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Mariana C. Oliveira - One of the best experts on this subject based on the ideXlab platform.

  • Concise review of the genus Hypnea J.V.Lamouroux, 1813
    Journal of Applied Phycology, 2020
    Co-Authors: Nair S. Yokoya, Fabio Nauer, Mariana C. Oliveira
    Abstract:

    The genus Hypnea (Rhodophyta, Gigartinales) has currently 61 accepted species distributed in tropical, subtropical, and temperate regions, growing in different habitats with a wide range of environmental factors and interactions with abiotic and biotic factors. Some Hypnea species are consumed by humans mostly in Asian and Indo-Pacific countries and are also exploited as raw material for kappa-carrageenan production, consequently, have been harvested and/or cultivated in several countries for decades. Hypnea musciformis has the widest geographical distribution around the world and it is the most studied species. However, more molecular studies on H. musciformis from different countries are necessary to understand the phenotypic plasticity and to reveal cryptic species. The present review is a compilation of information on taxonomy, morphology, anatomy, life history, distribution, ecology, physiology, cultivation and harvesting, chemical composition, and biotechnological applications. Although Hypnea species are well known as sources of carrageenans, reports on chemical diversity and biological activities highlight their remarkable potential for biotechnological applications.

  • Phylogenetic relationships within the genus Hypnea (Cystocloniaceae, Rhodophyta): convergent evolution and its implications in the infrageneric classification
    Botanica Marina, 2019
    Co-Authors: Priscila Barreto De Jesus, Fabio Nauer, Valeria Cassano, Mariana C. Oliveira, Goia De Mattos Lyra, José Marcos De Castro Nunes, Valter Loureiro De Araujo, Igor Araújo Santos De Carvalho, Alessandra Selbach Schnadelbach
    Abstract:

    Hypnea is a monophyletic genus with a complex nomenclatural and taxonomic history, and is an important commercial source of carrageenan. Phylogenies of this genus have been accessed based primarily on Asian species; however, recent studies performed in South America revealed a great diversity of species, for which phylogenetic relationships need to be evaluated. Three infrageneric sections are recognized in the genus: Pulvinatae, Spinuligerae, and Virgatae; however, morphological and molecular circumscriptions within each section lack clarity. In this study, we analyzed three distinct markers to establish phylogenetic relationships among Hypnea species. To assign each species to the correct section, morphological data were obtained from original descriptions, reference literature, and comparisons with type/topotype and herbaria specimens. Our analyses recovered robust phylogenies for the genus and provided new insights on the taxonomic status and relationships among and within Hypnea species. The combination of three genetic markers increased the resolution and support, resulting in the largest and best-resolved phylogeny of the genus to date. Single and combined analyses revealed that the three sections of the genus Hypnea are taxonomically irrelevant, as currently recognized. Morphological differences are not associated with monophyletic groups and similarities among clades could be better explained by convergent evolution in thallus habit.

  • A taxonomic review of the genus Hypnea (Gigartinales, Rhodophyta) in Brazil based on DNA barcode and morphology
    Brazilian Journal of Botany, 2019
    Co-Authors: Fabio Nauer, Priscila B. Jesus, José Marcos C. Nunes, Alessandra Selbach Schnadelbach, Valeria Cassano, Mariana C. Oliveira
    Abstract:

    The red algal genus Hypnea has a wide geographical distribution along the coast of Brazil, where it has economic and ecological importance. The relatively simple and plastic morphology, often influenced by the conditions of its habitat, complicates the identification of Hypnea species. In the past years, several studies dealing with the taxonomy of Hypnea on the coast of Brazil have changed considerably the known diversity of species in the region. Studies using molecular markers led to the description of new species, while other names were placed in synonymy. In this review, revaluation of the morphology and the addition of new sequences for COI-5P, UPA and rbc L-3P markers were used in order to better understand the diversity of Hypnea species and their range of distribution. An identification key is presented for eleven species of the genus Hypnea occurring on the coast of Brazil: H. brasiliensis P.B. Jesus, Nauer & J.M.C. Nunes, H. cervicornis J. Agardh, H. cornuta (Kützing) J. Agardh, H. cryptica P.B. Jesus & J.M.C. Nunes, H. edeniana Nauer, Cassano & M.C. Oliveira, H. flava Nauer, Cassano & M.C. Oliveira, H. pseudomusciformis Nauer, Cassano & M.C. Oliveira, H. platyclada P.B. Jesus & J.M.C. Nunes, H. spinella (C. Agardh) Kützing, H. yokoyana Nauer, Cassano & M.C. Oliveira and H. wynnei Nauer, Cassano & M.C. Oliveira. Of all taxonomic characteristics proposed by earlier studies, the only ones that have taxonomic value considering the species analyzed in this work were: (1) habit of the thallus, (2) main axis, (3) apex shape, (4) form of the branchlets and (5) tetrasporangial sori position in the branches. However, the identification of the species based only on morphological characteristics should be made with caution, once phenotypic plasticity and convergent morphologies are present in the group. The DNA barcode technique, especially the COI-5P marker, proved to be very effective in the identification and delimitation of the species, revealing scenarios that would go unnoticed by morphology alone.

