Pub Date : 2021-06-16DOI: 10.1080/09670262.2021.1888390
Neha Wadmare, A. Baghela, J. Kociolek, B. Karthick
ABSTRACT Stauroneis Ehrenberg is a species-rich genus that is common and widespread with some variation in frustule morphology. Recently, studies have explored the molecular diversity of the Stauroneis from the temperate region, but there are no molecular data for tropical species. In the present study, four species of Stauroneis were investigated using morphological and molecular data. Morphological characters were analysed using light microscopy (LM) and scanning electron microscopy (SEM), and the features of each taxon were compared with similar species within the genus. For the molecular analyses, Stauroneis strains were isolated, cultured, DNA was extracted, and sequences from rbcL and 18S genes were analysed to determine phylogenetic relationships. Our analysis describes three new species and records one previously known species. The new species are: (1) Stauroneis lateritica Wadmare, Kociolek & B.Karthick, characterized by small frustules with elliptical lanceolate valves and short subrostrate apices, broad central bow-tie shaped stauros, and few moderate striae centrally becoming strongly radiate towards the poles; (2) Stauroneis sholaii Wadmare, Kociolek & B.Karthick, which has broad lanceolate valves with short rectangular stauros and radiate striae; and (3) Stauroneis bartii Wadmare, Kociolek & B.Karthick, which has large, lanceolate valves with rounded apices, a stauros with 4–7 shortened striae and radiate striae. Ultrastructure and molecular data from India for the previously known, widespread species Stauroneis gracilis Ehrenberg are presented. The combined morphological and molecular approach supports recognition of S. lateritica, S. sholaii and S. bartii as new species. This study is the first-ever attempt at molecular species discovery of diatoms from the Indian subcontinent.
{"title":"Description and phylogenetic position of three new species of Stauroneis Ehrenberg (Bacillariophyceae: Stauroneidaceae) from the Indian Subcontinent","authors":"Neha Wadmare, A. Baghela, J. Kociolek, B. Karthick","doi":"10.1080/09670262.2021.1888390","DOIUrl":"https://doi.org/10.1080/09670262.2021.1888390","url":null,"abstract":"ABSTRACT Stauroneis Ehrenberg is a species-rich genus that is common and widespread with some variation in frustule morphology. Recently, studies have explored the molecular diversity of the Stauroneis from the temperate region, but there are no molecular data for tropical species. In the present study, four species of Stauroneis were investigated using morphological and molecular data. Morphological characters were analysed using light microscopy (LM) and scanning electron microscopy (SEM), and the features of each taxon were compared with similar species within the genus. For the molecular analyses, Stauroneis strains were isolated, cultured, DNA was extracted, and sequences from rbcL and 18S genes were analysed to determine phylogenetic relationships. Our analysis describes three new species and records one previously known species. The new species are: (1) Stauroneis lateritica Wadmare, Kociolek & B.Karthick, characterized by small frustules with elliptical lanceolate valves and short subrostrate apices, broad central bow-tie shaped stauros, and few moderate striae centrally becoming strongly radiate towards the poles; (2) Stauroneis sholaii Wadmare, Kociolek & B.Karthick, which has broad lanceolate valves with short rectangular stauros and radiate striae; and (3) Stauroneis bartii Wadmare, Kociolek & B.Karthick, which has large, lanceolate valves with rounded apices, a stauros with 4–7 shortened striae and radiate striae. Ultrastructure and molecular data from India for the previously known, widespread species Stauroneis gracilis Ehrenberg are presented. The combined morphological and molecular approach supports recognition of S. lateritica, S. sholaii and S. bartii as new species. This study is the first-ever attempt at molecular species discovery of diatoms from the Indian subcontinent.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2021-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09670262.2021.1888390","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46079488","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 : 2021-06-16DOI: 10.1080/09670262.2021.1880643
