Pub Date : 2022-08-10DOI: 10.1080/09670262.2022.2092216
C. Vieira, O. De Clerck, Antoine de Ramon N’Yeurt, S. D’hondt, L. Millet, M. Kim, C. Payri, M. Zubia
ABSTRACT We re-evaluated the diversity of Lobophora using an integrative taxonomic approach based on a broad sampling across French Polynesian archipelagos. Our results show that French Polynesia supports at least 37 Lobophora species of which ~57% (21) are endemic. This level of endemicity is comparable to that presently known in the Caribbean and the western Indian Ocean, while French Polynesian coastlines cover a much smaller length. With a third of the species in common, French Polynesia shares considerable biogeographic affinities with the Melanesian Islands, situated over 4000 km to the west. Distribution ranges of a few species reach the western Indian Ocean, and two species also occur in the Atlantic. We hypothesize that Lobophora species in French Polynesia have mainly evolved into endemic species from colonizers originating from the Central Indo-Pacific. These rare dispersal events to ocean archipelagos followed by a long period of isolation and speciation represent an important process responsible for the high level of endemism in remote archipelagos. While south-eastern Pacific Islands could be considered an ‘evolutionary graveyard’ for the genus Lobophora as little local radiation occurred, this may simply be due to recent evolutionary history. Based on these new data, the diversity of Lobophora represents ~10% of French Polynesian seaweed diversity. Eighteen new species of Lobophora are here described from French Polynesia. Highlights Lobophora species diversity and biogeography in French Polynesia were investigated. Twenty-three species of Lobophora were newly identified, and 18 new species were described. This is the first inter-archipelago diversity and biogeographic study for a macroalgal genus in the French Polynesian region.
{"title":"Diversity, systematics and biogeography of French Polynesian Lobophora (Dictyotales, Phaeophyceae)","authors":"C. Vieira, O. De Clerck, Antoine de Ramon N’Yeurt, S. D’hondt, L. Millet, M. Kim, C. Payri, M. Zubia","doi":"10.1080/09670262.2022.2092216","DOIUrl":"https://doi.org/10.1080/09670262.2022.2092216","url":null,"abstract":"ABSTRACT We re-evaluated the diversity of Lobophora using an integrative taxonomic approach based on a broad sampling across French Polynesian archipelagos. Our results show that French Polynesia supports at least 37 Lobophora species of which ~57% (21) are endemic. This level of endemicity is comparable to that presently known in the Caribbean and the western Indian Ocean, while French Polynesian coastlines cover a much smaller length. With a third of the species in common, French Polynesia shares considerable biogeographic affinities with the Melanesian Islands, situated over 4000 km to the west. Distribution ranges of a few species reach the western Indian Ocean, and two species also occur in the Atlantic. We hypothesize that Lobophora species in French Polynesia have mainly evolved into endemic species from colonizers originating from the Central Indo-Pacific. These rare dispersal events to ocean archipelagos followed by a long period of isolation and speciation represent an important process responsible for the high level of endemism in remote archipelagos. While south-eastern Pacific Islands could be considered an ‘evolutionary graveyard’ for the genus Lobophora as little local radiation occurred, this may simply be due to recent evolutionary history. Based on these new data, the diversity of Lobophora represents ~10% of French Polynesian seaweed diversity. Eighteen new species of Lobophora are here described from French Polynesia. Highlights Lobophora species diversity and biogeography in French Polynesia were investigated. Twenty-three species of Lobophora were newly identified, and 18 new species were described. This is the first inter-archipelago diversity and biogeographic study for a macroalgal genus in the French Polynesian region.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45622035","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 : 2022-07-26DOI: 10.1080/09670262.2022.2095442
R. Hoffman, O. De Clerck, F. Leliaert
ABSTRACT We provide an account of two newly recorded non-indigenous tropical seaweed species, Siphonocladus tropicus (Cladophorales, Chlorophyta) and Caulerpa integerrima (Caulerpaceae, Chlorophyta), from the northern and central Levantine Mediterranean shores of Israel. Reports are supported by morphological and molecular evidence. The new record of C. integerrima, thought to be endemic to the Red Sea, increases the number of non-indigenous Caulerpa species in the Mediterranean Sea to eight. Siphonocladus tropicus, a widespread tropical species, is also being reported from the northern Red Sea. Furthermore, morphological comparison of populations from the northern Red Sea and the Levantine Mediterranean shore of Israel revealed that there might be a regional variant or form of this species in the northern Red Sea and might indicate that this new invader does not necessarily originate from the Red Sea. The increasingly tropical conditions in the eastern Levantine Sea as a result of global warming probably paved the way for the establishment of both species in the region. Aspects of the new invaders’ ecology in the Israeli Levantine Sea, the possible vectors of introduction and origins, as well as the status of other Caulerpa species from both Levantine and Red Sea shores, are discussed. HIGHLIGHTS Siphonocladus tropicus and Caulerpa integerrima are new non-native species found lately in the Mediterranean Sea. Caulerpa integerrima originated from the Red Sea whereas the origin of Siphonocladus tropicus is uncertain. The introduction of these two alien species, especially Caulerpa integerrima, might pose a threat to the local marine flora and fauna.