  • Description of two new Caribbean species from the Hypnea musciformis complex (Cystocloniaceae, Rhodophyta)
    Phytotaxa, 2019
    Co-Authors: Fabio Nauer, Valeria Cassano, Mariana C. Oliveira
    Abstract:

    Hypnea musciformis is a red macroalgal species with economic importance as a source for production of carrageenan. Recent phylogeographic studies revealed a hidden diversity of cryptic species, putting in check its cosmopolitan distribution. The DNA barcode marker COI-5P and plastid rbc L, in addition to morphological studies, were used to investigate the species in this complex and to compare them with specimens from other countries including the type locality in Italy. The divergences between sequences within the H. musciformis complex were significantly high for both markers. Based on these analyses two new species are described, Hypnea caraibica Nauer, Cassano & M.C. Oliveira sp. nov. and Hypnea schneideri Nauer, Cassano & M.C. Oliveira sp. nov. Hypnea caraibica seems to be a common, widespread species in the Gulf of Mexico and the Caribbean and was recently introduced into Hawaii. This species was unnoticed due to lack of phylogeographic studies in the region. Hypnea schneideri seems to be more geographically restricted, but further surveys are needed to understand the distribution of this species. Because the identification of Hypnea species is complicated by their relatively simple and plastic morphology, DNA barcoding surveys and other molecular studies are essential to uncover hidden biodiversity in the genus and to supplement traditional studies based on morphology.

  • Phylogeography of the Hypnea musciformis species complex (Gigartinales, Rhodophyta) with the recognition of cryptic species in the western Atlantic Ocean
    Journal of phycology, 2019
    Co-Authors: Fabio Nauer, Carlos Frederico D. Gurgel, Lígia M. Ayres-ostrock, Estela M. Plastino, Mariana C. Oliveira
    Abstract:

    Populations of the marine benthic red macroalgae Hypnea musciformis and Hypnea pseudomusciformis along the Atlantic and Pacific Oceans were tested for phylogeographic structure using the DNA barcode COI-5P combined with rbcL for the construction of the phylogenetic tree. Strong patterns of genetic structure were detected across 210 COI-5P DNA sequences, and 37 COI-5P haplotypes were found, using multiple statistical approaches. Hypnea musciformis was found in the Northeast and Northwest Atlantic, the Mediterrean Sea, Namibia, and along the Pacific coast of Mexico. Two new putative species were detected, Hypnea sp. 1 in the Caribbean Sea and Hypnea sp. 2 in the Dominican Republic. Three distinct marine phylogeographic provinces were recognized in the Southern Hemisphere for H. pseudomusciformis: Uruguay, South-Southeast Brazil, and Northeast Brazil. The degree of genetic isolation and distinctness among these provinces varied considerably. The Uruguay province was the most genetically distinct, as characterized by four unique haplotypes not shared with any of the Brazilian populations. Statistically significant results support both, isolation by distance and isolation by environment hypotheses, explaining the formation and mantainance of phylogeographic structuring along the Uruguay-Brazil coast. Geographic, taxonomic and molecular marker concordances were found between our H. pseudomusciformis results and published studies. Furthermore, our data indicate that the Hawaiian introduced populations of H. musciformis contain Hypnea sp. 1 haplotypes, the current known distribution of which is restricted to the Caribbean.

Fabio Nauer - One of the best experts on this subject based on the ideXlab platform.

  • Concise review of the genus Hypnea J.V.Lamouroux, 1813
    Journal of Applied Phycology, 2020
    Co-Authors: Nair S. Yokoya, Fabio Nauer, Mariana C. Oliveira
    Abstract:

    The genus Hypnea (Rhodophyta, Gigartinales) has currently 61 accepted species distributed in tropical, subtropical, and temperate regions, growing in different habitats with a wide range of environmental factors and interactions with abiotic and biotic factors. Some Hypnea species are consumed by humans mostly in Asian and Indo-Pacific countries and are also exploited as raw material for kappa-carrageenan production, consequently, have been harvested and/or cultivated in several countries for decades. Hypnea musciformis has the widest geographical distribution around the world and it is the most studied species. However, more molecular studies on H. musciformis from different countries are necessary to understand the phenotypic plasticity and to reveal cryptic species. The present review is a compilation of information on taxonomy, morphology, anatomy, life history, distribution, ecology, physiology, cultivation and harvesting, chemical composition, and biotechnological applications. Although Hypnea species are well known as sources of carrageenans, reports on chemical diversity and biological activities highlight their remarkable potential for biotechnological applications.

