Pub Date : 2022-05-20DOI: 10.1080/09670262.2022.2066188
Regina Kolzenburg, D. Coaten, F. Ragazzola
Abstract Intertidal macroalgae are exposed to many biotic and abiotic stressors, including significant fluctuations in environmental parameters such as salinity, temperature, pH and solar radiation. This study characterized populations of the intertidal calcifying red alga Corallina officinalis across its geographic distribution in the North-east Atlantic. Processes examined included primary production, respiration, light and dark calcification, photosynthesis-irradiance, and calcification-irradiance evolution. Results confirmed significant differences in the physiology of C. officinalis between latitudes with a clear north-to-south gradient. Compared with central and southern populations of this species, northern populations appeared to be the most robust, showing potential for local physiological adaptation in response to increased variability in environmental factors present within their habitat. Conversely, southern populations displayed a distinct lack of local adaptation compared with northern populations. This is possibly due to southern populations being located within an environment at the upper limit of their stress tolerance, therefore restricting the species’ ability to adapt. As a result, future permanent decline, or even disappearance, of C. officinalis within southern locations of the North-east Atlantic could occur, a process that is likely to be accelerated by predicted future climatic changes. Furthermore, given the essential role these ecosystem engineers play within their habitat, any loss of C. officinalis is also expected to have a strongly negative impact on the surrounding environment. HIGHLIGHTS Decoupled photosynthesis and calcification in Corallina. officinalis show complex relationships, not direct dependencies. Most physiological characteristics in northern C. officinalis populations differ significantly from those in central and southern locations. Species adaptation is predominantly to lower light and temperature conditions.
{"title":"Physiological characterisation of the calcified alga Corallina officinalis (Rhodophyta) from the leading to trailing edge in the Northeast Atlantic","authors":"Regina Kolzenburg, D. Coaten, F. Ragazzola","doi":"10.1080/09670262.2022.2066188","DOIUrl":"https://doi.org/10.1080/09670262.2022.2066188","url":null,"abstract":"Abstract Intertidal macroalgae are exposed to many biotic and abiotic stressors, including significant fluctuations in environmental parameters such as salinity, temperature, pH and solar radiation. This study characterized populations of the intertidal calcifying red alga Corallina officinalis across its geographic distribution in the North-east Atlantic. Processes examined included primary production, respiration, light and dark calcification, photosynthesis-irradiance, and calcification-irradiance evolution. Results confirmed significant differences in the physiology of C. officinalis between latitudes with a clear north-to-south gradient. Compared with central and southern populations of this species, northern populations appeared to be the most robust, showing potential for local physiological adaptation in response to increased variability in environmental factors present within their habitat. Conversely, southern populations displayed a distinct lack of local adaptation compared with northern populations. This is possibly due to southern populations being located within an environment at the upper limit of their stress tolerance, therefore restricting the species’ ability to adapt. As a result, future permanent decline, or even disappearance, of C. officinalis within southern locations of the North-east Atlantic could occur, a process that is likely to be accelerated by predicted future climatic changes. Furthermore, given the essential role these ecosystem engineers play within their habitat, any loss of C. officinalis is also expected to have a strongly negative impact on the surrounding environment. HIGHLIGHTS Decoupled photosynthesis and calcification in Corallina. officinalis show complex relationships, not direct dependencies. Most physiological characteristics in northern C. officinalis populations differ significantly from those in central and southern locations. Species adaptation is predominantly to lower light and temperature conditions.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42518408","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 : 2022-04-13DOI: 10.1080/09670262.2022.2048268
Mary Joy Halog Libatique, Han-Yang Yeh, F. Nan, Meng-Chou Lee
ABSTRACT Algal susceptivity to inorganic arsenate As(V) is linked to the plant nutrient phosphate due to their similar uptake processes. This study determines the response of Sarcodia suae to three phosphate concentrations (1, 10 and 20 mg l–1) when exposed to As(V) (0, 250 µg l–1) for 7 days. The parameters measured include growth, pigments (Chlorophyll a (Chl a), allophycocyanin (APC), phycocyanin (PC), phycoerythrin (PE), total phycobiliproteins (TPBP) and carotenoids), inorganic arsenic (iAs), and total arsenic (TAs) uptake behaviour and bioaccumulation capacity. The growth rate showed significant differences among treatments. Significantly higher levels of pigments including Chl a and carotenoids were observed with an increase in external phosphate concentrations. On the other hand, APC, PC, PE and TPBP showed no significant differences among treatments. The trend of iAs and TAs uptake when phosphate is high suggests competition between phosphate and As(V) as is evident from the reduction of uptake with increased phosphate. The depletion of phosphate and As(V) in the medium also suggests accumulation by the algae. In addition, S. suae was considered an As accumulator but not a hyperaccumulator as defined on its bioaccumulation capacity of 48 and 97 mg kg–1 of iAs and TAs, respectively. Overall, these findings suggest that environmental factors including levels of phosphate have a key role in developing effective As bioremediation in the environment. Highlights Phosphate in Sarcodia suae probably regulates arsenic uptake. Photosynthetic pigments can be linked to competitive mechanisms of As(V). The red alga Sarcodia suae is a candidate for As wastewater treatments by Bioconcentration Factor analysis.
