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":"57 1","pages":"125 - 142"},"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":"57 1","pages":"154 - 165"},"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。
{"title":"Sunscreen mucilage: a photoprotective adaptation found in terrestrial green algae (Zygnematophyceae)","authors":"Anna Busch, Sebastian Hess","doi":"10.1080/09670262.2021.1898677","DOIUrl":"https://doi.org/10.1080/09670262.2021.1898677","url":null,"abstract":"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.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"57 1","pages":"107 - 124"},"PeriodicalIF":2.4,"publicationDate":"2021-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09670262.2021.1898677","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43448165","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 : 2021-05-10DOI: 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":"57 1","pages":"29 - 47"},"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.
{"title":"Taxonomy and species diversity of Padina (Dictyotales, Phaeophyceae) from the Indo-Pacific with the description of two new species","authors":"N. Win, M. Wai, P. J. Geraldino, L. Liao, C. Aye, Ni Ni Mar, T. Hanyuda, H. Kawai, M. Tokeshi","doi":"10.1080/09670262.2021.1883742","DOIUrl":"https://doi.org/10.1080/09670262.2021.1883742","url":null,"abstract":"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.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"57 1","pages":"1 - 17"},"PeriodicalIF":2.4,"publicationDate":"2021-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09670262.2021.1883742","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44813966","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: 10.1080/09670262.2021.1896787
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。
{"title":"Dispersal of populations and environmental deterioration rate influence evolutionary rescue under selection by salinity in the freshwater cyanobacterium Microcystis aeruginosa","authors":"I. J. Melero-Jiménez, Elena Martín‐Clemente, A. Reul, M. García-Sánchez, A. Flores‐Moya, E. Bañares‐España","doi":"10.1080/09670262.2021.1896787","DOIUrl":"https://doi.org/10.1080/09670262.2021.1896787","url":null,"abstract":"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.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"57 1","pages":"96 - 106"},"PeriodicalIF":2.4,"publicationDate":"2021-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09670262.2021.1896787","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44381422","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 : 2021-04-12DOI: 10.1080/09670262.2021.1891462
Feresa P. Cabrera, J. Huisman, Heather L. Spalding, R. Kosaki, A. Sherwood
ABSTRACT Small red algal morphologically variable blades have been extensively collected from Hawaiian reefs, but for many specimens their taxonomy remains poorly understood. In surveys of the Papahānaumokuākea Marine National Monument (PMNM) and Main Hawaiian Islands (MHI), we discovered two taxa of undescribed small (< 5 cm) red blades that matched the genera Psaromenia and Meredithia, based on morphology and molecular analyses. Neither genus has been previously recorded in the Hawaiian Islands, and neither group of specimens matched currently described species in these two genera. Accordingly, these specimens are described here as new species within the family Kallymeniaceae. Psaromenia laulamaula sp. nov., exclusively found at mesophotic depths (83–94 m) in PMNM, is easily distinguished from other members of the genus by its comparatively large, procarpic carpogonial branch system and solitary obovate pink-to-magenta blades. Conversely, Meredithia hawaiiensis sp. nov., occurring in both shallow (0–17 m) and mesophotic depths (55 m), has high morphological plasticity, with characters that overlap with other Meredithia species, and can only be distinguished based on DNA sequences. This study provides additional evidence of the extent of diversity in the Kallymeniaceae that is poorly characterized from mesophotic depths and provides further evidence that members of the macroalgal flora contain overlooked biodiversity.