{"title":"First records of the non-indigenous green algal species Siphonocladus tropicus (Cladophorales, Chlorophyta) and Caulerpa integerrima (Bryopsidales, Chlorophyta) in the Mediterranean Sea","authors":"R. Hoffman, O. De Clerck, F. Leliaert","doi":"10.1080/09670262.2022.2095442","DOIUrl":"https://doi.org/10.1080/09670262.2022.2095442","url":null,"abstract":"ABSTRACT We provide an account of two newly recorded non-indigenous tropical seaweed species, Siphonocladus tropicus (Cladophorales, Chlorophyta) and Caulerpa integerrima (Caulerpaceae, Chlorophyta), from the northern and central Levantine Mediterranean shores of Israel. Reports are supported by morphological and molecular evidence. The new record of C. integerrima, thought to be endemic to the Red Sea, increases the number of non-indigenous Caulerpa species in the Mediterranean Sea to eight. Siphonocladus tropicus, a widespread tropical species, is also being reported from the northern Red Sea. Furthermore, morphological comparison of populations from the northern Red Sea and the Levantine Mediterranean shore of Israel revealed that there might be a regional variant or form of this species in the northern Red Sea and might indicate that this new invader does not necessarily originate from the Red Sea. The increasingly tropical conditions in the eastern Levantine Sea as a result of global warming probably paved the way for the establishment of both species in the region. Aspects of the new invaders’ ecology in the Israeli Levantine Sea, the possible vectors of introduction and origins, as well as the status of other Caulerpa species from both Levantine and Red Sea shores, are discussed. HIGHLIGHTS Siphonocladus tropicus and Caulerpa integerrima are new non-native species found lately in the Mediterranean Sea. Caulerpa integerrima originated from the Red Sea whereas the origin of Siphonocladus tropicus is uncertain. The introduction of these two alien species, especially Caulerpa integerrima, might pose a threat to the local marine flora and fauna.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47955159","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 : 2022-07-25DOI: 10.1080/09670262.2022.2087907
C. Faraloni, G. Torzillo, A. Vonshak
ABSTRACT The genus Nannochloropsis (Eustigmatophyceae), including N. oceanica, has attracted considerable interest, due to its ability to accumulate high levels of lipids. Under large-scale cultivation outdoors, cells are exposed to a combination of high oxygen and light irradiance conditions that may promote photoinhibition, so selecting strains able to tolerate oxidative stress is desirable. Rose bengal (RB) reacts with oxygen to form singlet oxygen in the presence of light. Therefore, RB can be a very useful tool for testing the sensitivity of algae to oxidative stress and thus identify strains capable of photosynthesis under oxidative stress. In this study, two mutants of N. oceanica, RB2 and RB113, which are resistant to high concentrations of rose bengal, were phenotypically characterized for their sensitivity to high oxygen concentrations. Both strains exhibited levels of catalase and ascorbate peroxidase 1.5- and 3-fold higher, respectively, than the wild type. In addition, the synthesis of carotenoids was lower than in the wild type, indicating lower oxidative stress. These results were confirmed by chlorophyll fluorescence measurements, which indicated a lower sensitivity of the photosynthetic apparatus of the mutants, especially of RB2, even in the presence of H2O2. The results support the hypothesis that resistance to rose bengal may also induce resistance to high dissolved oxygen stress. The ability shown by the mutants to perform photosynthesis more efficiently under high oxygen stress than the wild type makes them promising candidates for outdoor cultures.