V. Peña, D. Bélanger, P. Gagnon, J. Richards, L. le Gall, Jeffery R. Hughey, G. Saunders, S. Lindstrom, E. Rinde, V. Husa, H. Christie, S. Fredriksen, J. Hall‐Spencer, R. Steneck, Kathryn M. Schoenrock, J. Gitmark, E. S. Grefsrud, M. A. Anglès d’Auriac, E. Legrand, J. Grall, T. Mumford, N. Kamenos, P. Gabrielson
ABSTRACT Coralline red algae in the non-geniculate genera Clathromorphum, Phymatolithon and Lithothamnion are important benthic ecosystem engineers in the photic zone of the Arctic and Subarctic. In these regions, the systematics and biogeography of Clathromorphum and Phymatolithon have mostly been resolved whereas Lithothamnion has not, until now. Seventy-three specific and infraspecific names were given to Arctic and Subarctic Lithothamnion specimens in the late 19th and early 20th century by Frans R. Kjellman and Mikael H. Foslie. DNA sequences from 36 type specimens, five historical specimens, and an extensive sampling of recent collections resulted in the recognition of four Arctic and Subarctic Lithothamnion species, L. glaciale, L. lemoineae, L. soriferum and L. tophiforme. Three genes were sequenced, two plastid-encoded, rbcL and psbA, and the mitochondrial encoded COI-5P; rbcL and COI-5P segregated L. glaciale from L. tophiforme but psbA did not. Partial rbcL sequences obtained from type collections enabled us to correctly apply the earliest available names and to correctly place the remainder in synonymy. We were unable to sequence another 22 type specimens, but all of these are more recent names than those that are now applied. It is difficult to identify these species solely on morpho-anatomy as they can all occur as encrusting corallines or as maerl (rhodoliths). We demonstrate the importance of sequencing historical type specimens by showing that the recently proposed North-east Atlantic L. erinaceum is a synonym of one of the earliest published Arctic species of Lithothamnion, L. soriferum, itself incorrectly placed in synonymy under L. tophiforme based on morpho-anatomy. Based on sequenced specimens, we update the distributions and ecology of these species.
珊瑚红藻属(Clathromorphum、Phymatolithon和Lithothamnion)是北极和亚北极光带重要的底栖生态系统工程师。在这些地区，毛藻门(Clathromorphum)和藻石门(Phymatolithon)的系统学和生物地理学已基本解决，而石石门(Lithothamnion)至今尚未解决。19世纪末和20世纪初，Frans R. Kjellman和Mikael H. Foslie给北极和亚北极石岩鼠标本起了73个特定的和非特定的名字。通过对36个模式标本、5个历史标本和最近收集的大量标本进行DNA序列分析，鉴定出4个北极和亚北极石岩属物种:L. glaciale、L. lemoineae、L. soriferum和L. tophiforme。三个基因测序，两个质体编码，rbcL和psbA，线粒体编码COI-5P;rbcL和COI-5P对L. glaciale和L. tophiforme有分离作用，而psbA没有。从类型集合中获得的部分rbcL序列使我们能够正确地应用最早的可用名称，并将其余部分正确地放置在同义词中。我们无法对另外22个模式标本进行测序，但所有这些都是比现在使用的名称更近的名称。仅从形态解剖学上识别这些物种是困难的，因为它们都可能以嵌壳珊瑚状或珊瑚状(菱形)的形式出现。我们通过展示最近提出的东北大西洋L. erinaceum是最早发表的Lithothamnion的北极物种之一L. soriferum的同义词，证明了历史模式标本测序的重要性，L. soriferum本身基于形态解剖学被错误地置于L. tophiforme的同义词下。根据测序标本，更新了这些物种的分布和生态。
{"title":"Lithothamnion (Hapalidiales, Rhodophyta) in the changing Arctic and Subarctic: DNA sequencing of type and recent specimens provides a systematics foundation*","authors":"V. Peña, D. Bélanger, P. Gagnon, J. Richards, L. le Gall, Jeffery R. Hughey, G. Saunders, S. Lindstrom, E. Rinde, V. Husa, H. Christie, S. Fredriksen, J. Hall‐Spencer, R. Steneck, Kathryn M. Schoenrock, J. Gitmark, E. S. Grefsrud, M. A. Anglès d’Auriac, E. Legrand, J. Grall, T. Mumford, N. Kamenos, P. Gabrielson","doi":"10.1080/09670262.2021.1880643","DOIUrl":"https://doi.org/10.1080/09670262.2021.1880643","url":null,"abstract":"ABSTRACT Coralline red algae in the non-geniculate genera Clathromorphum, Phymatolithon and Lithothamnion are important benthic ecosystem engineers in the photic zone of the Arctic and Subarctic. In these regions, the systematics and biogeography of Clathromorphum and Phymatolithon have mostly been resolved whereas Lithothamnion has not, until