  • Phylogenetic relationships within the genus Hypnea (Cystocloniaceae, Rhodophyta): convergent evolution and its implications in the infrageneric classification
    Botanica Marina, 2019
    Co-Authors: Priscila Barreto De Jesus, Fabio Nauer, Valeria Cassano, Mariana C. Oliveira, Goia De Mattos Lyra, José Marcos De Castro Nunes, Valter Loureiro De Araujo, Igor Araújo Santos De Carvalho, Alessandra Selbach Schnadelbach
    Abstract:

    Hypnea is a monophyletic genus with a complex nomenclatural and taxonomic history, and is an important commercial source of carrageenan. Phylogenies of this genus have been accessed based primarily on Asian species; however, recent studies performed in South America revealed a great diversity of species, for which phylogenetic relationships need to be evaluated. Three infrageneric sections are recognized in the genus: Pulvinatae, Spinuligerae, and Virgatae; however, morphological and molecular circumscriptions within each section lack clarity. In this study, we analyzed three distinct markers to establish phylogenetic relationships among Hypnea species. To assign each species to the correct section, morphological data were obtained from original descriptions, reference literature, and comparisons with type/topotype and herbaria specimens. Our analyses recovered robust phylogenies for the genus and provided new insights on the taxonomic status and relationships among and within Hypnea species. The combination of three genetic markers increased the resolution and support, resulting in the largest and best-resolved phylogeny of the genus to date. Single and combined analyses revealed that the three sections of the genus Hypnea are taxonomically irrelevant, as currently recognized. Morphological differences are not associated with monophyletic groups and similarities among clades could be better explained by convergent evolution in thallus habit.

  • A taxonomic review of the genus Hypnea (Gigartinales, Rhodophyta) in Brazil based on DNA barcode and morphology
    Brazilian Journal of Botany, 2019
    Co-Authors: Fabio Nauer, Priscila B. Jesus, José Marcos C. Nunes, Alessandra Selbach Schnadelbach, Valeria Cassano, Mariana C. Oliveira
    Abstract:

    The red algal genus Hypnea has a wide geographical distribution along the coast of Brazil, where it has economic and ecological importance. The relatively simple and plastic morphology, often influenced by the conditions of its habitat, complicates the identification of Hypnea species. In the past years, several studies dealing with the taxonomy of Hypnea on the coast of Brazil have changed considerably the known diversity of species in the region. Studies using molecular markers led to the description of new species, while other names were placed in synonymy. In this review, revaluation of the morphology and the addition of new sequences for COI-5P, UPA and rbc L-3P markers were used in order to better understand the diversity of Hypnea species and their range of distribution. An identification key is presented for eleven species of the genus Hypnea occurring on the coast of Brazil: H. brasiliensis P.B. Jesus, Nauer & J.M.C. Nunes, H. cervicornis J. Agardh, H. cornuta (Kützing) J. Agardh, H. cryptica P.B. Jesus & J.M.C. Nunes, H. edeniana Nauer, Cassano & M.C. Oliveira, H. flava Nauer, Cassano & M.C. Oliveira, H. pseudomusciformis Nauer, Cassano & M.C. Oliveira, H. platyclada P.B. Jesus & J.M.C. Nunes, H. spinella (C. Agardh) Kützing, H. yokoyana Nauer, Cassano & M.C. Oliveira and H. wynnei Nauer, Cassano & M.C. Oliveira. Of all taxonomic characteristics proposed by earlier studies, the only ones that have taxonomic value considering the species analyzed in this work were: (1) habit of the thallus, (2) main axis, (3) apex shape, (4) form of the branchlets and (5) tetrasporangial sori position in the branches. However, the identification of the species based only on morphological characteristics should be made with caution, once phenotypic plasticity and convergent morphologies are present in the group. The DNA barcode technique, especially the COI-5P marker, proved to be very effective in the identification and delimitation of the species, revealing scenarios that would go unnoticed by morphology alone.

  • Description of two new Caribbean species from the Hypnea musciformis complex (Cystocloniaceae, Rhodophyta)
    Phytotaxa, 2019
    Co-Authors: Fabio Nauer, Valeria Cassano, Mariana C. Oliveira
    Abstract:

    Hypnea musciformis is a red macroalgal species with economic importance as a source for production of carrageenan. Recent phylogeographic studies revealed a hidden diversity of cryptic species, putting in check its cosmopolitan distribution. The DNA barcode marker COI-5P and plastid rbc L, in addition to morphological studies, were used to investigate the species in this complex and to compare them with specimens from other countries including the type locality in Italy. The divergences between sequences within the H. musciformis complex were significantly high for both markers. Based on these analyses two new species are described, Hypnea caraibica Nauer, Cassano & M.C. Oliveira sp. nov. and Hypnea schneideri Nauer, Cassano & M.C. Oliveira sp. nov. Hypnea caraibica seems to be a common, widespread species in the Gulf of Mexico and the Caribbean and was recently introduced into Hawaii. This species was unnoticed due to lack of phylogeographic studies in the region. Hypnea schneideri seems to be more geographically restricted, but further surveys are needed to understand the distribution of this species. Because the identification of Hypnea species is complicated by their relatively simple and plastic morphology, DNA barcoding surveys and other molecular studies are essential to uncover hidden biodiversity in the genus and to supplement traditional studies based on morphology.