{"title":"Nannochloropsis oceanica (Eustigmatophyceae) mutants resistant to rose bengal demonstrate high tolerance to oxygen","authors":"C. Faraloni, G. Torzillo, A. Vonshak","doi":"10.1080/09670262.2022.2087907","DOIUrl":"https://doi.org/10.1080/09670262.2022.2087907","url":null,"abstract":"ABSTRACT The genus Nannochloropsis (Eustigmatophyceae), including N. oceanica, has attracted considerable interest, due to its ability to accumulate high levels of lipids. Under large-scale cultivation outdoors, cells are exposed to a combination of high oxygen and light irradiance conditions that may promote photoinhibition, so selecting strains able to tolerate oxidative stress is desirable. Rose bengal (RB) reacts with oxygen to form singlet oxygen in the presence of light. Therefore, RB can be a very useful tool for testing the sensitivity of algae to oxidative stress and thus identify strains capable of photosynthesis under oxidative stress. In this study, two mutants of N. oceanica, RB2 and RB113, which are resistant to high concentrations of rose bengal, were phenotypically characterized for their sensitivity to high oxygen concentrations. Both strains exhibited levels of catalase and ascorbate peroxidase 1.5- and 3-fold higher, respectively, than the wild type. In addition, the synthesis of carotenoids was lower than in the wild type, indicating lower oxidative stress. These results were confirmed by chlorophyll fluorescence measurements, which indicated a lower sensitivity of the photosynthetic apparatus of the mutants, especially of RB2, even in the presence of H2O2. The results support the hypothesis that resistance to rose bengal may also induce resistance to high dissolved oxygen stress. The ability shown by the mutants to perform photosynthesis more efficiently under high oxygen stress than the wild type makes them promising candidates for outdoor cultures.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49235126","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 : 2022-07-25DOI: 10.1080/09670262.2022.2091798
Mariana S. Pandeirada, S. C. Craveiro, N. Daugbjerg, Ø. Moestrup, A. Calado
Abstract Recent molecular phylogenies that include species of Parvodinium revealed as its closest relatives the genera Peridiniopsis, Palatinus and Johsia. The clade containing these taxa is currently recognized as a family, Peridiniopsidaceae. The affinity between the members of Peridiniopsidaceae cuts across traditional boundaries based on features of the amphiesma, most notably the presence or absence of an apical pore complex. Detailed descriptions of the fine structure of Peridiniopsis and Palatinus are available from TEM studies of their type species. Here we provide a description in comparable detail of a species of the Parvodinium umbonatum–inconspicuum complex, which includes the type of the genus. The cells had an apical fibrous complex essentially similar to those described from other peridinioids prepared with comparable fixations. The pusular system was extensive and included areas with different aspects: an area with a sheet-like vesicle along the mid-right side of the cell, a ventral portion with ramified and anastomosed tubes and a somewhat flattened tube attached to the transverse flagellar canal. The most remarkable feature was the microtubular strand that extended from a ventral, protruding peduncle to the anterior part of the epicone, around an accumulation body, and came around along a more dorsal position toward the ventral side. This long microtubular strand of the peduncle (MSP) was reminiscent of the one described from Peridiniopsis borgei, both by its extension and looping path, and by the breaking up of the strand of microtubules into smaller portions with a wavy appearance; and contrasted with the reduced MSP of Palatinus apiculatus. The fine-structural features currently known from Peridiniopsidaceae are summarized. Members of the family include a flagellar apparatus with four microtubule-containing roots associated, the basal bodies inserted close to each other, nearly at right angles and a three-armed fibrous connective between root 1 and the transverse basal body. HIGHLIGHTS Detailed fine structure of Parvodinium (of P. umbonatum–P. inconspicuum complex). Comparative analysis of the ultrastructure of Parvodinium and other Peridiniopsidaceae. Summary of ultrastructural features of the family Peridiniopsidaceae.
{"title":"Cell fine structure and phylogeny of Parvodinium: towards an ultrastructural characterization of the Peridiniopsidaceae (Dinophyceae)","authors":"Mariana S. Pandeirada, S. C. Craveiro, N. Daugbjerg, Ø. Moestrup, A. Calado","doi":"10.1080/09670262.2022.2091798","DOIUrl":"https://doi.org/10.1080/09670262.2022.2091798","url":null,"abstract":"Abstract Recent molecular phylogenies that include species of Parvodinium revealed as its closest relatives the genera Peridiniopsis, Palatinus and Johsia. The clade containing these taxa is currently recognized as a family, Peridiniopsidaceae. The affinity between the members of Peridiniopsidaceae cuts across traditional boundaries based on features of the amphiesma, most notably the presence or absence of an apical pore complex. Detailed descriptions of the fine structure of Peridiniopsis and Palatinus are available from TEM studies of their type species. Here we provide a description in comparable detail of a species of the Parvodinium umbonatum–inconspicuum complex, which includes the type of the genus. The cells had an apical fibrous complex essentially similar to those described from other peridinioids prepared with comparable fixations. The pusular system was extensive and included areas with different aspects: an area with a sheet-like vesicle along the mid-right side of the cell, a ventral portion with ramified and anastomosed tubes and a somewhat flattened tube attached to the transverse flagellar canal. The most remarkable feature was the microtubular strand that extended from a ventral, protruding peduncle to the anterior part of the epicone, around an accumulation body, and came around along a more dorsal position toward the ventral side. This long microtubular strand of the peduncle (MSP) was reminiscent of the one described from Peridiniopsis borgei, both by its extension and looping path, and by the breaking up of the strand of microtubules into smaller portions with a wavy appearance; and contrasted with the reduced MSP of Palatinus apiculatus. The fine-structural features currently known from Peridiniopsidaceae are summarized. Members of the family include a flagellar apparatus with four microtubule-containing roots associated, the basal bodies inserted close to each other, nearly at right angles and a three-armed fibrous connective between root 1 and the transverse basal body. HIGHLIGHTS Detailed fine structure of Parvodinium (of P. umbonatum–P. inconspicuum complex). Comparative analysis of the ultrastructure of Parvodinium and other Peridiniopsidaceae. Summary of ultrastructural features of the family Peridiniopsidaceae.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45845312","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 : 2022-07-21DOI: 10.1080/09670262.2022.2092215