{"title":"Diversity of Kallymeniaceae (Gigartinales, Rhodophyta) associated with Hawaiian mesophotic reefs","authors":"Feresa P. Cabrera, J. Huisman, Heather L. Spalding, R. Kosaki, A. Sherwood","doi":"10.1080/09670262.2021.1891462","DOIUrl":"https://doi.org/10.1080/09670262.2021.1891462","url":null,"abstract":"ABSTRACT Small red algal morphologically variable blades have been extensively collected from Hawaiian reefs, but for many specimens their taxonomy remains poorly understood. In surveys of the Papahānaumokuākea Marine National Monument (PMNM) and Main Hawaiian Islands (MHI), we discovered two taxa of undescribed small (< 5 cm) red blades that matched the genera Psaromenia and Meredithia, based on morphology and molecular analyses. Neither genus has been previously recorded in the Hawaiian Islands, and neither group of specimens matched currently described species in these two genera. Accordingly, these specimens are described here as new species within the family Kallymeniaceae. Psaromenia laulamaula sp. nov., exclusively found at mesophotic depths (83–94 m) in PMNM, is easily distinguished from other members of the genus by its comparatively large, procarpic carpogonial branch system and solitary obovate pink-to-magenta blades. Conversely, Meredithia hawaiiensis sp. nov., occurring in both shallow (0–17 m) and mesophotic depths (55 m), has high morphological plasticity, with characters that overlap with other Meredithia species, and can only be distinguished based on DNA sequences. This study provides additional evidence of the extent of diversity in the Kallymeniaceae that is poorly characterized from mesophotic depths and provides further evidence that members of the macroalgal flora contain overlooked biodiversity.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"57 1","pages":"68 - 78"},"PeriodicalIF":2.4,"publicationDate":"2021-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09670262.2021.1891462","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48867653","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 : 2021-04-12DOI: 10.1080/09670262.2021.1882704
Trevor T. Bringloe, Ryan Sauermann, D. Krause‐Jensen, B. Olesen, A. Klimova, T. Klochkova, Heroen Verbruggen
ABSTRACT Whole genome sequencing datasets present the opportunity to not only study evolution in the target organism, but also the associated holobiont. The capacity to study epi-endobiotic kelp associations is improving substantially with the increased availability of high-throughput sequencing datasets. The goal of this study was to determine if shotgun sequencing libraries could be used to document epi- and endophyte/faunal species colonizing Alaria kelp sporophytes from Kamchatka (Russia), the Bay of Fundy (Atlantic Canada) and Nuuk (Greenland). Mitochondrial coxI and plastid rbcL reads were extracted and assembled from six Alaria whole genome sequencing datasets. In total, contigs representing 11 epi-endobiotic species were assembled, of which Chordariacean diversity dominated. Given the presence of a newly discovered phaeophycean coxI sequence lacking an rbcL counterpart, we secondarily tested our hypothesis that the coxI sequence belonged to a phaeophycean parasite. The entire read dataset was assembled for the Alaria specimen hosting the putative parasite, the mitochondrial genome was retrieved, and plastid scaffolds were annotated and screened for phylogenetic placement matching the coxI sequence. The mitochondrial genome of the candidate parasite displayed numerous atypical features, including duplicated genes and rearrangements, and clear signs of relaxed selection, in line with the notion this organism may have a deviant lifestyle. The plastid genome was recovered as several fragments and lacked genes for photosystem and cytochrome complexes and chlorophyll biosynthesis, confirming our hypothesis that the unknown phaeophycean represented a parasitic species. Furthermore, classification to order remained unclear for the phaeophycean parasite, suggesting this species could represent a newly discovered higher-level lineage. Our study showcases the utility of whole-genome sequencing datasets in revealing surprising aspects of the eukaryotic diversity inhabiting kelp holobionts.