  • Phylogeography of the Hypnea musciformis species complex (Gigartinales, Rhodophyta) with the recognition of cryptic species in the western Atlantic Ocean
    Journal of phycology, 2019
    Co-Authors: Fabio Nauer, Carlos Frederico D. Gurgel, Lígia M. Ayres-ostrock, Estela M. Plastino, Mariana C. Oliveira
    Abstract:

    Populations of the marine benthic red macroalgae Hypnea musciformis and Hypnea pseudomusciformis along the Atlantic and Pacific Oceans were tested for phylogeographic structure using the DNA barcode COI-5P combined with rbcL for the construction of the phylogenetic tree. Strong patterns of genetic structure were detected across 210 COI-5P DNA sequences, and 37 COI-5P haplotypes were found, using multiple statistical approaches. Hypnea musciformis was found in the Northeast and Northwest Atlantic, the Mediterrean Sea, Namibia, and along the Pacific coast of Mexico. Two new putative species were detected, Hypnea sp. 1 in the Caribbean Sea and Hypnea sp. 2 in the Dominican Republic. Three distinct marine phylogeographic provinces were recognized in the Southern Hemisphere for H. pseudomusciformis: Uruguay, South-Southeast Brazil, and Northeast Brazil. The degree of genetic isolation and distinctness among these provinces varied considerably. The Uruguay province was the most genetically distinct, as characterized by four unique haplotypes not shared with any of the Brazilian populations. Statistically significant results support both, isolation by distance and isolation by environment hypotheses, explaining the formation and mantainance of phylogeographic structuring along the Uruguay-Brazil coast. Geographic, taxonomic and molecular marker concordances were found between our H. pseudomusciformis results and published studies. Furthermore, our data indicate that the Hawaiian introduced populations of H. musciformis contain Hypnea sp. 1 haplotypes, the current known distribution of which is restricted to the Caribbean.

Priscila Barreto De Jesus - One of the best experts on this subject based on the ideXlab platform.

  • Phylogenetic relationships within the genus Hypnea (Cystocloniaceae, Rhodophyta): convergent evolution and its implications in the infrageneric classification
    Botanica Marina, 2019
    Co-Authors: Priscila Barreto De Jesus, Fabio Nauer, Valeria Cassano, Mariana C. Oliveira, Goia De Mattos Lyra, José Marcos De Castro Nunes, Valter Loureiro De Araujo, Igor Araújo Santos De Carvalho, Alessandra Selbach Schnadelbach
    Abstract:

    Hypnea is a monophyletic genus with a complex nomenclatural and taxonomic history, and is an important commercial source of carrageenan. Phylogenies of this genus have been accessed based primarily on Asian species; however, recent studies performed in South America revealed a great diversity of species, for which phylogenetic relationships need to be evaluated. Three infrageneric sections are recognized in the genus: Pulvinatae, Spinuligerae, and Virgatae; however, morphological and molecular circumscriptions within each section lack clarity. In this study, we analyzed three distinct markers to establish phylogenetic relationships among Hypnea species. To assign each species to the correct section, morphological data were obtained from original descriptions, reference literature, and comparisons with type/topotype and herbaria specimens. Our analyses recovered robust phylogenies for the genus and provided new insights on the taxonomic status and relationships among and within Hypnea species. The combination of three genetic markers increased the resolution and support, resulting in the largest and best-resolved phylogeny of the genus to date. Single and combined analyses revealed that the three sections of the genus Hypnea are taxonomically irrelevant, as currently recognized. Morphological differences are not associated with monophyletic groups and similarities among clades could be better explained by convergent evolution in thallus habit.

  • Species‐delimitation and phylogenetic analyses of some cosmopolitan species of Hypnea (Rhodophyta) reveal synonyms and misapplied names to H. cervicornis, including a new species from Brazil
    Journal of phycology, 2016
    Co-Authors: Priscila Barreto De Jesus, Fabio Nauer, Valeria Cassano, Mariana C. Oliveira, Goia De Mattos Lyra, José Marcos De Castro Nunes, Alessandra Selbach Schnadelbach
    Abstract:

    Hypnea has an intricate nomenclatural history due to a wide pantropical distribution and considerable morphological variation. Recent molecular studies have provided further clarification on the systematics of the genus; however, species of uncertain affinities remain due to flawed taxonomic identification. Detailed analyses coupled with literature review indicated a strong relationship among H. aspera, H. cervicornis, H. flexicaulis, and H. tenuis, suggesting a need for further taxonomic studies. Here, we analyzed sequences from two molecular markers (COI-5P and rbcL) and performed several DNA-based delimitation methods (mBGD, ABGD, SPN, PTP and GMYC). These molecular approaches were contrasted with morphological and phylogenetic evidence from type specimens and/or topotype collections of related species under a conservative approach. Our results demonstrate that H. aspera and H. flexicaulis represent heterotypic synonyms of H. cervicornis and indicate the existence of a misidentified Hypnea species, widely distributed on the Brazilian coast, described here as a new species: H. brasiliensis. Finally, inconsistencies observed among our results based on six different species delimitation methods evidence the need for adequate sampling and marker choice for different methods.

