Ecological landscape explains aquifers microbial structure.

Aquifers have significant social, economic, and ecological importance. They supply 30 % of the freshwater for human consumption worldwide, including agricultural and industrial use. Despite aquifers' importance, the relationships between aquifer categories and their inhabiting microbial communities are still unknown. Characterizing variations within microbial communities' function and taxonomy structure at different aquifers could give a panoramic view of patterns that may enable the detection and prediction of environmental impact caused by multiple sources. Using publicly available shotgun metagenomic datasets, we examined whether soil properties, land use, and climate variables would have a more significant influence on the taxonomy and functional structure of the microbial communities than the ecological landscapes of the aquifer (i.e., Karst, Porous, Saline, Geyser, and Porous Contaminated). We found that these categories are stronger predictors of microbial communities' structure than geographical localization. In addition, our results show that microbial richness and dominance patterns are the opposite of those found in multicellular life, where extreme habitats harbour richer functional and taxonomic microbial communities. We found that low-abundant and recently described candidate taxa, such as the chemolithoautotrophic genus Candidatus Altiarcheum and the Candidate phylum Parcubacteria, are the main contributors to aquifer microbial communities' dissimilarities. Genes related to gram-negative bacteria proteins, cell wall structures, and phage activity were the primary contributors to aquifer microbial communities' dissimilarities among the aquifers' ecological landscapes. The results reported in the present study highlight the utility of using ecological landscapes for investigating aquifer microbial communities. In addition, we suggest that functions played by recently described and low abundant bacterial groups need further investigation once they might affect water quality, geochemical cycles, and the effects of anthropogenic disturbances such as pollution and climatic events on aquifers.

Dynamics of coral reef benthic assemblages of the Abrolhos Bank, eastern Brazil: inferences on natural and anthropogenic drivers.

The Abrolhos Bank (eastern Brazil) encompasses the largest and richest coral reefs of the South Atlantic. Coral reef benthic assemblages of the region were monitored from 2003 to 2008. Two habitats (pinnacles' tops and walls) were sampled per site with 3-10 sites sampled within different reef areas. Different methodologies were applied in two distinct sampling periods: 2003-2005 and 2006-2008. Spatial coverage and taxonomic resolution were lower in the former than in the latter period. Benthic assemblages differed markedly in the smallest spatial scale, with greater differences recorded between habitats. Management regimes and biomass of fish functional groups (roving and territorial herbivores) had minor influences on benthic assemblages. These results suggest that local environmental factors such as light, depth and substrate inclination exert a stronger influence on the structure of benthic assemblages than protection from fishing. Reef walls of unprotected coastal reefs showed highest coral cover values, with a major contribution of Montastraea cavernosa (a sediment resistant species that may benefit from low light levels). An overall negative relationship between fleshy macroalgae and slow-growing reef-building organisms (i.e. scleractinians and crustose calcareous algae) was recorded, suggesting competition between these organisms. The opposite trend (i.e. positive relationships) was recorded for turf algae and the two reef-building organisms, suggesting beneficial interactions and/or co-occurrence mediated by unexplored factors. Turf algae cover increased across the region between 2006 and 2008, while scleractinian cover showed no change. The need of a continued and standardized monitoring program, aimed at understanding drivers of change in community patterns, as well as to subsidize sound adaptive conservation and management measures, is highlighted.

Live coral predation by parrotfishes (Perciformes: Scaridae) in the Abrolhos Bank, eastern Brazil, with comments on the classification of species into functional groups

Parrotfishes (Perciformes: Scaridae) represent a critical functional group on coral reefs because their intense herbivory activity helps in avoiding coral overgrowth by algae. Although feeding preferentially on algae and detritus, some parrotfish species also consume live corals, leading to detrimental effects that may offset the benefits of removing competitive seaweeds. Parrotfish species differ markedly in terms of jaw morphology, foraging activity and extent of substratum excavation, and are typically divided into three functional groups: browsers, scrapers and excavators. The recognition of species within each functional group helps to understand their relative effects in terms of bioerosion, coral fitness and survival, habitat alteration and ecosystem dynamics. Here we report on live coral predation by the Brazilian endemic parrotfishes Scarus trispinosus and Sparisoma amplum in the largest coral reefs of the South Atlantic (Abrolhos Bank, eastern Brazil) and comment on their classification into functional groups based on direct behavioral observations. Scarus trispinosus and Sp. amplum allocated 0.8 percent and 8.1 percent of their bites to live corals respectively. Sparisoma amplum fed at lower rates, took shorter feeding forays and larger bites than Sc. trispinosus. Bite rates and foray size were negatively correlated to body size for Sc. trispinosus, but not for Sp. amplum. Our results indicate that Sp. amplum may be primarily recognized as an excavating species, as well as the most specialized parrotfish coral predator in Brazil, while Sc. trispinosus may be recognized as a scraper or excavator depending on its body size. This functional classification corresponds to the classification used for the putative sister taxa of Sc. trispinosus (Sc. coeruleus) and the sister taxa of Sp. amplum (Sp. viride) in the Caribbean, indicating that these two congeneric species pairs play similar ecological roles in different geographic regions.