Jeffrey D. Leblond, Lindsey C. Elkins, Jori E. Graeff, Kyra Sabir
ABSTRACT The genus Amphidinium is shown in many phylogenies to be basal to other peridinin-containing, photosynthetic dinoflagellates as one of the first photosynthetic genera to arise after the evolution of heterotrophic genera. As part of our continuing examination of the plastid-associated galactolipids, namely mono- and digalactosyldiacylglycerol (MGDG and DGDG, respectively), in dinoflagellates, we here examine the galactolipid composition of members of the genus Amphidinium. We show that this genus is characterized by an abundance of 20:5(n-3)/18:5(n-3) and 20:5(n-3)/18:4(n-3) forms of MGDG and DGDG (with sn-1/sn-2 regiochemical specificity of fatty acids), but also sometimes with generally lesser amounts of some polyunsaturated C18/C18 forms, thus placing the examined species within a previously identified cluster of C20/C18 MGDG- and DGDG-containing, peridinin-containing dinoflagellates. We also show that Testudodinium testudo, previously known as Amphidinium testudo, conversely falls within a previously identified C18/C18 cluster, indicating a distinct difference in galactolipid biosynthesis capability. While it is likely that further revision of the genus may occur in the future and/or more basal peridinin-containing, photosynthetic genera may be discovered, at the current time Amphidinium is the currently agreed-upon most basal dinoflagellate genus for which isolates are available for biochemical characterization such as what we describe in this paper. Thus, because of the presumed basal position of the genus Amphidinium, we present a hypothesis that its galactolipids currently represent those that are ancestral to other genera of peridinin-containing dinoflagellates, including those within the C18/C18 cluster. Highlights Amphidinium species’ galactolipids reside within the C20/C18 peridinin dinoflagellate cluster. Conversely, Testudodinium testudo (formerly Amphidinium testudo) falls within the C18/C18 cluster. We hypothesize Amphidinium’s galactolipids as basal to other peridinin dinoflagellates.
{"title":"Galactolipids of the genus Amphidinium (Dinophyceae): an hypothesis that they are basal to those of other peridinin-containing dinoflagellates","authors":"Jeffrey D. Leblond, Lindsey C. Elkins, Jori E. Graeff, Kyra Sabir","doi":"10.1080/09670262.2022.2092215","DOIUrl":"https://doi.org/10.1080/09670262.2022.2092215","url":null,"abstract":"ABSTRACT The genus Amphidinium is shown in many phylogenies to be basal to other peridinin-containing, photosynthetic dinoflagellates as one of the first photosynthetic genera to arise after the evolution of heterotrophic genera. As part of our continuing examination of the plastid-associated galactolipids, namely mono- and digalactosyldiacylglycerol (MGDG and DGDG, respectively), in dinoflagellates, we here examine the galactolipid composition of members of the genus Amphidinium. We show that this genus is characterized by an abundance of 20:5(n-3)/18:5(n-3) and 20:5(n-3)/18:4(n-3) forms of MGDG and DGDG (with sn-1/sn-2 regiochemical specificity of fatty acids), but also sometimes with generally lesser amounts of some polyunsaturated C18/C18 forms, thus placing the examined species within a previously identified cluster of C20/C18 MGDG- and DGDG-containing, peridinin-containing dinoflagellates. We also show that Testudodinium testudo, previously known as Amphidinium testudo, conversely falls within a previously identified C18/C18 cluster, indicating a distinct difference in galactolipid biosynthesis capability. While it is likely that further revision of the genus may occur in the future and/or more basal peridinin-containing, photosynthetic genera may be discovered, at the current time Amphidinium is the currently agreed-upon most basal dinoflagellate genus for which isolates are available for biochemical characterization such as what we describe in this paper. Thus, because of the presumed basal position of the genus Amphidinium, we present a hypothesis that its galactolipids currently represent those that are ancestral to other genera of peridinin-containing dinoflagellates, including those within the C18/C18 cluster. Highlights Amphidinium species’ galactolipids reside within the C20/C18 peridinin dinoflagellate cluster. Conversely, Testudodinium testudo (formerly Amphidinium testudo) falls within the C18/C18 cluster. We hypothesize Amphidinium’s galactolipids as basal to other peridinin dinoflagellates.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45695404","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 : 2022-07-20DOI: 10.1080/09670262.2022.2089913
P. Pribyl, Lenka Procházková
ABSTRACT A new freshwater microalgal isolate, CCALA 1135, was characterized using a polyphasic approach (morphology, ultrastructure, fatty acid composition, 18S rRNA gene and rbcL analyses). Non-motile vegetative cells were spherical with thick, smooth cell walls lacking ornamentation, with multiple overlapping chloroplasts and sometimes more than one red globule in the cytoplasm. The nuclear and chloroplast envelopes formed a continuous membrane and there was no pyrenoid. These morphological and ultrastructural features indicated assignment to the class Eustigmatophyceae. The strain was, however, unique in its mode of reproduction: only zoospores were formed, but no autospores were observed (i.e. obligate zoospory, which is rare in the Eustigmatophyceae). The zoospores were relatively fragile and their morphology was similar to those of other members of the clade Goniochloridales (a clade name under the PhyloCode) that have been studied, being uniflagellate and lacking an eyespot. A very high proportion of polyunsaturated fatty acids (up to 57% of total fatty acids) was found, dominated by nutritionally valuable arachidonic and eicosapentaenoic acids, the latter being the most abundant FA (up to 35%) in the total profile. Phylogenetic analysis based on 18S rDNA and rbcL sequences confirmed that CCALA 1135 represents a new member of Goniochloridales clade IIc. Based on cellular morphology, ultrastructure and molecular data we propose this strain as a new species and new genus of the Eustigmatophyceae, Trebonskia zoosporica gen. et sp. nov. Our work is a step toward clarifying the taxonomy of a group of the Eustigmatophyceae with many unnamed strains awaiting characterization. Highlights A new genus and species of Eustigmatophyceae is described using a polyphasic approach. This isolate reproduces only by zoospores, a mode rare within Eustigmatophyceae. It contained a high proportion of nutritionally valuable polyunsaturated fatty acids.