{"title":"Phosphate affects susceptivity of Sarcodia suae to arsenate","authors":"Mary Joy Halog Libatique, Han-Yang Yeh, F. Nan, Meng-Chou Lee","doi":"10.1080/09670262.2022.2048268","DOIUrl":"https://doi.org/10.1080/09670262.2022.2048268","url":null,"abstract":"ABSTRACT Algal susceptivity to inorganic arsenate As(V) is linked to the plant nutrient phosphate due to their similar uptake processes. This study determines the response of Sarcodia suae to three phosphate concentrations (1, 10 and 20 mg l–1) when exposed to As(V) (0, 250 µg l–1) for 7 days. The parameters measured include growth, pigments (Chlorophyll a (Chl a), allophycocyanin (APC), phycocyanin (PC), phycoerythrin (PE), total phycobiliproteins (TPBP) and carotenoids), inorganic arsenic (iAs), and total arsenic (TAs) uptake behaviour and bioaccumulation capacity. The growth rate showed significant differences among treatments. Significantly higher levels of pigments including Chl a and carotenoids were observed with an increase in external phosphate concentrations. On the other hand, APC, PC, PE and TPBP showed no significant differences among treatments. The trend of iAs and TAs uptake when phosphate is high suggests competition between phosphate and As(V) as is evident from the reduction of uptake with increased phosphate. The depletion of phosphate and As(V) in the medium also suggests accumulation by the algae. In addition, S. suae was considered an As accumulator but not a hyperaccumulator as defined on its bioaccumulation capacity of 48 and 97 mg kg–1 of iAs and TAs, respectively. Overall, these findings suggest that environmental factors including levels of phosphate have a key role in developing effective As bioremediation in the environment. Highlights Phosphate in Sarcodia suae probably regulates arsenic uptake. Photosynthetic pigments can be linked to competitive mechanisms of As(V). The red alga Sarcodia suae is a candidate for As wastewater treatments by Bioconcentration Factor analysis.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48772224","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 : 2022-04-04DOI: 10.1080/09670262.2022.2041731
M. M. Barreto Filho, I. L. Bagatini, Pierre M. Durand
Abstract Programmed cell death (PCD) plays a key role in unicellular microalgal ecology. However, the methodologies for detecting PCD are problematic. Clearly, to interpret the empirical data, clarity on how to measure microalgal PCD is essential. Here, we critically review the current measurements of PCD and provide suggestions for future methodological developments and interpretations. We review the traditional measures of PCD and associated cellular responses in microalgae and provide assessments of their frequencies of use and true positive rates. Traditional physiological measurements of photosynthetic activity, change in gene regulation, measurements of reactive oxygen species and terminal deoxynucleotidyl transferase dUTP nick end labelling are highly sensitive assays. They provide important measures of cellular physiological responses but are not unique to PCD. Both caspase-like and metacaspase activity reveal useful information about stress responses and demonstrate high (94% and 100%, respectively) positivity rates, however, they can play a role in cell activities other than death. Furthermore, the controversy surrounding positive caspase assays, even though microalgae encode metacaspases rather than orthologous caspases, is highlighted. DNA laddering had the lowest true positive rate (64%) and was not reported in diatoms while phosphatidylserine externalization was consistently positive in all taxa except dinoflagellates. These data illustrate the limitations of some PCD markers across different taxa. Ultrastructural alterations (transmission electron microscopy) were highly correlated with PCD across all microalgal taxa (true positive rate of 94%) and seem essential for the initial assessments of whether a cell is dying in an organized, ‘programmed’ way. However, in the face of the complexity of PCD phenotypes and the non-specific nature of the methodologies, no single indicator can be used to diagnose PCD. Here, we highlight the importance of employing a time-sensitive multi-assay approach to detect PCD in the eukaryotic microalgae before any ecological or evolutionary interpretations can be made. Highlights Measurements of PCD have different specificities and sensitivities. TEM appears essential as part of an initial investigation. Complementary markers provide information about cell stress and death responses.