now. Seventy-three specific and infraspecific names were given to Arctic and Subarctic Lithothamnion specimens in the late 19th and early 20th century by Frans R. Kjellman and Mikael H. Foslie. DNA sequences from 36 type specimens, five historical specimens, and an extensive sampling of recent collections resulted in the recognition of four Arctic and Subarctic Lithothamnion species, L. glaciale, L. lemoineae, L. soriferum and L. tophiforme. Three genes were sequenced, two plastid-encoded, rbcL and psbA, and the mitochondrial encoded COI-5P; rbcL and COI-5P segregated L. glaciale from L. tophiforme but psbA did not. Partial rbcL sequences obtained from type collections enabled us to correctly apply the earliest available names and to correctly place the remainder in synonymy. We were unable to sequence another 22 type specimens, but all of these are more recent names than those that are now applied. It is difficult to identify these species solely on morpho-anatomy as they can all occur as encrusting corallines or as maerl (rhodoliths). We demonstrate the importance of sequencing historical type specimens by showing that the recently proposed North-east Atlantic L. erinaceum is a synonym of one of the earliest published Arctic species of Lithothamnion, L. soriferum, itself incorrectly placed in synonymy under L. tophiforme based on morpho-anatomy. Based on sequenced specimens, we update the distributions and ecology of these species.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2021-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09670262.2021.1880643","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48445350","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 : 2021-06-08DOI: 10.1080/09670262.2021.1914862
Jeffery R. Hughey, P. Gabrielson, C. Maggs, F. Mineur
ABSTRACT Species of Ulva Linnaeus are nearly impossible to identify using morpho-anatomy due to their simple thallus structure and phenotypic plasticity. The current solution to this problem is to sequence DNA from field-collected specimens and match these sequences to those available in public DNA databases. However, because type specimens of many species have not been sequenced, the accuracy of these identifications is highly doubtful. Ulva rigida C.Agardh is reported to be one of the most widespread and ecologically important Ulva species, but these records are based on either morpho-anatomy or, more recently, on DNA sequences. High-throughput sequencing (HTS) was performed on the lectotype specimen of U. rigida from Cádiz, Spain to determine the correct application of the name. The analysis yielded its complete plastid genome. rbcL, tufA and ITS sequences from the lectotype specimen differed at the species level from all U. rigida sequences deposited in public databases. Instead, the lectotype sequences of U. rigida were identical or very similar to sequences identified as U. rotundata Bliding (referred to by some as U. pseudorotundata Cormaci, G.Furnari & Alongi) from Ireland and Portugal, but not to the holotype of U. rotundata from Italy, which was identical to U. lactuca L. HTS of the lectotype of U. lacinulata (Kützing) Wittrock from Lesina, Croatia, a species morphologically similar to U. rigida with macroscopic marginal teeth, also yielded a complete plastid genome, with sequences identical or highly similar to GenBank U. armoricana Dion, Reviers & Coat, U. ‘laetevirens’, U. ‘rigida’ and U. scandinavica Bliding. Since U. lacinulata is the oldest validly published name, it is the correct one to apply to the globally distributed species that was previously but incorrectly known as U. rigida. Based on this genetic evidence, U. rigida is restricted to European waters and confirmed by DNA sequences from Ireland, Portugal and Spain. This analysis shows that many barcode species identifications and taxonomic conclusions in the genus Ulva are incorrect. Highlights Ulva rigida was misapplied and is restricted to Atlantic Europe. Ulva lacinulata is the dentate species of Ulva distributed worldwide. Ulva rotundata is a heterotypic synonym of U. lactuca.