摘要采用多相方法(形态学、超微结构、脂肪酸组成、18S rRNA基因和rbcL分析)对一种新的淡水微藻CCALA 1135进行了表征。不运动的营养细胞呈球形，细胞壁厚而光滑，没有纹饰，有多个重叠的叶绿体，有时细胞质中有一个以上的红色球体。核膜与叶绿体膜呈连续膜，无类pyrenox。这些形态和超微结构特征表明该植物属于真穗草纲。然而，该菌株的繁殖方式是独特的:只形成游动孢子，但没有观察到自孢子(即专性游动孢子，这在真真菌中很少见)。游动孢子相对脆弱，它们的形态与已经研究过的Goniochloridales分支的其他成员相似，都是单毛的，没有眼点。发现了非常高比例的多不饱和脂肪酸(高达总脂肪酸的57%)，主要是营养价值高的花生四烯酸和二十碳五烯酸，后者是总谱中最丰富的FA(高达35%)。基于18S rDNA和rbcL序列的系统发育分析证实，CCALA 1135是Goniochloridales IIc分支的一个新成员。基于细胞形态学、超微结构和分子数据，我们提出了该菌株作为真菌科(Eustigmatophyceae, Trebonskia zoosporica gen. et sp. 11)的新种和新属。我们的工作是澄清真菌科(Eustigmatophyceae)的一组分类的一步，还有许多未命名的菌株有待鉴定。利用多相方法描述了一种新属和新种。该分离株仅通过游动孢子繁殖，这种模式在真真菌科中很少见。它含有高比例的营养价值的多不饱和脂肪酸。
{"title":"Trebonskia zoosporica, gen. et sp. nov., a new member of the Goniochloridales (Eustigmatophyceae, Stramenopiles) with an unusual mode of reproduction","authors":"P. Pribyl, Lenka Procházková","doi":"10.1080/09670262.2022.2089913","DOIUrl":"https://doi.org/10.1080/09670262.2022.2089913","url":null,"abstract":"ABSTRACT A new freshwater microalgal isolate, CCALA 1135, was characterized using a polyphasic approach (morphology, ultrastructure, fatty acid composition, 18S rRNA gene and rbcL analyses). Non-motile vegetative cells were spherical with thick, smooth cell walls lacking ornamentation, with multiple overlapping chloroplasts and sometimes more than one red globule in the cytoplasm. The nuclear and chloroplast envelopes formed a continuous membrane and there was no pyrenoid. These morphological and ultrastructural features indicated assignment to the class Eustigmatophyceae. The strain was, however, unique in its mode of reproduction: only zoospores were formed, but no autospores were observed (i.e. obligate zoospory, which is rare in the Eustigmatophyceae). The zoospores were relatively fragile and their morphology was similar to those of other members of the clade Goniochloridales (a clade name under the PhyloCode) that have been studied, being uniflagellate and lacking an eyespot. A very high proportion of polyunsaturated fatty acids (up to 57% of total fatty acids) was found, dominated by nutritionally valuable arachidonic and eicosapentaenoic acids, the latter being the most abundant FA (up to 35%) in the total profile. Phylogenetic analysis based on 18S rDNA and rbcL sequences confirmed that CCALA 1135 represents a new member of Goniochloridales clade IIc. Based on cellular morphology, ultrastructure and molecular data we propose this strain as a new species and new genus of the Eustigmatophyceae, Trebonskia zoosporica gen. et sp. nov. Our work is a step toward clarifying the taxonomy of a group of the Eustigmatophyceae with many unnamed strains awaiting characterization. Highlights A new genus and species of Eustigmatophyceae is described using a polyphasic approach. This isolate reproduces only by zoospores, a mode rare within Eustigmatophyceae. It contained a high proportion of nutritionally valuable polyunsaturated fatty acids.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48559978","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 : 2022-07-20DOI: 10.1080/09670262.2022.2081731
R. Sánchez de Pedro, Andrea N. Fernández, M. García-Sánchez, A. Flores‐Moya, E. Bañares‐España
Abstract Thermotolerance acquisition is an important ecophysiological trait under global warming scenarios because it can allow organisms and populations to adapt, particularly during the most sensitive early stages of a life cycle. Here we used seasonality as a natural scenario to explore whether parental thermal histories can modulate thermotolerance of recruits of a canopy-forming intertidal seaweed (Fucus guiryi) across an ecologically relevant thermal gradient (15–28°C). For this purpose, we harvested embryos from parents after the periods of maximum and minimum accumulated heat exposure (late summer and late winter), and at the onset of summer. During early ontogeny we followed initial embryo size, internal nutrient content, survival, growth and developmental stages as performance metrics to address whether parental acclimation modulates thermal tolerance via provisioning or parental effects. Late winter recruits of F. guiryi exhibited the greatest thermotolerance, showing a broader range of optimal temperatures and higher upper thermal limits for growth and survival, probably associated with better provisioning from parental thalli. Physiological fitness of recruits decreased above 25°C, showing arrested growth, impaired development and dropping survival rates, but functional loss was more abrupt in early summer. Late summer responses confirmed that heat hardening occurs in natural populations, but at the seasonal scale the adaptive significance of this increased thermotolerance is much lower than that induced by winter parental provisioning. Heat-induced thermotolerance occurred from early to late summer due to parental exposure to warming. However, winter provisioning promoted greater thermotolerance acquisition. Exposure to moderate thermal stress at the onset of summer without prior seasonal acclimation resulted in minimum levels of thermal tolerance and loss of offspring fitness. While warmer winters might be neutral or benefit early development, increasing temperatures and poor nutritional conditions at the onset of the summer season may reduce survival and hamper population recruitment. Highlights Thermotolerance of Fucus guiryi increased towards the late cold season. Early summer recruits had the lowest survival under warming. Seasonal performance of recruits might be driven by parental environment.