  • species delimitation and phylogenetic analyses of some cosmopolitan species of Hypnea rhodophyta reveal synonyms and misapplied names to h cervicornis including a new species from brazil
    Journal of Phycology, 2016
    Co-Authors: Fabio Nauer, Valeria Cassano, Mariana C. Oliveira, Priscila Barreto De Jesus, Goia De Mattos Lyra, José Marcos De Castro Nunes, Alessandra Selbach Schnadelbach
    Abstract:

    Hypnea has an intricate nomenclatural history due to a wide pantropical distribution and considerable morphological variation. Recent molecular studies have provided further clarification on the systematics of the genus; however, species of uncertain affinities remain due to flawed taxonomic identification. Detailed analyses coupled with literature review indicated a strong relationship among H. aspera, H. cervicornis, H. flexicaulis, and H. tenuis, suggesting a need for further taxonomic studies. Here, we analyzed sequences from two molecular markers (COI-5P and rbcL) and performed several DNA-based delimitation methods (mBGD, ABGD, SPN, PTP and GMYC). These molecular approaches were contrasted with morphological and phylogenetic evidence from type specimens and/or topotype collections of related species under a conservative approach. Our results demonstrate that H. aspera and H. flexicaulis represent heterotypic synonyms of H. cervicornis and indicate the existence of a misidentified Hypnea species, widely distributed on the Brazilian coast, described here as a new species: H. brasiliensis. Finally, inconsistencies observed among our results based on six different species delimitation methods evidence the need for adequate sampling and marker choice for different methods.

  • Extension of the distribution range of Hypnea stellulifera (Cystocloniaceae, Rhodophyta) to the South Atlantic: Morphological and molecular evidence
    Aquatic Botany, 2015
    Co-Authors: Priscila Barreto De Jesus, Mariana Santos Silva, Goia De Mattos Lyra, José Marcos De Castro Nunes, Alessandra Selbach Schnadelbach
    Abstract:

    Abstract Hypnea stellulifera was, until now, considered endemic to tropical Asia. Here, we report for the first time the expansion of its distribution to the Atlantic Ocean on the basis of collections from the northeast of Brazil. Comparison of morphological features of our specimens with Asian specimens of H. stellulifera and molecular data analysis allow us to confirm its identification. Samples analyzed in this study represent the first assessment of Hypnea sequences collected in a tropical area from South America. Among the three genes analyzed (the mitochondrial cox1 and the plastidial UPA and rbcL), UPA was the most conserved, and the cox1 was the most variable marker. Despite this, all three markers were efficient as DNA barcoding markers for Hypnea. In our phylogenetic analysis, H. stellulifera had a sister relationship with the clade that includes H. cornuta, H. musciformis, H. flagelliformis, and H. chordacea. Our results demonstrate that the analysis of Hypnea species collected at large geographic distances and/or in different tropical areas reveals a higher degree of intraspecific variation as well as decreased interspecific divergence among distinct species from closer areas. These findings corroborate the necessity of a combined analysis of morphology and different genetic markers for a better understanding of taxonomy and phylogeny of the genus Hypnea.

  • The genus Hypnea (Cystocloniaceae, Rhodophyta) on the coast of Bahia, Brazil
    SITIENTIBUS série Ciências Biológicas, 2013
    Co-Authors: Priscila Barreto De Jesus, Alessandra Selbach Schnadelbach, José Marcos De Castro Nunes
    Abstract:

    A detailed morpho-anatomical study of the genus Hypnea from the state of Bahia is presented. Eight species have been recognized: H. cenomyce , H. cervicornis , H. cornuta , H. musciformis , H. nigrescens , H. platyclada , H. spinella and H. valentiae . An identification key, as well as descriptions, illustrations, comparisons with related taxa and maps of distribution in Bahia for each species, are presented.

Valeria Cassano - One of the best experts on this subject based on the ideXlab platform.

  • Phylogenetic relationships within the genus Hypnea (Cystocloniaceae, Rhodophyta): convergent evolution and its implications in the infrageneric classification
    Botanica Marina, 2019
    Co-Authors: Priscila Barreto De Jesus, Fabio Nauer, Valeria Cassano, Mariana C. Oliveira, Goia De Mattos Lyra, José Marcos De Castro Nunes, Valter Loureiro De Araujo, Igor Araújo Santos De Carvalho, Alessandra Selbach Schnadelbach
    Abstract:

    Hypnea is a monophyletic genus with a complex nomenclatural and taxonomic history, and is an important commercial source of carrageenan. Phylogenies of this genus have been accessed based primarily on Asian species; however, recent studies performed in South America revealed a great diversity of species, for which phylogenetic relationships need to be evaluated. Three infrageneric sections are recognized in the genus: Pulvinatae, Spinuligerae, and Virgatae; however, morphological and molecular circumscriptions within each section lack clarity. In this study, we analyzed three distinct markers to establish phylogenetic relationships among Hypnea species. To assign each species to the correct section, morphological data were obtained from original descriptions, reference literature, and comparisons with type/topotype and herbaria specimens. Our analyses recovered robust phylogenies for the genus and provided new insights on the taxonomic status and relationships among and within Hypnea species. The combination of three genetic markers increased the resolution and support, resulting in the largest and best-resolved phylogeny of the genus to date. Single and combined analyses revealed that the three sections of the genus Hypnea are taxonomically irrelevant, as currently recognized. Morphological differences are not associated with monophyletic groups and similarities among clades could be better explained by convergent evolution in thallus habit.