{"title":"How shall we measure programmed cell death in eukaryotic microalgae?","authors":"M. M. Barreto Filho, I. L. Bagatini, Pierre M. Durand","doi":"10.1080/09670262.2022.2041731","DOIUrl":"https://doi.org/10.1080/09670262.2022.2041731","url":null,"abstract":"Abstract Programmed cell death (PCD) plays a key role in unicellular microalgal ecology. However, the methodologies for detecting PCD are problematic. Clearly, to interpret the empirical data, clarity on how to measure microalgal PCD is essential. Here, we critically review the current measurements of PCD and provide suggestions for future methodological developments and interpretations. We review the traditional measures of PCD and associated cellular responses in microalgae and provide assessments of their frequencies of use and true positive rates. Traditional physiological measurements of photosynthetic activity, change in gene regulation, measurements of reactive oxygen species and terminal deoxynucleotidyl transferase dUTP nick end labelling are highly sensitive assays. They provide important measures of cellular physiological responses but are not unique to PCD. Both caspase-like and metacaspase activity reveal useful information about stress responses and demonstrate high (94% and 100%, respectively) positivity rates, however, they can play a role in cell activities other than death. Furthermore, the controversy surrounding positive caspase assays, even though microalgae encode metacaspases rather than orthologous caspases, is highlighted. DNA laddering had the lowest true positive rate (64%) and was not reported in diatoms while phosphatidylserine externalization was consistently positive in all taxa except dinoflagellates. These data illustrate the limitations of some PCD markers across different taxa. Ultrastructural alterations (transmission electron microscopy) were highly correlated with PCD across all microalgal taxa (true positive rate of 94%) and seem essential for the initial assessments of whether a cell is dying in an organized, ‘programmed’ way. However, in the face of the complexity of PCD phenotypes and the non-specific nature of the methodologies, no single indicator can be used to diagnose PCD. Here, we highlight the importance of employing a time-sensitive multi-assay approach to detect PCD in the eukaryotic microalgae before any ecological or evolutionary interpretations can be made. Highlights Measurements of PCD have different specificities and sensitivities. TEM appears essential as part of an initial investigation. Complementary markers provide information about cell stress and death responses.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49093490","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}
Abstract The order Oedogoniales comprises three genera, Oedogonium, Oedocladium and Bulbochaete, which were classified based on traditional morphological criteria, and includes more than 600 described species. This group is economically important in astaxanthin production and the energy sector. However, only one mitochondrial genome (mitogenome) has been reported so far. This study determined the mitochondrial genomes of seven Oedogoniales species, including six Oedogonium species and Oedocladium prescottii. Comparative analyses between the newly determined mitogenomes and the previously reported Bulbochaete rectangularis var. hiloensis mitogenome showed that all eight mitogenomes comprised 12 protein-coding genes (PCGs) and two rRNAs; however, the mitogenomes differed in their genome sizes, GC content, tRNAs, non-coding regions and introns. Synteny analysis of the eight mitogenomes revealed a high degree of syntenic conservation in general, with some rearrangements and inversions. The average nucleotide identity (ANI) analysis of the eight mitogenomes indicated Oedogonium dentireticulatum showed high similarity with Oedogonium sp3 (ANI of 96.32%). Most of the PCGs of the eight mitogenomes presented the conventional start codon ATG and stop codon TAR (TAA/TAG/TGA), and the synonymous codon preferences were conserved. Phylogenetic results indicated that Oedogonium was polyphyletic, and species of Oedocladium clustered with Oedogonium, while the position of B. rectangularis var. hiloensis was uncertain for the incongruent phylogenetic results. Statistical analyses of substitution rates demonstrated no significant differences among the three genera, and the dN/dS ratios based on branch model showed that cob, cox1 and nad4 of Oedocladium prescottii and B. rectangularis var. hiloensis were putative fast-evolving genes. These findings suggested that the traditional taxonomy of Oedogoniales did not define natural groups, and that species of Oedocladium and Bulbochaete may have undergone rapid evolution.
