Ecologia trófica de peixes ocorrentes em bancos de macrófitas aquáticas na baia Caiçara, Pantanal Mato-Grossense

The present research characterized the diet of fish and determined the trophic guilds of ichthyofauna residence of aquatic macrophytes stands. The sampling were carried out through a trap with mesh size of 3mm under stands of aquatic macrophytes of two portions of bay Caiçara, Pantanal Mato-Grossense. Species diet was determined through analysis of stomach contents, using frequency of occurrence and volumetric methods, being expressed by the Alimentary Index (IAi). Only eighteen fish species, of the sixty five captured, have their diet characterized. Five species were considered herbivorous, four insectivorous, four omnivorous, three carnivorous and two detritivorous.Esta pesquisa caracterizou a dieta de peixes e determinou as guildas tróficas da ictiofauna habitante de bancos de macrófitas aquáticas. As amostragens foram realizadas através da varredura de uma armação com tela de malha de 3 mm, sob bancos de macrófitas aquáticas de duas porções da baía Caiçara, Pantanal Mato-Grossense. A dieta das espécies foi determinada através da análise do conteúdo estomacal, utilizando os métodos freqüência de ocorrência e volume, sendo expressa pelo Índice de Importância Alimentar (IAi). Das 65 espécies de peixes capturadas, apenas 18 tiveram sua dieta caracterizada. Cinco espécies foram consideradas herbívoras, quatro insetívoras, quatro onívoras, três carnívoras e duas detritívoras

A Scientometric Analysis of the Use Indices for Water Quality Biomonitoring

Water resources are supplied under strong anthropic pressures and result in several problems of water contamination in the world, which necessitates the use of methodologies for their evaluation. Thus, this research aimed to identify the biomonitoring indices based on macroinvertebrates in the evaluation of the quality of the water used and to identify its application trends. The study was developed through a scientometric review over a 20-year period (2000–2020). The search consisted of articles indexed in the Scielo, ScienceDirect, and Scopus databases, based on the keywords “biotic index” * OR “aquatic macroinvertebrates” * OR “benthic macroinvertebrates” * OR “Biomonitoring” * AND “water quality.” Selection, such as inclusion and exclusion, was applied in the Start program (State of the Art through Systematic Review-Start). The results showed that the EPT index (Ephemeroptera, Plecoptera, and Trichoptera) was the most used among all researched databases (20%), and among the Ecological Indicators journals from which the largest number of publications were obtained (11%). Regarding the indices used in biomonitoring research, the ASPT index (average score per taxon) was the only one with a tendency to increase in use over the years (R² = 0.29; p < 0.05). Although the biomonitoring indices are commonly used worldwide denoting that it is still an alternative tool, this literature review showed that among the indices only one has a trend of use, which must be considered for further research.Os recursos hídricos são abastecidos sob forte pressão antrópica e dão origem a diversos problemas de poluição hídrica no mundo, que exigem o uso de metodologias para sua avaliação. Assim, esta pesquisa teve como objetivo identificar índices de biomonitoramento baseados em macroinvertebrados na avaliação da qualidade da água utilizada e identificar suas tendências de aplicação. O estudo foi desenvolvido através de uma revisão cienciométrica durante um período de 20 anos (2000-2020). A busca consiste em artigos indexados nas bases de dados Scielo, ScienceDirect e Scopus, com base nas palavras-chave "índice biótico" * OR "macroinvertebrados aquáticos" * OR "macroinvertebrados bentônicos" * OR "Biomonitoring" * AND "qualidade da água". A seleção, assim como a inclusão e a exclusão, foi aplicada no programa Start (estado da arte por meio de revisão sistemática-start). Os resultados mostraram que o índice EPT (Ephemeroptera, Plecoptera e Trichoptera) foi o mais utilizado entre todas as bases investigadas (20%) e entre os periódicos, obteve-se o maior número de Indicadores Ecológicos (11%). Em relação aos índices utilizados nas pesquisas de biomonitoramento, o índice ASPT (pontuação média por táxon) foi o único com tendência a aumentar sua utilização ao longo dos anos (R² = 0,29; p < 0,05). Embora os índices de biomonitoramento sejam comumente usados ​​em todo o mundo, indicando que ainda é uma ferramenta alternativa, esta revisão de literatura mostra que dentre os índices apenas um apresenta tendência de uso, o que deve ser considerado para pesquisas futuras