{"title":"Parental environment modulates offspring thermal tolerance in a foundational intertidal seaweed","authors":"R. Sánchez de Pedro, Andrea N. Fernández, M. García-Sánchez, A. Flores‐Moya, E. Bañares‐España","doi":"10.1080/09670262.2022.2081731","DOIUrl":"https://doi.org/10.1080/09670262.2022.2081731","url":null,"abstract":"Abstract Thermotolerance acquisition is an important ecophysiological trait under global warming scenarios because it can allow organisms and populations to adapt, particularly during the most sensitive early stages of a life cycle. Here we used seasonality as a natural scenario to explore whether parental thermal histories can modulate thermotolerance of recruits of a canopy-forming intertidal seaweed (Fucus guiryi) across an ecologically relevant thermal gradient (15–28°C). For this purpose, we harvested embryos from parents after the periods of maximum and minimum accumulated heat exposure (late summer and late winter), and at the onset of summer. During early ontogeny we followed initial embryo size, internal nutrient content, survival, growth and developmental stages as performance metrics to address whether parental acclimation modulates thermal tolerance via provisioning or parental effects. Late winter recruits of F. guiryi exhibited the greatest thermotolerance, showing a broader range of optimal temperatures and higher upper thermal limits for growth and survival, probably associated with better provisioning from parental thalli. Physiological fitness of recruits decreased above 25°C, showing arrested growth, impaired development and dropping survival rates, but functional loss was more abrupt in early summer. Late summer responses confirmed that heat hardening occurs in natural populations, but at the seasonal scale the adaptive significance of this increased thermotolerance is much lower than that induced by winter parental provisioning. Heat-induced thermotolerance occurred from early to late summer due to parental exposure to warming. However, winter provisioning promoted greater thermotolerance acquisition. Exposure to moderate thermal stress at the onset of summer without prior seasonal acclimation resulted in minimum levels of thermal tolerance and loss of offspring fitness. While warmer winters might be neutral or benefit early development, increasing temperatures and poor nutritional conditions at the onset of the summer season may reduce survival and hamper population recruitment. Highlights Thermotolerance of Fucus guiryi increased towards the late cold season. Early summer recruits had the lowest survival under warming. Seasonal performance of recruits might be driven by parental environment.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45460987","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 : 2022-07-18DOI: 10.1080/09670262.2022.2086710
Lia P. Godinho, Lucía Soliño, Catarina Churro, V. Timóteo, Carolina Santos, Neide Gouveia, J. Diogène, Pedro Reis Costa
ABSTRACT The emerging threat of ciguatera poisoning (CP) in Europe has been associated with fish captured in the Canary Islands (Spain) and Selvagens Islands (Portugal). The first are heavily populated islands where numerous scientific studies have been carried out. Conversely, the Selvagens Islands as a nature reserve with low human pressure have been rarely surveyed in terms of the marine benthic microalgae, including the epiphytic ciguatera-causing dinoflagellate species. To investigate the harmful microalgal diversity of the Selvagens Islands, a scientific cruise to these remote islands took place in September, 2018. The Gambierdiscus species composition and distribution, and the associated epiphytic dinoflagellate community, were assessed using artificial substrate devices. Gambierdiscus cells were found in all samples, reaching concentrations of up to 725 cells 100 cm–2. G. australes was the only species identified after morphological and molecular analysis of the retrieved cultures. Species identification was confirmed by molecular characterization based on the LSU D8–D10 region. Nevertheless, phylogenetic studies indicated that some strains diverged from the G. australes clade suggesting genetic differentiation. Toxicity was estimated by neuro-2a cell-based assay in four strains, ranging from 2.46–83 fg of CTX1B eq. cell–1. The epiphytic dinoflagellate community that co-occurred with Gambierdiscus comprised other toxic or potentially toxic dinoflagellates, such as Ostreopsis, Prorocentrum, Amphidinium and Coolia species. Oceanographic and meteorological data were also obtained to characterize the occurrence of Gambierdiscus. This study is the first stage in understanding the role of the Selvagens Islands in the incubation and proliferation of the ciguatera-causing dinoflagellates Gambierdiscus in the NE Atlantic. Highlights The Selvagens Islands are a ciguatera hotspot in Europe. Gambierdiscus australes was the only species observed in the Selvagens Islands. Strains diverging from the G. australes clade suggest genetic differentiation.