{"title":"Mitochondrial genome structure, phylogenetic analyses and substitution rate estimation of the Oedogoniales","authors":"Qian Xiong, Jiaqing Wang, Yuxin Hu, Qinghua Wang, Guoxiang Liu, Zhengyu Hu","doi":"10.1080/09670262.2022.2035825","DOIUrl":"https://doi.org/10.1080/09670262.2022.2035825","url":null,"abstract":"Abstract The order Oedogoniales comprises three genera, Oedogonium, Oedocladium and Bulbochaete, which were classified based on traditional morphological criteria, and includes more than 600 described species. This group is economically important in astaxanthin production and the energy sector. However, only one mitochondrial genome (mitogenome) has been reported so far. This study determined the mitochondrial genomes of seven Oedogoniales species, including six Oedogonium species and Oedocladium prescottii. Comparative analyses between the newly determined mitogenomes and the previously reported Bulbochaete rectangularis var. hiloensis mitogenome showed that all eight mitogenomes comprised 12 protein-coding genes (PCGs) and two rRNAs; however, the mitogenomes differed in their genome sizes, GC content, tRNAs, non-coding regions and introns. Synteny analysis of the eight mitogenomes revealed a high degree of syntenic conservation in general, with some rearrangements and inversions. The average nucleotide identity (ANI) analysis of the eight mitogenomes indicated Oedogonium dentireticulatum showed high similarity with Oedogonium sp3 (ANI of 96.32%). Most of the PCGs of the eight mitogenomes presented the conventional start codon ATG and stop codon TAR (TAA/TAG/TGA), and the synonymous codon preferences were conserved. Phylogenetic results indicated that Oedogonium was polyphyletic, and species of Oedocladium clustered with Oedogonium, while the position of B. rectangularis var. hiloensis was uncertain for the incongruent phylogenetic results. Statistical analyses of substitution rates demonstrated no significant differences among the three genera, and the dN/dS ratios based on branch model showed that cob, cox1 and nad4 of Oedocladium prescottii and B. rectangularis var. hiloensis were putative fast-evolving genes. These findings suggested that the traditional taxonomy of Oedogoniales did not define natural groups, and that species of Oedocladium and Bulbochaete may have undergone rapid evolution.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46571116","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 : 2022-03-28DOI: 10.1080/09670262.2022.2042603
Shin Watanabe, Naoto Mezaki, T. Nakada
Abstract We describe Parietochloris toyamaensis sp. nov. and verify the taxonomic status of P. bilobata (originally described as Neochloris and once combined with Ettlia), using ultrastructural and molecular analyses. P. toyamaensis was isolated from soil collected in Toyama, Japan. It had a parietal chloroplast with pyrenoids that were discontinuously covered with starch segments and penetrated more or less in parallel by thylakoid membranes, and reproduced by forming naked, somewhat dorsoventral, biflagellate zoospores. Two contractile vacuoles were in line lengthwise, located in the median ventral side of the zoospores, as in the type P. alveolaris. The basal apparatus components included a single microtubule in the dexter root. P. toyamaensis was separately resolved from other members of the genus in the 18S rDNA and ITS2 trees. Since the authentic strain ASIB V141 of P. bilobata (stored as Ettlia) has been lost, ASIB V143 was used as a reference in place of it. P. bilobata ASIB V143 was resolved in the ‘Parietochloris sensu stricto’ clade but not ‘Lobosphaera’ clade in the 18S rDNA tree, so taxonomically the combination of N. bilobata with Parietochloris as P. bilobata by Andreyeva was confirmed. In zoospores of the strains of P. bilobata, contractile vacuoles were located in the ventral side, as in P. alveolaris. The taxonomic relationship between P. bilobata and P. grandis, and evaluation of the unique position of contractile vacuoles in dorsoventral zoospores as one of the key characters of Parietochloris were discussed. Highlights Characterization of the species of Parietochloris by using ultrastructural and molecular data. Proposal of Parietochloris toyamaensis sp. nov. Verification of phylogenetic position of Parietochloris bilobata.