  • A taxonomic review of the genus Hypnea (Gigartinales, Rhodophyta) in Brazil based on DNA barcode and morphology
    Brazilian Journal of Botany, 2019
    Co-Authors: Fabio Nauer, Priscila B. Jesus, José Marcos C. Nunes, Alessandra Selbach Schnadelbach, Valeria Cassano, Mariana C. Oliveira
    Abstract:

    The red algal genus Hypnea has a wide geographical distribution along the coast of Brazil, where it has economic and ecological importance. The relatively simple and plastic morphology, often influenced by the conditions of its habitat, complicates the identification of Hypnea species. In the past years, several studies dealing with the taxonomy of Hypnea on the coast of Brazil have changed considerably the known diversity of species in the region. Studies using molecular markers led to the description of new species, while other names were placed in synonymy. In this review, revaluation of the morphology and the addition of new sequences for COI-5P, UPA and rbc L-3P markers were used in order to better understand the diversity of Hypnea species and their range of distribution. An identification key is presented for eleven species of the genus Hypnea occurring on the coast of Brazil: H. brasiliensis P.B. Jesus, Nauer & J.M.C. Nunes, H. cervicornis J. Agardh, H. cornuta (Kützing) J. Agardh, H. cryptica P.B. Jesus & J.M.C. Nunes, H. edeniana Nauer, Cassano & M.C. Oliveira, H. flava Nauer, Cassano & M.C. Oliveira, H. pseudomusciformis Nauer, Cassano & M.C. Oliveira, H. platyclada P.B. Jesus & J.M.C. Nunes, H. spinella (C. Agardh) Kützing, H. yokoyana Nauer, Cassano & M.C. Oliveira and H. wynnei Nauer, Cassano & M.C. Oliveira. Of all taxonomic characteristics proposed by earlier studies, the only ones that have taxonomic value considering the species analyzed in this work were: (1) habit of the thallus, (2) main axis, (3) apex shape, (4) form of the branchlets and (5) tetrasporangial sori position in the branches. However, the identification of the species based only on morphological characteristics should be made with caution, once phenotypic plasticity and convergent morphologies are present in the group. The DNA barcode technique, especially the COI-5P marker, proved to be very effective in the identification and delimitation of the species, revealing scenarios that would go unnoticed by morphology alone.

  • Description of two new Caribbean species from the Hypnea musciformis complex (Cystocloniaceae, Rhodophyta)
    Phytotaxa, 2019
    Co-Authors: Fabio Nauer, Valeria Cassano, Mariana C. Oliveira
    Abstract:

    Hypnea musciformis is a red macroalgal species with economic importance as a source for production of carrageenan. Recent phylogeographic studies revealed a hidden diversity of cryptic species, putting in check its cosmopolitan distribution. The DNA barcode marker COI-5P and plastid rbc L, in addition to morphological studies, were used to investigate the species in this complex and to compare them with specimens from other countries including the type locality in Italy. The divergences between sequences within the H. musciformis complex were significantly high for both markers. Based on these analyses two new species are described, Hypnea caraibica Nauer, Cassano & M.C. Oliveira sp. nov. and Hypnea schneideri Nauer, Cassano & M.C. Oliveira sp. nov. Hypnea caraibica seems to be a common, widespread species in the Gulf of Mexico and the Caribbean and was recently introduced into Hawaii. This species was unnoticed due to lack of phylogeographic studies in the region. Hypnea schneideri seems to be more geographically restricted, but further surveys are needed to understand the distribution of this species. Because the identification of Hypnea species is complicated by their relatively simple and plastic morphology, DNA barcoding surveys and other molecular studies are essential to uncover hidden biodiversity in the genus and to supplement traditional studies based on morphology.

  • Species‐delimitation and phylogenetic analyses of some cosmopolitan species of Hypnea (Rhodophyta) reveal synonyms and misapplied names to H. cervicornis, including a new species from Brazil
    Journal of phycology, 2016
    Co-Authors: Priscila Barreto De Jesus, Fabio Nauer, Valeria Cassano, Mariana C. Oliveira, Goia De Mattos Lyra, José Marcos De Castro Nunes, Alessandra Selbach Schnadelbach
    Abstract:

    Hypnea has an intricate nomenclatural history due to a wide pantropical distribution and considerable morphological variation. Recent molecular studies have provided further clarification on the systematics of the genus; however, species of uncertain affinities remain due to flawed taxonomic identification. Detailed analyses coupled with literature review indicated a strong relationship among H. aspera, H. cervicornis, H. flexicaulis, and H. tenuis, suggesting a need for further taxonomic studies. Here, we analyzed sequences from two molecular markers (COI-5P and rbcL) and performed several DNA-based delimitation methods (mBGD, ABGD, SPN, PTP and GMYC). These molecular approaches were contrasted with morphological and phylogenetic evidence from type specimens and/or topotype collections of related species under a conservative approach. Our results demonstrate that H. aspera and H. flexicaulis represent heterotypic synonyms of H. cervicornis and indicate the existence of a misidentified Hypnea species, widely distributed on the Brazilian coast, described here as a new species: H. brasiliensis. Finally, inconsistencies observed among our results based on six different species delimitation methods evidence the need for adequate sampling and marker choice for different methods.

