (UK), Woods Hole (USA) and Newfoundland (Canada) showed a direct type of life history with reproduction by characteristic unilocular zoidangia typically forming only four zoids. Despite the description of plurilocular zoidangia in Kuckuck’s account as well as in later publications, we conclude that those observations were based on misinterpretation of the very small unilocular zoidangia formed in series, often with longitudinal walls between zoidangia. Pilinia rimosa grows in caves or crevices in rocks, and on walls or wood pilings in deep shade in the upper intertidal and spray zone, and is therefore regarded as a marine species, but it could also survive and mature in freshwater medium. We propose the establishment of a new family Piliniaceae for Pilinia and place it in Ishigeales. Molecular and morphological analysis of the culture strains, SAG 124.79 and SAG 2381, identified as the euryhaline alga Porterinema fluviatile, indicated that SAG 124.79 is in fact P. rimosa. However, SAG 2381 is true P. fluviatile, also displaying the characteristic plurilocular zoidangia. Porterinema was shown to be a member of the Chordariaceae, Ectocarpales sensu lato.
{"title":"Transfer of Pilinia from Ectocarpales to Ishigeales (Phaeophyceae) with proposal of Piliniaceae fam. nov., and taxonomy of Porterinema in Ectocarpales","authors":"H. Kawai, T. Hanyuda, E. Henry","doi":"10.1080/09670262.2021.1970235","DOIUrl":"https://doi.org/10.1080/09670262.2021.1970235","url":null,"abstract":"ABSTRACT Molecular phylogeny based on concatenated sequences of chloroplast atpB, psaA, psbA, psbC and rbcL genes indicates that the filamentous brown alga Pilinia rimosa is phylogenetically distant from the Ectocarpales, in which it has been classified (as Waerniella lucifuga). In the tree, Pilinia was sister to the clade comprised of Ishige and Petroderma (Ishigeales) supported by high statistical values. Observations of unialgal P. rimosa cultures originating from Helgoland (Germany), England (UK), Woods Hole (USA) and Newfoundland (Canada) showed a direct type of life history with reproduction by characteristic unilocular zoidangia typically forming only four zoids. Despite the description of plurilocular zoidangia in Kuckuck’s account as well as in later publications, we conclude that those observations were based on misinterpretation of the very small unilocular zoidangia formed in series, often with longitudinal walls between zoidangia. Pilinia rimosa grows in caves or crevices in rocks, and on walls or wood pilings in deep shade in the upper intertidal and spray zone, and is therefore regarded as a marine species, but it could also survive and mature in freshwater medium. We propose the establishment of a new family Piliniaceae for Pilinia and place it in Ishigeales. Molecular and morphological analysis of the culture strains, SAG 124.79 and SAG 2381, identified as the euryhaline alga Porterinema fluviatile, indicated that SAG 124.79 is in fact P. rimosa. However, SAG 2381 is true P. fluviatile, also displaying the characteristic plurilocular zoidangia. Porterinema was shown to be a member of the Chordariaceae, Ectocarpales sensu lato.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"57 1","pages":"318 - 327"},"PeriodicalIF":2.4,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47750352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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