{"title":"Distribution, identification and cytotoxicity of Gambierdiscus (Dinophyceae) in the Atlantic Selvagens Islands (Madeira, Portugal): a ciguatera gateway to Europe","authors":"Lia P. Godinho, Lucía Soliño, Catarina Churro, V. Timóteo, Carolina Santos, Neide Gouveia, J. Diogène, Pedro Reis Costa","doi":"10.1080/09670262.2022.2086710","DOIUrl":"https://doi.org/10.1080/09670262.2022.2086710","url":null,"abstract":"ABSTRACT The emerging threat of ciguatera poisoning (CP) in Europe has been associated with fish captured in the Canary Islands (Spain) and Selvagens Islands (Portugal). The first are heavily populated islands where numerous scientific studies have been carried out. Conversely, the Selvagens Islands as a nature reserve with low human pressure have been rarely surveyed in terms of the marine benthic microalgae, including the epiphytic ciguatera-causing dinoflagellate species. To investigate the harmful microalgal diversity of the Selvagens Islands, a scientific cruise to these remote islands took place in September, 2018. The Gambierdiscus species composition and distribution, and the associated epiphytic dinoflagellate community, were assessed using artificial substrate devices. Gambierdiscus cells were found in all samples, reaching concentrations of up to 725 cells 100 cm–2. G. australes was the only species identified after morphological and molecular analysis of the retrieved cultures. Species identification was confirmed by molecular characterization based on the LSU D8–D10 region. Nevertheless, phylogenetic studies indicated that some strains diverged from the G. australes clade suggesting genetic differentiation. Toxicity was estimated by neuro-2a cell-based assay in four strains, ranging from 2.46–83 fg of CTX1B eq. cell–1. The epiphytic dinoflagellate community that co-occurred with Gambierdiscus comprised other toxic or potentially toxic dinoflagellates, such as Ostreopsis, Prorocentrum, Amphidinium and Coolia species. Oceanographic and meteorological data were also obtained to characterize the occurrence of Gambierdiscus. This study is the first stage in understanding the role of the Selvagens Islands in the incubation and proliferation of the ciguatera-causing dinoflagellates Gambierdiscus in the NE Atlantic. Highlights The Selvagens Islands are a ciguatera hotspot in Europe. Gambierdiscus australes was the only species observed in the Selvagens Islands. Strains diverging from the G. australes clade suggest genetic differentiation.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45292908","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 : 2022-06-13DOI: 10.1080/09670262.2022.2076291
E. Greipel, J. Kutasi, K. Solymosi, H. Nagy, T. Felföldi
ABSTRACT Chlorococcum is a coccoid green algal genus, which contains almost 50 species. The genus is polyphyletic, but in a traditional sense, the cells are coccoid and non-motile with a cup-shape chloroplast in the vegetative stage, while the spores have chlamydomonad appearance. They are distributed worldwide mainly in terrestrial habitats, and the biotechnological potential of several strains has been reported. In this study, three new green algal strains from a shallow, temporary freshwater lake in Hungary are characterized using microscopic (light and transmission electron microscopy) and DNA-based methods (phylogenetic analysis of the ribosomal ITS region, the 18S ribosomal RNA and rbcL genes, and ITS secondary structure comparison). Based on the obtained results, one of the three new isolates is considered to represent a new species, which is described here as Chlorococcum szentendrense sp. nov.