{"title":"Genomic analysis of the lectotype specimens of European Ulva rigida and Ulva lacinulata (Ulvaceae, Chlorophyta) reveals the ongoing misapplication of names","authors":"Jeffery R. Hughey, P. Gabrielson, C. Maggs, F. Mineur","doi":"10.1080/09670262.2021.1914862","DOIUrl":"https://doi.org/10.1080/09670262.2021.1914862","url":null,"abstract":"ABSTRACT Species of Ulva Linnaeus are nearly impossible to identify using morpho-anatomy due to their simple thallus structure and phenotypic plasticity. The current solution to this problem is to sequence DNA from field-collected specimens and match these sequences to those available in public DNA databases. However, because type specimens of many species have not been sequenced, the accuracy of these identifications is highly doubtful. Ulva rigida C.Agardh is reported to be one of the most widespread and ecologically important Ulva species, but these records are based on either morpho-anatomy or, more recently, on DNA sequences. High-throughput sequencing (HTS) was performed on the lectotype specimen of U. rigida from Cádiz, Spain to determine the correct application of the name. The analysis yielded its complete plastid genome. rbcL, tufA and ITS sequences from the lectotype specimen differed at the species level from all U. rigida sequences deposited in public databases. Instead, the lectotype sequences of U. rigida were identical or very similar to sequences identified as U. rotundata Bliding (referred to by some as U. pseudorotundata Cormaci, G.Furnari & Alongi) from Ireland and Portugal, but not to the holotype of U. rotundata from Italy, which was identical to U. lactuca L. HTS of the lectotype of U. lacinulata (Kützing) Wittrock from Lesina, Croatia, a species morphologically similar to U. rigida with macroscopic marginal teeth, also yielded a complete plastid genome, with sequences identical or highly similar to GenBank U. armoricana Dion, Reviers & Coat, U. ‘laetevirens’, U. ‘rigida’ and U. scandinavica Bliding. Since U. lacinulata is the oldest validly published name, it is the correct one to apply to the globally distributed species that was previously but incorrectly known as U. rigida. Based on this genetic evidence, U. rigida is restricted to European waters and confirmed by DNA sequences from Ireland, Portugal and Spain. This analysis shows that many barcode species identifications and taxonomic conclusions in the genus Ulva are incorrect. Highlights Ulva rigida was misapplied and is restricted to Atlantic Europe. Ulva lacinulata is the dentate species of Ulva distributed worldwide. Ulva rotundata is a heterotypic synonym of U. lactuca.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09670262.2021.1914862","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48831086","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 : 2021-06-08DOI: 10.1080/09670262.2021.1892196
M. Pusztai, P. Škaloud
ABSTRACT Until recently, there was no agreement on species delimitation within the morphologically similar chrysophycean genera Uroglena, Uroglenopsis and Urostipulosphaera. In this study, we aimed at a modern taxonomic revision based on the combination of morphological characters (ultrastructure of cysts, cell and colony features) and a multigene phylogeny (SSU, ITS rDNA and rbcL sequences), with ecology taken into account. Of more than 650 explored localities, only approximately one in 10 hosted a viable and detectable population of these colonial chrysophytes at the time of sampling. We established and examined 189 short-term cultures along with single colony isolates, derived mostly from blooming or encysting populations. We obtained the cyst morphology for four species and two lineages of Uroglena, two species of Uroglenopsis, and four species of Urostipulosphaera. A total of 12 resolved lineages could be attributed to previously described species or new species (Uroglena imitata sp. nov., Urostipulosphaera granulata sp. nov.). Based on our molecular analyses and morphological observations, we assign all the previously described Uroglena-like taxa to newly recognized genera and propose a key to identification. Consequently, Uroglena now includes 16 species and two varieties, Uroglenopsis contains four species and Urostipulosphaera encompasses nine species. Within Uroglena and Urostipulosphaera, species are defined by the ultrastructure of their cysts. On the contrary, as Uroglenopsis has simple cysts, species are defined by cell and colony characteristics.