{"title":"Ultrastructure and phylogeny of Parietochloris toyamaensis sp. nov. and P. bilobata (Trebouxiophyceae)","authors":"Shin Watanabe, Naoto Mezaki, T. Nakada","doi":"10.1080/09670262.2022.2042603","DOIUrl":"https://doi.org/10.1080/09670262.2022.2042603","url":null,"abstract":"Abstract We describe Parietochloris toyamaensis sp. nov. and verify the taxonomic status of P. bilobata (originally described as Neochloris and once combined with Ettlia), using ultrastructural and molecular analyses. P. toyamaensis was isolated from soil collected in Toyama, Japan. It had a parietal chloroplast with pyrenoids that were discontinuously covered with starch segments and penetrated more or less in parallel by thylakoid membranes, and reproduced by forming naked, somewhat dorsoventral, biflagellate zoospores. Two contractile vacuoles were in line lengthwise, located in the median ventral side of the zoospores, as in the type P. alveolaris. The basal apparatus components included a single microtubule in the dexter root. P. toyamaensis was separately resolved from other members of the genus in the 18S rDNA and ITS2 trees. Since the authentic strain ASIB V141 of P. bilobata (stored as Ettlia) has been lost, ASIB V143 was used as a reference in place of it. P. bilobata ASIB V143 was resolved in the ‘Parietochloris sensu stricto’ clade but not ‘Lobosphaera’ clade in the 18S rDNA tree, so taxonomically the combination of N. bilobata with Parietochloris as P. bilobata by Andreyeva was confirmed. In zoospores of the strains of P. bilobata, contractile vacuoles were located in the ventral side, as in P. alveolaris. The taxonomic relationship between P. bilobata and P. grandis, and evaluation of the unique position of contractile vacuoles in dorsoventral zoospores as one of the key characters of Parietochloris were discussed. Highlights Characterization of the species of Parietochloris by using ultrastructural and molecular data. Proposal of Parietochloris toyamaensis sp. nov. Verification of phylogenetic position of Parietochloris bilobata.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48696980","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 : 2022-03-14DOI: 10.1080/09670262.2022.2031304
E. Gusev, N. Martynenko, P. Kulizin, M. Kulikovskiy
ABSTRACT Molecular data were used to revise the diversity of the genus Cryptomonas in Russia, using samples collected across nine geographic regions within Russia from 2015–2019. Several molecular markers were used: nuclear SSU, LSU and ITS2 rDNA, and plastid psbA. In total, 24 species of the genus Cryptomonas were identified in the country’s fresh waters based on 122 different strains. Six new species were identified and are described here (Cryptomonas matvienkoae sp. nov., C. furtiva sp. nov., C. paludosa sp. nov., C. ursina sp. nov., C. kisselevii sp. nov. and C. meshchorana sp. nov.), and three taxa are emended (Cryptomonas skujae, C. platyuris and C. obovata). These new and emended species group in clades with the previously described species or represent new lineages on the phylogenetic tree. Seven morphospecies, previously reported in Russia, are confirmed by molecular methods, and two unidentified taxa are also reported. HIGHLIGHTS Molecular investigations of the genus Cryptomonas in Russia revealed 24 species. Descriptions of three species were emended. Six species new to science were described.
{"title":"Molecular diversity of the genus Cryptomonas (Cryptophyceae) in Russia","authors":"E. Gusev, N. Martynenko, P. Kulizin, M. Kulikovskiy","doi":"10.1080/09670262.2022.2031304","DOIUrl":"https://doi.org/10.1080/09670262.2022.2031304","url":null,"abstract":"ABSTRACT Molecular data were used to revise the diversity of the genus Cryptomonas in Russia, using samples collected across nine geographic regions within Russia from 2015–2019. Several molecular markers were used: nuclear SSU, LSU and ITS2 rDNA, and plastid psbA. In total, 24 species of the genus Cryptomonas were identified in the country’s fresh waters based on 122 different strains. Six new species were identified and are described here (Cryptomonas matvienkoae sp. nov., C. furtiva sp. nov., C. paludosa sp. nov., C. ursina sp. nov., C. kisselevii sp. nov. and C. meshchorana sp. nov.), and three taxa are emended (Cryptomonas skujae, C. platyuris and C. obovata). These new and emended species group in clades with the previously described species or represent new lineages on the phylogenetic tree. Seven morphospecies, previously reported in Russia, are confirmed by molecular methods, and two unidentified taxa are also reported. HIGHLIGHTS Molecular investigations of the genus Cryptomonas in Russia revealed 24 species. Descriptions of three species were emended. Six species new to science were described.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46637575","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 : 2022-03-09DOI: 10.1080/09670262.2022.2029950
C. Rodríguez-Prieto, Y. Chuang, Showe-Mei Lin
ABSTRACT Among the eight species of Yonagunia described in the Indo-Pacific region, five species have been reported from Taiwan. In this study, we re-examined additional herbarium specimens which were morphologically similar to the other Taiwanese species of Yonagunia. Two new species of Yonagunia (Y. robusta sp. nov. and Y. stipitata sp. nov.) were identified based on rbcL sequence analyses, and their vegetative and reproductive structures were documented in detail. Yonagunia robusta is the largest species (up to 13 cm high) found in Taiwan and superficially resembles a previously described species, Y. palmata from northern Taiwan, but the thallus size is much larger and the branches are coarser in Y. robusta. Young plants of Y. stipitata may be confused with Y. maillardii, a species widely distributed in the Indo-Pacific, but the thallus branches are much thinner and numerous reproductive branchlets are formed in clusters in fertile Y. stipitata. Yonagunia robusta is widely distributed from northern to south-eastern Taiwan, whereas Y. stipitata is restricted to Orchid Island, a remote small island off the south-east of Taiwan. The species diversity (seven out of 10 described species) of Yonagunia is high in Taiwan and it is speculated that some more cryptic species will be found from the Indo-Pacific by using a combination of DNA sequence data and morphological observations. HIGHLIGHTS Ten species of Yonagunia have been described from the Indo-Pacific. Seven out of 10 species of Yonagunia are found in Taiwan. Cryptic species of Yonagunia will be found in the Indo-Pacific.