{"title":"High-throughput sequencing of the kelp Alaria (Phaeophyceae) reveals epi-endobiotic associations, including a likely phaeophycean parasite","authors":"Trevor T. Bringloe, Ryan Sauermann, D. Krause‐Jensen, B. Olesen, A. Klimova, T. Klochkova, Heroen Verbruggen","doi":"10.1080/09670262.2021.1882704","DOIUrl":"https://doi.org/10.1080/09670262.2021.1882704","url":null,"abstract":"ABSTRACT Whole genome sequencing datasets present the opportunity to not only study evolution in the target organism, but also the associated holobiont. The capacity to study epi-endobiotic kelp associations is improving substantially with the increased availability of high-throughput sequencing datasets. The goal of this study was to determine if shotgun sequencing libraries could be used to document epi- and endophyte/faunal species colonizing Alaria kelp sporophytes from Kamchatka (Russia), the Bay of Fundy (Atlantic Canada) and Nuuk (Greenland). Mitochondrial coxI and plastid rbcL reads were extracted and assembled from six Alaria whole genome sequencing datasets. In total, contigs representing 11 epi-endobiotic species were assembled, of which Chordariacean diversity dominated. Given the presence of a newly discovered phaeophycean coxI sequence lacking an rbcL counterpart, we secondarily tested our hypothesis that the coxI sequence belonged to a phaeophycean parasite. The entire read dataset was assembled for the Alaria specimen hosting the putative parasite, the mitochondrial genome was retrieved, and plastid scaffolds were annotated and screened for phylogenetic placement matching the coxI sequence. The mitochondrial genome of the candidate parasite displayed numerous atypical features, including duplicated genes and rearrangements, and clear signs of relaxed selection, in line with the notion this organism may have a deviant lifestyle. The plastid genome was recovered as several fragments and lacked genes for photosystem and cytochrome complexes and chlorophyll biosynthesis, confirming our hypothesis that the unknown phaeophycean represented a parasitic species. Furthermore, classification to order remained unclear for the phaeophycean parasite, suggesting this species could represent a newly discovered higher-level lineage. Our study showcases the utility of whole-genome sequencing datasets in revealing surprising aspects of the eukaryotic diversity inhabiting kelp holobionts.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"56 1","pages":"494 - 504"},"PeriodicalIF":2.4,"publicationDate":"2021-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09670262.2021.1882704","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43971849","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 : 2021-04-06DOI: 10.1080/09670262.2021.1885065
Eduardo Caffagni Camargo, R. Rossi, Jaqueline C. Silva, A. C. P. Miwa, O. Prášil, M. Calijuri, A. T. Lombardi
ABSTRACT Integration of pulse amplitude modulated (PAM) fluorometry and conventional methods for estimating carbon assimilation in microalgae is important for physiological, ecological and economic purposes. In this study, we compared PAM fluorometry and carbon-14 (14C) uptake techniques to estimate the carbon fixation rate in Chlorella vulgaris under controlled laboratory conditions. The key parameter for this comparison was the electron yield for carbon fixation (Фe ), commonly assumed when converting electron transport rate (ETR) values into the chlorophyll-specific carbon fixation rate (PB ). Additional analyses of maximum (ΦM ) and effective (Φ’M ) quantum efficiency of photosystem II, photochemical (qP) and non-photochemical (NPQ) quenching, and photosynthesis-irradiance response curves demonstrated that the photophysiology of C. vulgaris did not change after a 2-h incubation with NaH14CO3 and Na2CO3 (control). The association of PB obtained through the 14C method (151 ± 8.77 µmol C [mg chl a]–1 h–1) with ETR (411 ± 3.91 µmol e− [mg chl a]–1 h–1) resulted in an average Фe of 0.37 ± 0.02 µmol C [µmol e−]–1, which is higher than theoretical Фe values usually reported in the literature (e.g. 0.20 and 0.25). We attributed this discrepancy to a possible inaccuracy in ETR due to underestimated values of chlorophyll-specific absorption cross-section (a*) and the common assumption that only 50% of total light is absorbed by photosystem II. We here demonstrate the importance of associating chlorophyll fluorescence with other primary production techniques, so that adjustments to calculation procedures can be made in accordance to species-specific physiological traits and particularities regarding culturing conditions.