{"title":"Species delimitation within the colonial flagellates Uroglena, Uroglenopsis and Urostipulosphaera (Chrysophyceae)","authors":"M. Pusztai, P. Škaloud","doi":"10.1080/09670262.2021.1892196","DOIUrl":"https://doi.org/10.1080/09670262.2021.1892196","url":null,"abstract":"ABSTRACT Until recently, there was no agreement on species delimitation within the morphologically similar chrysophycean genera Uroglena, Uroglenopsis and Urostipulosphaera. In this study, we aimed at a modern taxonomic revision based on the combination of morphological characters (ultrastructure of cysts, cell and colony features) and a multigene phylogeny (SSU, ITS rDNA and rbcL sequences), with ecology taken into account. Of more than 650 explored localities, only approximately one in 10 hosted a viable and detectable population of these colonial chrysophytes at the time of sampling. We established and examined 189 short-term cultures along with single colony isolates, derived mostly from blooming or encysting populations. We obtained the cyst morphology for four species and two lineages of Uroglena, two species of Uroglenopsis, and four species of Urostipulosphaera. A total of 12 resolved lineages could be attributed to previously described species or new species (Uroglena imitata sp. nov., Urostipulosphaera granulata sp. nov.). Based on our molecular analyses and morphological observations, we assign all the previously described Uroglena-like taxa to newly recognized genera and propose a key to identification. Consequently, Uroglena now includes 16 species and two varieties, Uroglenopsis contains four species and Urostipulosphaera encompasses nine species. Within Uroglena and Urostipulosphaera, species are defined by the ultrastructure of their cysts. On the contrary, as Uroglenopsis has simple cysts, species are defined by cell and colony characteristics.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09670262.2021.1892196","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44389514","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 : 2021-06-02DOI: 10.1080/09670262.2021.1914861
Nagore Sampedro, Albert Reñé, Jislene B. Matos, J. Fortuño, E. Garcés
ABSTRACT Many dinoflagellate groups have been overlooked because of their small size compared with their larger counterparts; consequently, little is known about their diversity, distribution, and contribution to the planktonic community. Ansanella is a recently described genus of small marine planktonic dinoflagellates belonging to the order Suessiales. In this study, morphological observations together with molecular SSU and LSU rDNA analyses of clonal strains from the Catalan coast (NW Mediterranean Sea) allowed the identification of A. cf. natalensis and a newly reported species, Ansanella catalana. The cells of A. catalana are oval and 9.6–15.5 μm long; the cell surface is covered with amphiesmal vesicles arranged in 10–13 latitudinal rows; the episome has an apical furrow complex with a single elongated apical vesicle; a type E eyespot is also present. This newly identified species can be distinguished from congeneric species by morphological details of the cell surface, the presence of mucocysts and an extrusome type not previously reported in dinoflagellates. The characterization of this structure could provide insights into extrusome evolution in dinoflagellates. Metabarcoding analysis of plankton and sediment samples from the Catalan coast revealed a wide distribution of Ansanella and the remarkable contribution of this genus to the dinoflagellate communities from three different coastal habitats. Highlights Members of Ansanella genus are widespread along the Catalan coast. A new species of the genus Ansanella (Dinophyceae) is described. A new type of extrusome was observed.
{"title":"Detection of the widespread presence of the genus Ansanella along the Catalan coast (NW Mediterranean Sea) and the description of Ansanella catalana sp. nov. (Dinophyceae)","authors":"Nagore Sampedro, Albert Reñé, Jislene B. Matos, J. Fortuño, E. Garcés","doi":"10.1080/09670262.2021.1914861","DOIUrl":"https://doi.org/10.1080/09670262.2021.1914861","url":null,"abstract":"ABSTRACT Many dinoflagellate groups have been overlooked because of their small size compared with their larger counterparts; consequently, little is known about their diversity, distribution, and contribution to the planktonic community. Ansanella is a recently described genus of small marine planktonic dinoflagellates belonging to the order Suessiales. In this study, morphological observations together with molecular SSU and LSU rDNA analyses of clonal strains from the Catalan coast (NW Mediterranean Sea) allowed the identification of A. cf. natalensis and a newly reported species, Ansanella catalana. The cells of A. catalana are oval and 9.6–15.5 μm long; the cell surface is covered with amphiesmal vesicles arranged in 10–13 latitudinal rows; the episome has an apical furrow complex with a single elongated apical vesicle; a type E eyespot is also present. This newly identified species can be distinguished from congeneric species by morphological details of the cell surface, the presence of mucocysts and an extrusome type not previously reported in dinoflagellates. The characterization of this structure could provide insights into extrusome evolution in dinoflagellates. Metabarcoding analysis of plankton and sediment samples from the Catalan coast revealed a wide distribution of Ansanella and the remarkable contribution of this genus to the dinoflagellate communities from three different coastal habitats. Highlights Members of Ansanella genus are widespread along the Catalan coast. A new species of the genus Ansanella (Dinophyceae) is described. A new type of extrusome was observed.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2021-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09670262.2021.1914861","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42412837","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 : 2021-05-25DOI: 10.1080/09670262.2021.1914860
Olga Carnicer, A. Irwin, Z. Finkel
ABSTRACT Dinoflagellates are amongst the most abundant and diverse groups of plankton in surface waters and contribute to food web productivity and C:N:P biogeochemistry. Here we analyse the C:N:P of marine, autotrophic, planktonic dinoflagellates compiled from culture data from the scientific literature and test if dinoflagellate C:N:P differs from the Redfield ratio, and whether variability in C:N:P is associated with three traits: cell size, wall structure and toxin production. We find the average C:N:P of dinoflagellates is 90:12:1; higher in C:N, and lower in C:P and N:P than the canonical Redfield ratio. In aggregate the three traits examined here account for between 20–31% while taxonomic order accounts for between 37–38% of the variance in C:N:P. Smaller-sized and thecate taxa are higher in C:N, C:P and N:P than larger-size and athecate taxa. Species known to be able to produce C-rich toxins tend to be higher in C:P and N:P while species known to be able to produce N-rich toxins are lower in C:N, C:P and N:P relative to non-toxic species. These results indicate that any average estimate of dinoflagellate C:N:P will be influenced by the relative number of taxa with these traits.
