4 research outputs found

    The State of Knowledge of CCA Diversity in the Caribbean Coral Reefs

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    Crustose coralline algae (CCA) are a diverse and ecologically important species found in most of the world’s oceans. The current lack of taxonomic knowledge and relative abundance compromises our ability to predict species diversity numbers and, thus, their ecological roles and impacts on coral reefs. To gather a better understanding of the state of knowledge of crustose coralline algae taxonomy in the Caribbean, 107 different research papers, and other primary and secondary literature were studied; any source with taxonomical information, species identification, or genetic markers for identification was recorded. All Genebank codes were collected and sorted by supposed species marker and then ran through the National Center of Biotechnology Information. The location these genetic markers were gathered from was compared to the natural habitat range of the species, based on the Algaebank habitat description. Of the supposed 83 described species of crustose algae in the Caribbean, based on morphological characteristics, only 24 total were confirmed by DNA markers. This leaves at least 59 species of CCA to be confirmed in the Caribbean Sea with molecular markers. This indicates the importance of DNA barcode survey studies to assess the accurate diversity of this group in the region. With this limited knowledge apparent, it should be seen that a CCAs phylogenetic and taxonomical review must be done. An in-depth assessment should be conducted on CCA collections to identify the Caribbean species correctly and thus know their biodiversity in local habitats

    Molecular phylogeny and diversity of the genus Hypnea (Gigartinales, Rhodophyta) from the Brasilian coast.

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    O presente trabalho utiliza marcadores moleculares para auxiliar na caracterização e filogenia das espécies de macroalgas vermelhas do gênero Hypnea na costa do Brasil. O gênero Hypnea Lamouroux (1813) apresenta cerca de 67 espécies descritas e possui distribuição geográfica em águas quentes ao redor do mundo. Além disso, o gênero possui grande importância econômica e ecológica, como fonte de alimento e produção industrial de carragenana. Porém, a identificação das espécies de Hypnea com base exclusivamente em dados morfológicos é dificultada em virtude da plasticidade fenotípica presente no grupo, de sua morfologia relativamente simples e da ampla distribuição geográfica de suas espécies. Em vista disso, utilizamos a técnica de \"DNA barcoding\" que permite a análise de um grande número de amostras. Neste trabalho foram utilizados dois \"DNA barcodes\" (a região 5\' do gene mitocondrial cox1 e o \"universal plastid amplicon\" UPA), e para as análises filogenéticas foi utilizado o gene plastidial rbcL. Além disso, estudos morfológicos foram feitos a fim de delimitar o real valor dos caracteres morfo-anatômicos citados na literatura para a separação de espécies do gênero Hypnea. Ao todo, foram obtidas 230 amostras brasileiras de Hypnea, provenientes de 11 estados brasileiros, e 10 amostras de outros países. Um total de 367 sequências de marcadores moleculares foi obtido neste trabalho. Confirmamos a ocorrência de nove espécies para o gênero: H. cervicornis, \"H. flexicaulis\", \"H. musciformis\", H. spinella, \"H. stellulifera\", Hypnea sp. 1, Hypnea sp. 2, Hypnea sp. 3 e Hypnea sp. 4. As amostras coletadas e previamente identificadas em campo como H. cornuta revelaram-se, pelos estudos da biologia molecular, serem \"H. stellulifera\". As espécies H. musciformis, H. nigrescens, H. valentiae foram consideradas variações morfológicas de uma mesma espécie, denominada de \"H. musciformis\". A identificação das espécies com base apenas em características morfológicas mostrou-se insatisfatória, devido principalmente a plasticidade fenotípica presente no grupo, além da existência de espécies com morfologias convergentes. A técnica de \"DNA barcode\", principalmente com relação ao marcador cox1, mostrou-se essencial na identificação e delimitação das espécies, revelando cenários que passariam despercebidos com o uso apenas da morfologiaThis study uses molecular markers to aid in the characterization and phylogeny of species of the genus Hypnea, a red macroalgae, on the coast of Brazil. The genus Hypnea Lamouroux (1813) presents about 67 described species and has geographical distribution in warm waters around the world. Furthermore, the genus has great economic and ecological importance as a source of food and industrial production of carrageenan. However, the identification of the species of Hypnea based solely on morphological data is difficult due to phenotypic plasticity present in this group, its relatively simple morphology and broad geographical distribution of its species. In view of this, we use the technique of \"DNA barcoding\" that allows the analysis of a large number of samples. In this work we used two \"DNA barcodes\" (the 5 \'region of the mitochondrial gene cox1 and universal plastid amplicon UPA), and for phylogenetic analysis the plastid gene rbcL was used. In addition, morphological studies were made in order to delimit the actual value of morpho-anatomical caracters cited in the literature for the separation of species of Hypnea. Altogether, 230 Hypnea samples were obtained from 11 Brazilian states, and 10 samples from other countries. A total of 367 sequences of molecular markers were obtained in this study. We confirm the occurrence of nine species of the genus: H. cervicornis, \"H. flexicaulis\", \"H. musciformis\", \"H. spinella, \"H. stellulifera\", Hypnea sp. 1, Hypnea sp. 2, Hypnea sp. 3 and Hypnea sp. 4. Samples collected in the field and previously identified as H. cornuta based on molecular data, proved to be \"H. stellulifera\". The species H. musciformis, H. nigrescens and H. valentiae were considered morphological variations of the same species, named \"H. musciformis\". The identification of species based on morphological characteristics proved unsatisfactory, mainly due to phenotypic plasticity in this group and the existence of species with convergent morphologies. The technique of \"DNA barcode\", especially with respect to cox1 marker, was essential for the identification and definition of species, revealing scenarios that would go unnoticed by using only morpholog

    Update of the Brazilian floristic list of Algae and Cyanobacteria

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    Abstract An updated synthesis of cyanobacteria and algae information is presented for Brazil aiming to refine the data gathered to date and evaluate the progress of the biodiversity knowledge about these organisms in the country since the publication of the Catálogo de Plantas e Fungos do Brasil. The results of 2015 showed an increase of 1,250 species (35.7%) when compared to 2010, reaching a total of 4,747 species. The most diverse classes in species number were the Bacillariophyceae, Conjugatophyceae, Florideophyceae, Cyanophyceae, Dinophyceae and Euglenophyceae. Bacillariophyceae and Cyanophyceae had the highest increase in species number in the five-year interval. The Southeast and South regions were the most diverse, however, the Northeast, with the states of Piauí and Sergipe, and the Central-west region, with Mato Grosso, Goiás and Distrito Federal, also stood out in the national algal biodiversity scenario. Despite the shortage of taxonomists and limited infrastructure, the results showed a significant improvement in the knowledge regarding the diversity of cyanobacteria and algae in the country during the study period, starting to even out regional geographical differences caused by subsampling
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