Os budiões (Perciformes: Scaridae) representam um grupo funcional crítico em recifes de corais uma vez que a intensa atividade de herbivoria que desempenham ajuda a evitar a exclusão de corais por algas. Apesar de alimentarem-se preferencialmente de algas e detrito, algumas espécies de budiões também consomem corais vivos, causando efeitos negativos aos corais, os quais podem superar os benefícios decorrentes da remoção de algas. As espécies de budiões diferem acentuadamente em sua morfologia bucal, atividade de forrageio e potencial de escavação do substrato, sendo tipicamente divididas em três grupos funcionais: podadores, raspadores e escavadores. O reconhecimento das espécies nesses grupos funcionais ajuda a entender seus efeitos relativos em termos de bioerosão, condição e sobrevivência de corais, alteração do hábitat e dinâmica do ecossistema. No presente estudo nós registramos a predação de corais vivos pelos budiões endêmicos do Brasil Scarus trispinosus e Sparisoma amplum no maior complexo coralíneo do Atlântico Sul (Banco dos Abrolhos, leste do Brasil) e comentamos sobre a classificação dessas espécies em grupos funcionais com base em observações comportamentais. Scarus trispinosus e Sp. amplum alocaram 0.8 por cento e 8.1 por cento de suas mordidas a corais vivos respectivamente. Sparisoma amplum apresentou menores taxas alimentares, menor número de mordidas em seqüência e maior tamanho de mordidas que Sc. trispinosus. A taxa de mordidas e o número de mordidas em seqüência correlacionaram-se negativamente com o tamanho corporal para Sc. trispinosus, mas não para Sp. amplum. Nossos resultados indicam que Sp. amplum pode ser reconhecida como uma espécie primariamente escavadora, além do mais especializado budião predador de corais no Brasil, ao passo que Sc. trispinosus pode ser reconhecida como uma espécie raspadora ou escavadora, dependendo de seu tamanho corporal. Essa classificação funcional é similar àquela aplicada a suposta...

Live coral predation by parrotfishes (Perciformes: Scaridae) in the Abrolhos Bank, eastern Brazil, with comments on the classification of species into functional groups

Parrotfishes (Perciformes: Scaridae) represent a critical functional group on coral reefs because their intense herbivory activity helps in avoiding coral overgrowth by algae. Although feeding preferentially on algae and detritus, some parrotfish species also consume live corals, leading to detrimental effects that may offset the benefits of removing competitive seaweeds. Parrotfish species differ markedly in terms of jaw morphology, foraging activity and extent of substratum excavation, and are typically divided into three functional groups: browsers, scrapers and excavators. The recognition of species within each functional group helps to understand their relative effects in terms of bioerosion, coral fitness and survival, habitat alteration and ecosystem dynamics. Here we report on live coral predation by the Brazilian endemic parrotfishes Scarus trispinosus and Sparisoma amplum in the largest coral reefs of the South Atlantic (Abrolhos Bank, eastern Brazil) and comment on their classification into functional groups based on direct behavioral observations. Scarus trispinosus and Sp. amplum allocated 0.8 percent and 8.1 percent of their bites to live corals respectively. Sparisoma amplum fed at lower rates, took shorter feeding forays and larger bites than Sc. trispinosus. Bite rates and foray size were negatively correlated to body size for Sc. trispinosus, but not for Sp. amplum. Our results indicate that Sp. amplum may be primarily recognized as an excavating species, as well as the most specialized parrotfish coral predator in Brazil, while Sc. trispinosus may be recognized as a scraper or excavator depending on its body size. This functional classification corresponds to the classification used for the putative sister taxa of Sc. trispinosus (Sc. coeruleus) and the sister taxa of Sp. amplum (Sp. viride) in the Caribbean, indicating that these two congeneric species pairs play similar ecological roles in different geographic regions.(AU)

Os budiões (Perciformes: Scaridae) representam um grupo funcional crítico em recifes de corais uma vez que a intensa atividade de herbivoria que desempenham ajuda a evitar a exclusão de corais por algas. Apesar de alimentarem-se preferencialmente de algas e detrito, algumas espécies de budiões também consomem corais vivos, causando efeitos negativos aos corais, os quais podem superar os benefícios decorrentes da remoção de algas. As espécies de budiões diferem acentuadamente em sua morfologia bucal, atividade de forrageio e potencial de escavação do substrato, sendo tipicamente divididas em três grupos funcionais: podadores, raspadores e escavadores. O reconhecimento das espécies nesses grupos funcionais ajuda a entender seus efeitos relativos em termos de bioerosão, condição e sobrevivência de corais, alteração do hábitat e dinâmica do ecossistema. No presente estudo nós registramos a predação de corais vivos pelos budiões endêmicos do Brasil Scarus trispinosus e Sparisoma amplum no maior complexo coralíneo do Atlântico Sul (Banco dos Abrolhos, leste do Brasil) e comentamos sobre a classificação dessas espécies em grupos funcionais com base em observações comportamentais. Scarus trispinosus e Sp. amplum alocaram 0.8 por cento e 8.1 por cento de suas mordidas a corais vivos respectivamente. Sparisoma amplum apresentou menores taxas alimentares, menor número de mordidas em seqüência e maior tamanho de mordidas que Sc. trispinosus. A taxa de mordidas e o número de mordidas em seqüência correlacionaram-se negativamente com o tamanho corporal para Sc. trispinosus, mas não para Sp. amplum. Nossos resultados indicam que Sp. amplum pode ser reconhecida como uma espécie primariamente escavadora, além do mais especializado budião predador de corais no Brasil, ao passo que Sc. trispinosus pode ser reconhecida como uma espécie raspadora ou escavadora, dependendo de seu tamanho corporal. Essa classificação funcional é similar àquela aplicada a suposta...(AU)