{"title":"Traits influence dinoflagellate C:N:P","authors":"Olga Carnicer, A. Irwin, Z. Finkel","doi":"10.1080/09670262.2021.1914860","DOIUrl":"https://doi.org/10.1080/09670262.2021.1914860","url":null,"abstract":"ABSTRACT Dinoflagellates are amongst the most abundant and diverse groups of plankton in surface waters and contribute to food web productivity and C:N:P biogeochemistry. Here we analyse the C:N:P of marine, autotrophic, planktonic dinoflagellates compiled from culture data from the scientific literature and test if dinoflagellate C:N:P differs from the Redfield ratio, and whether variability in C:N:P is associated with three traits: cell size, wall structure and toxin production. We find the average C:N:P of dinoflagellates is 90:12:1; higher in C:N, and lower in C:P and N:P than the canonical Redfield ratio. In aggregate the three traits examined here account for between 20–31% while taxonomic order accounts for between 37–38% of the variance in C:N:P. Smaller-sized and thecate taxa are higher in C:N, C:P and N:P than larger-size and athecate taxa. Species known to be able to produce C-rich toxins tend to be higher in C:P and N:P while species known to be able to produce N-rich toxins are lower in C:N, C:P and N:P relative to non-toxic species. These results indicate that any average estimate of dinoflagellate C:N:P will be influenced by the relative number of taxa with these traits.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2021-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09670262.2021.1914860","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41504505","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 : 2021-05-12DOI: 10.1080/09670262.2021.1898677
Anna Busch, Sebastian Hess
Abstract Terrestrial microalgae evolved a variety of photoprotective strategies enabling a life on land. This includes the production of sunscreen compounds, which shield cells from excess radiation. Here, we report a new genus of conjugating green algae, Serritaenia gen. nov., whose members produce extracellular mucilage with a striking pigmentation. This phenomenon is very unusual for eukaryotic algae and poses cell biological and functional questions. So far, extracellular sunscreen pigments are exclusively known from cyanobacteria, while eukaryotic algae typically contain intracellular sunscreens. We demonstrate that pigmented mucilage in Serritaenia spp. can be induced by experimental exposure to UVB in an intensity-dependent manner, and that it strongly absorbs deleterious wavebands. Microscopic details of UVR-treated cells suggest that the directional secretion of pigmented mucilage is responsible for the defined and well-oriented pigment layers observed in natural material. Even though the chemical nature of the pigment remains to be elucidated, several pieces of evidence suggest that the ‘sunscreen mucilage’ of Serritaenia represents an elaborate photoprotective adaptation, unprecedented in eukaryotic algae.