{"title":"Systematic revision of the red algal genus Yonagunia (Halymeniaceae, Rhodophyta) from Taiwan, including the description of two new species","authors":"C. Rodríguez-Prieto, Y. Chuang, Showe-Mei Lin","doi":"10.1080/09670262.2022.2029950","DOIUrl":"https://doi.org/10.1080/09670262.2022.2029950","url":null,"abstract":"ABSTRACT Among the eight species of Yonagunia described in the Indo-Pacific region, five species have been reported from Taiwan. In this study, we re-examined additional herbarium specimens which were morphologically similar to the other Taiwanese species of Yonagunia. Two new species of Yonagunia (Y. robusta sp. nov. and Y. stipitata sp. nov.) were identified based on rbcL sequence analyses, and their vegetative and reproductive structures were documented in detail. Yonagunia robusta is the largest species (up to 13 cm high) found in Taiwan and superficially resembles a previously described species, Y. palmata from northern Taiwan, but the thallus size is much larger and the branches are coarser in Y. robusta. Young plants of Y. stipitata may be confused with Y. maillardii, a species widely distributed in the Indo-Pacific, but the thallus branches are much thinner and numerous reproductive branchlets are formed in clusters in fertile Y. stipitata. Yonagunia robusta is widely distributed from northern to south-eastern Taiwan, whereas Y. stipitata is restricted to Orchid Island, a remote small island off the south-east of Taiwan. The species diversity (seven out of 10 described species) of Yonagunia is high in Taiwan and it is speculated that some more cryptic species will be found from the Indo-Pacific by using a combination of DNA sequence data and morphological observations. HIGHLIGHTS Ten species of Yonagunia have been described from the Indo-Pacific. Seven out of 10 species of Yonagunia are found in Taiwan. Cryptic species of Yonagunia will be found in the Indo-Pacific.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48277349","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 : 2022-03-07DOI: 10.1080/09670262.2021.2007543
L. Ladah, J. A. Zertuche‐González
ABSTRACT The Pacific coast of the Baja California peninsula (Mexico) is a unique biogeographic transition zone, where many kelp species encounter their southern subtropical limits and have experienced a range contraction in the northern hemisphere. Using reciprocal transplant experiments with giant kelp populations from their southern limit and a northern temperate site on the Baja California peninsula, we hypothesized that juveniles from the southern site would grow longer, have more fronds (an individual stipe with its blades), and have higher photosynthetic efficiency (α) and blade tissue nitrogen, especially under warmer nitrate-limited field conditions experienced in their habitat. At the southern-limit transplant site, local juveniles had more fronds compared with those from the north after 90 days in field conditions (warm waters). At the northern transplant site, blade tissue nitrogen of juveniles from both populations was low after 23 days in field conditions (not significantly different during a warm water period), however, after a further 56 day cooling period and shortly after a strong upwelling event, juveniles from the southern population had greater blade tissue nitrogen concentrations than those from the north, which showed little change. Respiration and a were both greater at higher temperatures in juveniles from the southern population, and this pattern was maintained under warm water field conditions. These physiological differences in conspecific juveniles from different populations may be driven by population-level adaptation to frequently occurring thermal and nutrient stress in southern Baja California, which is the southern distribution limit for giant kelp. Further exploration of population level differences in ecophysiology should be applied to kelp forest restoration efforts as oceans warm.