{"title":"Comparing pulse amplitude modulated (PAM) fluorometry with radiocarbon technique for determination of inorganic carbon fixation in Chlorella vulgaris (Trebouxiophyceae, Chlorophyta)","authors":"Eduardo Caffagni Camargo, R. Rossi, Jaqueline C. Silva, A. C. P. Miwa, O. Prášil, M. Calijuri, A. T. Lombardi","doi":"10.1080/09670262.2021.1885065","DOIUrl":"https://doi.org/10.1080/09670262.2021.1885065","url":null,"abstract":"ABSTRACT Integration of pulse amplitude modulated (PAM) fluorometry and conventional methods for estimating carbon assimilation in microalgae is important for physiological, ecological and economic purposes. In this study, we compared PAM fluorometry and carbon-14 (14C) uptake techniques to estimate the carbon fixation rate in Chlorella vulgaris under controlled laboratory conditions. The key parameter for this comparison was the electron yield for carbon fixation (Фe ), commonly assumed when converting electron transport rate (ETR) values into the chlorophyll-specific carbon fixation rate (PB ). Additional analyses of maximum (ΦM ) and effective (Φ’M ) quantum efficiency of photosystem II, photochemical (qP) and non-photochemical (NPQ) quenching, and photosynthesis-irradiance response curves demonstrated that the photophysiology of C. vulgaris did not change after a 2-h incubation with NaH14CO3 and Na2CO3 (control). The association of PB obtained through the 14C method (151 ± 8.77 µmol C [mg chl a]–1 h–1) with ETR (411 ± 3.91 µmol e− [mg chl a]–1 h–1) resulted in an average Фe of 0.37 ± 0.02 µmol C [µmol e−]–1, which is higher than theoretical Фe values usually reported in the literature (e.g. 0.20 and 0.25). We attributed this discrepancy to a possible inaccuracy in ETR due to underestimated values of chlorophyll-specific absorption cross-section (a*) and the common assumption that only 50% of total light is absorbed by photosystem II. We here demonstrate the importance of associating chlorophyll fluorescence with other primary production techniques, so that adjustments to calculation procedures can be made in accordance to species-specific physiological traits and particularities regarding culturing conditions.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"57 1","pages":"18 - 28"},"PeriodicalIF":2.4,"publicationDate":"2021-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09670262.2021.1885065","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49367348","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 : 2021-04-03DOI: 10.1080/09670262.2020.1783460
V. Lokhande, C. Radhakrishnan, J. Kociolek, R. Lowe, B. Karthick
ABSTRACT Nine species of the diatom genus Luticola D.G.Mann were collected from wet walls and other subaerial habitats from the Western Ghats of India and analysed using light and scanning electron microscopy. Of these, seven are considered to be new species and they are formally described here. They are compared with congeners based on valve size and shape, and ultrastructural features. Another two species described previously by H.P. Gandhi and originally assigned to the genus Navicula are formally transferred to Luticola. Over 25 species of Luticola have been reported from south-east Asia, most of them endemic to the region. The morphological variation of the genus is considered along with its systematics, biogeography and ecology. It appears that south-east Asia, Antarctica and South America are the areas of endemism for this genus.
{"title":"The diatom genus Luticola D.G. Mann (Bacillariophyceae) in the Western Ghats of India and its biogeography","authors":"V. Lokhande, C. Radhakrishnan, J. Kociolek, R. Lowe, B. Karthick","doi":"10.1080/09670262.2020.1783460","DOIUrl":"https://doi.org/10.1080/09670262.2020.1783460","url":null,"abstract":"ABSTRACT Nine species of the diatom genus Luticola D.G.Mann were collected from wet walls and other subaerial habitats from the Western Ghats of India and analysed using light and scanning electron microscopy. Of these, seven are considered to be new species and they are formally described here. They are compared with congeners based on valve size and shape, and ultrastructural features. Another two species described previously by H.P. Gandhi and originally assigned to the genus Navicula are formally transferred to Luticola. Over 25 species of Luticola have been reported from south-east Asia, most of them endemic to the region. The morphological variation of the genus is considered along with its systematics, biogeography and ecology. It appears that south-east Asia, Antarctica and South America are the areas of endemism for this genus.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":"56 1","pages":"142 - 158"},"PeriodicalIF":2.4,"publicationDate":"2021-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09670262.2020.1783460","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47933712","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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