陆生微藻进化出多种光保护策略，使其能够在陆地上生存。这包括产生防晒化合物，保护细胞免受过量辐射。在这里，我们报告了一个新的结合绿藻属，Serritaenia gen. nov.，其成员产生具有显著色素沉着的细胞外粘液。这种现象在真核藻类中是非常罕见的，并提出了细胞生物学和功能问题。到目前为止，细胞外防晒色素只从蓝藻中发现，而真核藻类通常含有细胞内防晒霜。我们证明了Serritaenia spp.的色素黏液可以通过实验暴露于UVB以强度依赖的方式诱导，并且它强烈吸收有害波段。uvr处理细胞的微观细节表明，在天然物质中观察到的明确和定向的色素层是由色素黏液的定向分泌引起的。尽管色素的化学性质仍有待阐明，但一些证据表明，Serritaenia的“防晒粘液”代表了一种精细的光保护适应，这在真核藻类中是前所未有的。
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Pub Date : 2021-05-10DOI: 10.1080/09670262.2021.1885066
K. Zonneveld, J. Meilland, B. Donner, G. Versteegh
Abstract To better understand production, succession, excystment and transport of dinoflagellate cysts (dinocysts) and planktonic foraminifera in the upper water column, we investigated their fluxes during a 7-day survey in the active upwelling off Cape Blanc (NW Africa) in November 2018 with drifting traps at 100 m, 200 m and 400 m water depth. The survey covered a change from active upwelling to stratified conditions. Highest production of organic dinocysts and planktonic foraminifera was observed during active upwelling conditions and decreased drastically towards the end of the survey. Calcareous dinocysts appeared later during upwelling relaxation. Cytoplasm-bearing (full) dinocysts and foraminifera were produced in the water column above the traps (<100 m depth). Some of the empty dinocysts were resuspended, implying that sediments below the survey site contain both local and allochthonous cyst assemblages. This is the first demonstration that excystment in the upper water column is species-specific. Brigantedinium excysted in the upper water column before reaching deeper depths, whereas no upper water column excystment was observed for the other dinoflagellate species. Dinoflagellate and planktonic foraminifera associations showed a clear succession. During active upwelling, Echinidinium zonneveldiae, Brigantedinium spp., other peridinioids, Echinidinium spp., cysts of Pentapharsodinium dalei, ‘other photosynthetic organic-walled dinocysts‘, Neogloboquadrina incompta and Globigerinella calida were collected. During upwelling relaxation, Lingulodinium machaerophorum was produced; and under stratified conditions Gymnodiniaceae cysts (G. microreticulatum, G. catenatum) and the foraminifera Globigerina bulloides and Orbulina universa were sampled. Apart from enhancing knowledge of these species, our observations allow more detailed reconstructions of upwelling history in the Cape Blanc region based on sedimentary archives using fossilized dinoflagellate and planktonic foraminifera assemblages.
{"title":"Export flux succession of dinoflagellate cysts and planktonic foraminifera in an active upwelling cell off Cape Blanc (NW Africa)","authors":"K. Zonneveld, J. Meilland, B. Donner, G. Versteegh","doi":"10.1080/09670262.2021.1885066","DOIUrl":"https://doi.org/10.1080/09670262.2021.1885066","url":null,"abstract":"Abstract To better understand production, succession, excystment and transport of dinoflagellate cysts (dinocysts) and planktonic foraminifera in the upper water column, we investigated their fluxes during a 7-day survey in the active upwelling off Cape Blanc (NW Africa) in November 2018 with drifting traps at 100 m, 200 m and 400 m water depth. The survey covered a change from active upwelling to stratified conditions. Highest production of organic dinocysts and planktonic foraminifera was observed during active upwelling conditions and decreased drastically towards the end of the survey. Calcareous dinocysts appeared later during upwelling relaxation. Cytoplasm-bearing (full) dinocysts and foraminifera were produced in the water column above the traps (<100 m depth). Some of the empty dinocysts were resuspended, implying that sediments below the survey site contain both local and allochthonous cyst assemblages. This is the first demonstration that excystment in the upper water column is species-specific. Brigantedinium excysted in the upper water column before reaching deeper depths, whereas no upper water column excystment was observed for the other dinoflagellate species. Dinoflagellate and planktonic foraminifera associations showed a clear succession. During active upwelling, Echinidinium zonneveldiae, Brigantedinium spp., other peridinioids, Echinidinium spp., cysts of Pentapharsodinium dalei, ‘other photosynthetic organic-walled dinocysts‘, Neogloboquadrina incompta and Globigerinella calida were collected. During upwelling relaxation, Lingulodinium machaerophorum was produced; and under stratified conditions Gymnodiniaceae cysts (G. microreticulatum, G. catenatum) and the foraminifera Globigerina bulloides and Orbulina universa were sampled. Apart from enhancing knowledge of these species, our observations allow more detailed reconstructions of upwelling history in the Cape Blanc region based on sedimentary archives using fossilized dinoflagellate and planktonic foraminifera assemblages.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09670262.2021.1885066","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45603889","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 : 2021-04-28DOI: 10.1080/09670262.2021.1883742