{"title":"Local adaptation of juvenile giant kelp, Macrocystis pyrifera, from their southern limit in the northern hemisphere explored using reciprocal transplantation","authors":"L. Ladah, J. A. Zertuche‐González","doi":"10.1080/09670262.2021.2007543","DOIUrl":"https://doi.org/10.1080/09670262.2021.2007543","url":null,"abstract":"ABSTRACT The Pacific coast of the Baja California peninsula (Mexico) is a unique biogeographic transition zone, where many kelp species encounter their southern subtropical limits and have experienced a range contraction in the northern hemisphere. Using reciprocal transplant experiments with giant kelp populations from their southern limit and a northern temperate site on the Baja California peninsula, we hypothesized that juveniles from the southern site would grow longer, have more fronds (an individual stipe with its blades), and have higher photosynthetic efficiency (α) and blade tissue nitrogen, especially under warmer nitrate-limited field conditions experienced in their habitat. At the southern-limit transplant site, local juveniles had more fronds compared with those from the north after 90 days in field conditions (warm waters). At the northern transplant site, blade tissue nitrogen of juveniles from both populations was low after 23 days in field conditions (not significantly different during a warm water period), however, after a further 56 day cooling period and shortly after a strong upwelling event, juveniles from the southern population had greater blade tissue nitrogen concentrations than those from the north, which showed little change. Respiration and a were both greater at higher temperatures in juveniles from the southern population, and this pattern was maintained under warm water field conditions. These physiological differences in conspecific juveniles from different populations may be driven by population-level adaptation to frequently occurring thermal and nutrient stress in southern Baja California, which is the southern distribution limit for giant kelp. Further exploration of population level differences in ecophysiology should be applied to kelp forest restoration efforts as oceans warm.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46029353","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 : 2022-03-04DOI: 10.1080/09670262.2022.2029949
D. Grzebyk, V. Pasqualini, M. Garrido, Y. Quilichini, Clément Pereto, P. Cecchi
ABSTRACT Among the marine planktonic diatoms, Chaetoceros is among the most species-rich genera, and many Chaetoceros species are considered important primary producers. However, little is known about the ecology and distribution of the few small solitary species within this genus, including Chaetoceros tenuissimus. This article describes a minute Chaetoceros strain, identified as C. tenuissimus (named CT16ED) that was isolated at a coastal lagoon in Corsica Island, Western Mediterranean. The strain was characterized by light microscopy and scanning and transmission electron microscopy, with a specific focus on the fine structure and construction of setae and its behaviour in culture. The CT16ED strain was compared with other strains we isolated from the species type locality (Ostend Harbour, North Sea) by sequencing a fragment of the nuclear ribosomal DNA (rDNA) spanning from the 18S rDNA to the D3 region of the 28S rDNA, and the plastid rbcL gene that codes the large RuBisCO subunit. Based on the literature and the available sequence data, the analysed strains were similar to C. tenuissimus but the phylogenetic analysis indicated a C. tenuissimus species complex that contained several clades, therefore the current taxonomic status of C. tenuissimus is discussed. The comparison with the available rDNA and rbcL sequencing data of strains assigned to species considered as synonyms of C. tenuissimus, including Chaetoceros simplex var. calcitrans, Chaetoceros calcitrans and Chaetoceros calcitrans f. pumilus, suggested that these taxa are paraphyletic within the genus Chaetoceros.