  • Hypnea wynnei and Hypnea yokoyana (Cystocloniaceae, Rhodophyta), two new species revealed by a DNA barcoding survey on the Brazilian coast
    Phytotaxa, 2016
    Co-Authors: Fabio Nauer, Valeria Cassano, Mariana C. Oliveira
    Abstract:

    Two new species of the red algal genus Hypnea (Gigartinales) are described for the southeastern coast of Brazil based on three molecular markers (COI-5P, rbc L and UPA), detailed morphological analysis, and comparison with closely related species. These species were named H . wynnei Nauer, Cassano & M.C. Oliveira and H. yokoyana Nauer, Cassano & M.C. Oliveira. Hypnea wynnei is characterized primarily by its reduced size, sub-erect tufts with few lateral branches and entangled basal portion, a thallus that is flattened only at the apical portions, and tetrasporangial sori developed only at apical portions of the branchlets. Hypnea yokoyana is characterized by its larger thallus, profuse branching, entirely terete axes, larger diameter of the main axes, and lack of entangling at its base. The molecular data support the conclusion that H. wynnei and H. yokoyana are distinct from other Hypnea species and are distantly related to Hypnea from the Brazilian coast.

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  • Phylogenetic relationships within the genus Hypnea (Cystocloniaceae, Rhodophyta): convergent evolution and its implications in the infrageneric classification
    Botanica Marina, 2019
    Co-Authors: Priscila Barreto De Jesus, Fabio Nauer, Valeria Cassano, Mariana C. Oliveira, Goia De Mattos Lyra, José Marcos De Castro Nunes, Valter Loureiro De Araujo, Igor Araújo Santos De Carvalho, Alessandra Selbach Schnadelbach
    Abstract:

    Hypnea is a monophyletic genus with a complex nomenclatural and taxonomic history, and is an important commercial source of carrageenan. Phylogenies of this genus have been accessed based primarily on Asian species; however, recent studies performed in South America revealed a great diversity of species, for which phylogenetic relationships need to be evaluated. Three infrageneric sections are recognized in the genus: Pulvinatae, Spinuligerae, and Virgatae; however, morphological and molecular circumscriptions within each section lack clarity. In this study, we analyzed three distinct markers to establish phylogenetic relationships among Hypnea species. To assign each species to the correct section, morphological data were obtained from original descriptions, reference literature, and comparisons with type/topotype and herbaria specimens. Our analyses recovered robust phylogenies for the genus and provided new insights on the taxonomic status and relationships among and within Hypnea species. The combination of three genetic markers increased the resolution and support, resulting in the largest and best-resolved phylogeny of the genus to date. Single and combined analyses revealed that the three sections of the genus Hypnea are taxonomically irrelevant, as currently recognized. Morphological differences are not associated with monophyletic groups and similarities among clades could be better explained by convergent evolution in thallus habit.

  • A taxonomic review of the genus Hypnea (Gigartinales, Rhodophyta) in Brazil based on DNA barcode and morphology
    Brazilian Journal of Botany, 2019
    Co-Authors: Fabio Nauer, Priscila B. Jesus, José Marcos C. Nunes, Alessandra Selbach Schnadelbach, Valeria Cassano, Mariana C. Oliveira
    Abstract:

    The red algal genus Hypnea has a wide geographical distribution along the coast of Brazil, where it has economic and ecological importance. The relatively simple and plastic morphology, often influenced by the conditions of its habitat, complicates the identification of Hypnea species. In the past years, several studies dealing with the taxonomy of Hypnea on the coast of Brazil have changed considerably the known diversity of species in the region. Studies using molecular markers led to the description of new species, while other names were placed in synonymy. In this review, revaluation of the morphology and the addition of new sequences for COI-5P, UPA and rbc L-3P markers were used in order to better understand the diversity of Hypnea species and their range of distribution. An identification key is presented for eleven species of the genus Hypnea occurring on the coast of Brazil: H. brasiliensis P.B. Jesus, Nauer & J.M.C. Nunes, H. cervicornis J. Agardh, H. cornuta (Kützing) J. Agardh, H. cryptica P.B. Jesus & J.M.C. Nunes, H. edeniana Nauer, Cassano & M.C. Oliveira, H. flava Nauer, Cassano & M.C. Oliveira, H. pseudomusciformis Nauer, Cassano & M.C. Oliveira, H. platyclada P.B. Jesus & J.M.C. Nunes, H. spinella (C. Agardh) Kützing, H. yokoyana Nauer, Cassano & M.C. Oliveira and H. wynnei Nauer, Cassano & M.C. Oliveira. Of all taxonomic characteristics proposed by earlier studies, the only ones that have taxonomic value considering the species analyzed in this work were: (1) habit of the thallus, (2) main axis, (3) apex shape, (4) form of the branchlets and (5) tetrasporangial sori position in the branches. However, the identification of the species based only on morphological characteristics should be made with caution, once phenotypic plasticity and convergent morphologies are present in the group. The DNA barcode technique, especially the COI-5P marker, proved to be very effective in the identification and delimitation of the species, revealing scenarios that would go unnoticed by morphology alone.