N. Win, M. Wai, P. J. Geraldino, L. Liao, C. Aye, Ni Ni Mar, T. Hanyuda, H. Kawai, M. Tokeshi
ABSTRACT Taxonomy, species diversity, and geographical distribution of the marine brown algal genus Padina (Dictyotales, Phaeophyceae) from tropical South-East Asian waters were investigated through a combination of morphological and molecular analyses. The study presents a new schematic diagram showing a suite of morphological characters including thallus hairline structures that are useful for species delineation in the genus. This study also revealed two new species from Myanmar, P. gracilis sp. nov. and P. lata sp. nov. based on molecular and morphological data. P. gracilis is characterised by a 2-layered thallus, thin hairlines on both surfaces of the thallus at equal distances, non-indusiate reproductive sori distally very close to the hairlines on the inferior surface, and the presence of Vaughaniella stage. P. lata is characterized by a 2–4-layered tiny thallus, broad hairlines located only on the inferior thallus surface, non-indusiate reproductive sori abutting the hairlines on the inferior surface and irregularly spreading on the superior surface, and the presence of Vaughaniella stage. This study also revealed new distributional records for four Padina species: P. okinawaensis from Myanmar and P. fasciata, P. ryukyuana and P. terricolor from the Philippines. These findings point to elevated species diversity in central Indo-Pacific waters. This study confirmed that most of the Padina species in the Pacific regions are showing overlapping distribution across the regions, in contrast to species from the Indian Ocean, which tend to be confined to specific localities.
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Pub Date : 2021-04-28DOI: 10.1080/09670262.2021.1896787
I. J. Melero-Jiménez, Elena Martín‐Clemente, A. Reul, M. García-Sánchez, A. Flores‐Moya, E. Bañares‐España
ABSTRACT Evolutionary rescue (ER) occurs when adaptation prevents extinction under lethal selection. However, the lack of empirical studies addressing the possible factors enabling ER limits our understanding of the current biodiversity crisis in the context of global change. Here we addressed the roles of environmental deterioration rate and dispersal of metapopulations on the dynamics of ER in the freshwater cyanobacterium Microcystis aeruginosa exposed to lethal salinity levels. We exposed M. aeruginosa to six combinations of two environmental deterioration rates (control = no deterioration, and progressive deterioration). Populations under progressive deterioration started with five different NaCl concentrations (from 0 to 4 g l–1 NaCl), with 2 g l–1 NaCl added twice at 4-week intervals, followed by a final increase of 4 g l–1 NaCl. Final concentrations in the experiment ranged from 8 to 12 g l–1 NaCl. Populations with no deterioration treatment spent 12 weeks in the initial concentration and were suddenly shifted to the final range concentration. To determine the effects of dispersal on the number of ER events, three dispersal modes were implemented: (i) populations were not mixed (no dispersal); (ii) six replicate populations of the same NaCl concentration were mixed together (local dispersal); and (iii) all populations of the same metapopulation were mixed together (global dispersal). Both dispersal mode and deterioration rate were very strong predictors of the ER outcome in each metapopulation. Specifically, dispersal among populations and prior stress exposure favoured the occurrence of ER events.
进化拯救(Evolutionary rescue, ER)是指在致死选择下，适应阻止了物种灭绝。然而，缺乏实证研究解决了可能的因素，限制了我们对当前全球变化背景下生物多样性危机的理解。本文研究了环境恶化率和超种群扩散对暴露于致死盐度水平的淡水蓝藻绿微囊藻内质网动态的影响。我们将铜绿假单胞菌暴露于两种环境恶化率(对照=无恶化和渐进性恶化)的六种组合中。进行性退化群体从5种不同的NaCl浓度(0 ~ 4 g l-1 NaCl)开始，每4周添加2次2 g l-1 NaCl，最后增加4 g l-1 NaCl。实验最终浓度为8 ~ 12 g l-1 NaCl。未恶化处理的种群在初始浓度下停留12周，然后突然转移到最终范围浓度。为了确定扩散对ER事件数量的影响，采用了三种扩散模式:(i)种群不混合(不扩散);(ii)将相同NaCl浓度的6个重复群体混合在一起(局部分散);(iii)同一元种群的所有种群混合在一起(全球分散)。扩散模式和恶化率都是每个元种群ER结果的非常强的预测因子。具体来说，种群间的分散和先前的应激暴露有利于内质网事件的发生。
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