{"title":"Insight into the morphology and genetic diversity of the Chaetoceros tenuissimus (Bacillariophyta) species complex","authors":"D. Grzebyk, V. Pasqualini, M. Garrido, Y. Quilichini, Clément Pereto, P. Cecchi","doi":"10.1080/09670262.2022.2029949","DOIUrl":"https://doi.org/10.1080/09670262.2022.2029949","url":null,"abstract":"ABSTRACT Among the marine planktonic diatoms, Chaetoceros is among the most species-rich genera, and many Chaetoceros species are considered important primary producers. However, little is known about the ecology and distribution of the few small solitary species within this genus, including Chaetoceros tenuissimus. This article describes a minute Chaetoceros strain, identified as C. tenuissimus (named CT16ED) that was isolated at a coastal lagoon in Corsica Island, Western Mediterranean. The strain was characterized by light microscopy and scanning and transmission electron microscopy, with a specific focus on the fine structure and construction of setae and its behaviour in culture. The CT16ED strain was compared with other strains we isolated from the species type locality (Ostend Harbour, North Sea) by sequencing a fragment of the nuclear ribosomal DNA (rDNA) spanning from the 18S rDNA to the D3 region of the 28S rDNA, and the plastid rbcL gene that codes the large RuBisCO subunit. Based on the literature and the available sequence data, the analysed strains were similar to C. tenuissimus but the phylogenetic analysis indicated a C. tenuissimus species complex that contained several clades, therefore the current taxonomic status of C. tenuissimus is discussed. The comparison with the available rDNA and rbcL sequencing data of strains assigned to species considered as synonyms of C. tenuissimus, including Chaetoceros simplex var. calcitrans, Chaetoceros calcitrans and Chaetoceros calcitrans f. pumilus, suggested that these taxa are paraphyletic within the genus Chaetoceros.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49008325","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 : 2022-02-21DOI: 10.1080/09670262.2022.2029948
Biaobiao Niu, Yaqiong Guo, N. Lundholm, Yang Li
ABSTRACT Thalassiosira and related taxa i.e. the taxa within Thalassiosirales are among the most abundant and widespread diatoms. The vast majority have one marginal rimoportula, but very few always have two. The knowledge on Thalassiosiroid taxa in Chinese waters is restricted, and to explore the diversity, monoclonal strains were established from southern Chinese coastal waters. Morphological data were based on light and scanning electron microscopy. The D1‒D3 region of the ribosomal large subunit (LSU) and the small subunit (SSU) encoding genes were amplified to address phylogenetic relationships. Based on a combination of morphological characters and molecular analyses, two new species with two marginal rimoportulae were described, Planktoniella pulchra sp. nov. and Thalassiosira tridens sp. nov. Planktoniella pulchra is furthermore characterized by one regular ring of marginal fultoportulae between the valve face and the mantle, as well as dense ribs on the mantle. A narrow circular extension of mucilaginous material surrounds the girdle. In phylogenetic analyses, it clustered within the Planktoniella group. Thalassiosira tridens is unique in having a pronounced external tube of the central fultoportula, as well as long external tubes of the two marginal rimoportulae. Two irregular rings formed by the marginal fultoportulae are present on the mantle, and their external extensions are either open tubes or closed spines. In the SSU and LSU phylogenetic analyses, both taxa constituted their own monophyletic lineage and were well differentiated from allied species. Thalassiosiroid taxa with two marginal rimoportulae were phylogenetically closely related, but did not make up a monophyletic lineage.
{"title":"Morphology and phylogeny of two new Thalassiosiroid taxa (Bacillariophyceae), with two marginal rimoportulae","authors":"Biaobiao Niu, Yaqiong Guo, N. Lundholm, Yang Li","doi":"10.1080/09670262.2022.2029948","DOIUrl":"https://doi.org/10.1080/09670262.2022.2029948","url":null,"abstract":"ABSTRACT Thalassiosira and related taxa i.e. the taxa within Thalassiosirales are among the most abundant and widespread diatoms. The vast majority have one marginal rimoportula, but very few always have two. The knowledge on Thalassiosiroid taxa in Chinese waters is restricted, and to explore the diversity, monoclonal strains were established from southern Chinese coastal waters. Morphological data were based on light and scanning electron microscopy. The D1‒D3 region of the ribosomal large subunit (LSU) and the small subunit (SSU) encoding genes were amplified to address phylogenetic relationships. Based on a combination of morphological characters and molecular analyses, two new species with two marginal rimoportulae were described, Planktoniella pulchra sp. nov. and Thalassiosira tridens sp. nov. Planktoniella pulchra is furthermore characterized by one regular ring of marginal fultoportulae between the valve face and the mantle, as well as dense ribs on the mantle. A narrow circular extension of mucilaginous material surrounds the girdle. In phylogenetic analyses, it clustered within the Planktoniella group. Thalassiosira tridens is unique in having a pronounced external tube of the central fultoportula, as well as long external tubes of the two marginal rimoportulae. Two irregular rings formed by the marginal fultoportulae are present on the mantle, and their external extensions are either open tubes or closed spines. In the SSU and LSU phylogenetic analyses, both taxa constituted their own monophyletic lineage and were well differentiated from allied species. Thalassiosiroid taxa with two marginal rimoportulae were phylogenetically closely related, but did not make up a monophyletic lineage.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41984241","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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