{"title":"Hidden diversity of Chlorococcum (Chlorophyta) in a shallow temporary freshwater lake: description of Chlorococcum szentendrense sp. nov","authors":"E. Greipel, J. Kutasi, K. Solymosi, H. Nagy, T. Felföldi","doi":"10.1080/09670262.2022.2076291","DOIUrl":"https://doi.org/10.1080/09670262.2022.2076291","url":null,"abstract":"ABSTRACT Chlorococcum is a coccoid green algal genus, which contains almost 50 species. The genus is polyphyletic, but in a traditional sense, the cells are coccoid and non-motile with a cup-shape chloroplast in the vegetative stage, while the spores have chlamydomonad appearance. They are distributed worldwide mainly in terrestrial habitats, and the biotechnological potential of several strains has been reported. In this study, three new green algal strains from a shallow, temporary freshwater lake in Hungary are characterized using microscopic (light and transmission electron microscopy) and DNA-based methods (phylogenetic analysis of the ribosomal ITS region, the 18S ribosomal RNA and rbcL genes, and ITS secondary structure comparison). Based on the obtained results, one of the three new isolates is considered to represent a new species, which is described here as Chlorococcum szentendrense sp. nov.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44284692","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 : 2022-05-25DOI: 10.1080/09670262.2022.2065365
S. Barrientos, R. Barreiro, Cristina Piñeiro‐Corbeira
ABSTRACT Kelp forests, one of the world’s most productive ecosystems, have been in decline in many regions in recent years. Climate change, through steady sea warming or marine heatwaves, has led to the disappearance of entire populations, although kelp forest decline may also depend on non-climatic stressors such as grazing. Since the impacts of climate change are projected to continue to intensify for decades, marine protected areas (MPAs) have been suggested as a cost-effective strategy to boost the resilience of marine ecosystems. However, implementing an MPA does not guarantee that all components of the local community will benefit from it. In NW Spain, several stakeholders reported the decline of Laminaria ochroleuca inside the Islas Atlánticas Marine National Park in recent years, but the extent and possible drivers of this decline have not been investigated. Using a combination of quadrat-scale (abundance, biomass) and transect-scale (cover) seasonal surveys over one year, we found striking differences between L. ochroleuca reefs inside and outside the MPA. Populations outside the MPA were the typical canopy forests expected for a perennial kelp, stable year-round and composed mostly of adults. Inside the MPA, however, grazing prevented the canopy phase from being reached. Instead, only mid-sized young plants were detected in autumn, but most had disappeared by winter, and those that remained had been degraded by herbivores to mere blade-less stipes with no growth meristem that eventually perish. Further research seems warranted to monitor whether this phenomenon spreads to nearby kelp beds outside the MPA. Meanwhile, restoring MPA kelp reefs will more likely require efforts to reduce herbivore activity (e.g. translocations, exclusion devices) than to bolster kelp populations. HIGHLIGHTS • Kelp canopies recurrently failed inside a MPA in recent years.• Neither propagule supply nor environmental conditions explain the failure.• Grazers keep a canopy-free state by eradicating recently recruited kelps.
{"title":"Paradoxical failure of Laminaria ochroleuca (Laminariales, Phaeophyceae) to consolidate a kelp forest inside a Marine National Park","authors":"S. Barrientos, R. Barreiro, Cristina Piñeiro‐Corbeira","doi":"10.1080/09670262.2022.2065365","DOIUrl":"https://doi.org/10.1080/09670262.2022.2065365","url":null,"abstract":"ABSTRACT Kelp forests, one of the world’s most productive ecosystems, have been in decline in many regions in recent years. Climate change, through steady sea warming or marine heatwaves, has led to the disappearance of entire populations, although kelp forest decline may also depend on non-climatic stressors such as grazing. Since the impacts of climate change are projected to continue to intensify for decades, marine protected areas (MPAs) have been suggested as a cost-effective strategy to boost the resilience of marine ecosystems. However, implementing an MPA does not guarantee that all components of the local community will benefit from it. In NW Spain, several stakeholders reported the decline of Laminaria ochroleuca inside the Islas Atlánticas Marine National Park in recent years, but the extent and possible drivers of this decline have not been investigated. Using a combination of quadrat-scale (abundance, biomass) and transect-scale (cover) seasonal surveys over one year, we found striking differences between L. ochroleuca reefs inside and outside the MPA. Populations outside the MPA were the typical canopy forests expected for a perennial kelp, stable year-round and composed mostly of adults. Inside the MPA, however, grazing prevented the canopy phase from being reached. Instead, only mid-sized young plants were detected in autumn, but most had disappeared by winter, and those that remained had been degraded by herbivores to mere blade-less stipes with no growth meristem that eventually perish. Further research seems warranted to monitor whether this phenomenon spreads to nearby kelp beds outside the MPA. Meanwhile, restoring MPA kelp reefs will more likely require efforts to reduce herbivore activity (e.g. translocations, exclusion devices) than to bolster kelp populations. HIGHLIGHTS • Kelp canopies recurrently failed inside a MPA in recent years.• Neither propagule supply nor environmental conditions explain the failure.• Grazers keep a canopy-free state by eradicating recently recruited kelps.","PeriodicalId":12032,"journal":{"name":"European Journal of Phycology","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42535389","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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