  • Species‐delimitation and phylogenetic analyses of some cosmopolitan species of Hypnea (Rhodophyta) reveal synonyms and misapplied names to H. cervicornis, including a new species from Brazil
    Journal of phycology, 2016
    Co-Authors: Priscila Barreto De Jesus, Fabio Nauer, Valeria Cassano, Mariana C. Oliveira, Goia De Mattos Lyra, José Marcos De Castro Nunes, Alessandra Selbach Schnadelbach
    Abstract:

    Hypnea has an intricate nomenclatural history due to a wide pantropical distribution and considerable morphological variation. Recent molecular studies have provided further clarification on the systematics of the genus; however, species of uncertain affinities remain due to flawed taxonomic identification. Detailed analyses coupled with literature review indicated a strong relationship among H. aspera, H. cervicornis, H. flexicaulis, and H. tenuis, suggesting a need for further taxonomic studies. Here, we analyzed sequences from two molecular markers (COI-5P and rbcL) and performed several DNA-based delimitation methods (mBGD, ABGD, SPN, PTP and GMYC). These molecular approaches were contrasted with morphological and phylogenetic evidence from type specimens and/or topotype collections of related species under a conservative approach. Our results demonstrate that H. aspera and H. flexicaulis represent heterotypic synonyms of H. cervicornis and indicate the existence of a misidentified Hypnea species, widely distributed on the Brazilian coast, described here as a new species: H. brasiliensis. Finally, inconsistencies observed among our results based on six different species delimitation methods evidence the need for adequate sampling and marker choice for different methods.

  • species delimitation and phylogenetic analyses of some cosmopolitan species of Hypnea rhodophyta reveal synonyms and misapplied names to h cervicornis including a new species from brazil
    Journal of Phycology, 2016
    Co-Authors: Fabio Nauer, Valeria Cassano, Mariana C. Oliveira, Priscila Barreto De Jesus, Goia De Mattos Lyra, José Marcos De Castro Nunes, Alessandra Selbach Schnadelbach
    Abstract:

    Hypnea has an intricate nomenclatural history due to a wide pantropical distribution and considerable morphological variation. Recent molecular studies have provided further clarification on the systematics of the genus; however, species of uncertain affinities remain due to flawed taxonomic identification. Detailed analyses coupled with literature review indicated a strong relationship among H. aspera, H. cervicornis, H. flexicaulis, and H. tenuis, suggesting a need for further taxonomic studies. Here, we analyzed sequences from two molecular markers (COI-5P and rbcL) and performed several DNA-based delimitation methods (mBGD, ABGD, SPN, PTP and GMYC). These molecular approaches were contrasted with morphological and phylogenetic evidence from type specimens and/or topotype collections of related species under a conservative approach. Our results demonstrate that H. aspera and H. flexicaulis represent heterotypic synonyms of H. cervicornis and indicate the existence of a misidentified Hypnea species, widely distributed on the Brazilian coast, described here as a new species: H. brasiliensis. Finally, inconsistencies observed among our results based on six different species delimitation methods evidence the need for adequate sampling and marker choice for different methods.

  • Extension of the distribution range of Hypnea stellulifera (Cystocloniaceae, Rhodophyta) to the South Atlantic: Morphological and molecular evidence
    Aquatic Botany, 2015
    Co-Authors: Priscila Barreto De Jesus, Mariana Santos Silva, Goia De Mattos Lyra, José Marcos De Castro Nunes, Alessandra Selbach Schnadelbach
    Abstract:

    Abstract Hypnea stellulifera was, until now, considered endemic to tropical Asia. Here, we report for the first time the expansion of its distribution to the Atlantic Ocean on the basis of collections from the northeast of Brazil. Comparison of morphological features of our specimens with Asian specimens of H. stellulifera and molecular data analysis allow us to confirm its identification. Samples analyzed in this study represent the first assessment of Hypnea sequences collected in a tropical area from South America. Among the three genes analyzed (the mitochondrial cox1 and the plastidial UPA and rbcL), UPA was the most conserved, and the cox1 was the most variable marker. Despite this, all three markers were efficient as DNA barcoding markers for Hypnea. In our phylogenetic analysis, H. stellulifera had a sister relationship with the clade that includes H. cornuta, H. musciformis, H. flagelliformis, and H. chordacea. Our results demonstrate that the analysis of Hypnea species collected at large geographic distances and/or in different tropical areas reveals a higher degree of intraspecific variation as well as decreased interspecific divergence among distinct species from closer areas. These findings corroborate the necessity of a combined analysis of morphology and different genetic markers for a better understanding of taxonomy and phylogeny of the genus Hypnea.