Extending the ecological distribution of Desmonostoc genus: proposal of Desmonostoc salinum sp. nov., a novel Cyanobacteria from a saline–alkaline lake

Cyanobacteria is an ancient phylum of oxygenic photosynthetic microorganisms found in almost all environments of Earth. In recent years, the taxonomic placement of some cyanobacterial strains, including those belonging to the genus Nostoc sensu lato, have been reevaluated by means of a polyphasic approach. Thus, 16S rRNA gene phylogeny and 16S–23S internal transcribed spacer (ITS) secondary structures coupled with morphological, ecological and physiological data are considered powerful tools for a better taxonomic and systematics resolution, leading to the description of novel genera and species. Additionally, underexplored and harsh environments, such as saline–alkaline lakes, have received special attention given they can be a source of novel cyanobacterial taxa. Here, a filamentous heterocytous strain, Nostocaceae CCM-UFV059, isolated from Laguna Amarga, Chile, was characterized applying the polyphasic approach; its fatty acid profile and physiological responses to salt (NaCl) were also determined. Morphologically, this strain was related to morphotypes of the Nostoc sensu lato group, being phylogenetically placed into the typical cluster of the genus Desmonostoc. CCM-UFV059 showed identity of the 16S rRNA gene as well as 16S–23S secondary structures that did not match those from known described species of the genus Desmonostoc, as well as distinct ecological and physiological traits. Taken together, these data allowed the description of the first strain of a member of the genus Desmonostoc from a saline–alkaline lake, named Desmonostoc salinum sp. nov., under the provisions of the International Code of Nomenclature for algae, fungi and plants. This finding extends the ecological coverage of the genus Desmonostoc, contributing to a better understanding of cyanobacterial diversity and systematics

Atributos ambientais na montagem da comunidade de cianobactérias da região do McMurdo Sound, Antártica

The variety of microbial ecosystems that exist in Antarctica represents an extraordinary opportunity for research on microbial ecology, diversity and evolution, particularly in terms of cyanobacteria. In this work we focus on the role of environment in controlling cyanobacterial mat assembly, and begin by describing the cyanobacterial diversity of mats along environmental gradients in the McMurdo Sound region, continental Antarctica. We then evaluated the role of environmental variables in determining their composition by analysing water and microbial cyanobacterial mat samples from 25 ponds from four distinct geographic sites: McMurdo Ice Shelf, Ross Island and Upper and Lower Wright Valleys. Finally we undertook a series of laboratory experiments to determine the extent to which species composition affects mat formation. Twenty nine morphospecies are identified and described in chapter one. Four were assigned to the order Chroococcales, three to the Nostocales and 22 to the Oscillatoriales. In chapter two, we investigated the factors that appeared to determine the presence or absence of morphospecies within the cyanobacterial mat community at each sampled pond. Ross Island, McMurdo Ice Shelf and Upper and Lower Wright Valleys ponds each showed some specific features in terms of physical-chemical factors and cyanobacteria diversity, though in many cases there was considerable overlap. Multivariate analysis based on physic-chemical variables showed that the ponds from each site tended to cluster by site, though with considerable overlap, and with the two Wright Valley and two coastal sites tending to be more similar to each other. This pattern tended to be reproduced in analysis of biomass and species composition data, and we were able to identify taxa that were broadly spread across the region and others that were more restricted by area. The importance of dispersal and growth conditions in driving this pattern is discussed. In chapter 3 we developed an experiment to evaluate the role of isolated cyanobacteria strains on the mat-building process. Six cyanobacteria strains, in varying combinations, were used to grow mats under laboratory conditions: CYN-50 (Phormidium cf. autumnale); CYN-68 (Leptolyngbya A); CYN-65 (Leptolyngbya B); CYN-66 (Microcoleus sp.); CYN-67 (cf. Aphanocapsa) and CYN-72 (Nostoc sp.). The content of chlorophyll-a, exopolysaccharide and organic matter was evaluated to assess mat development. At the end of our experiment, we observed that the mats developments showed variety in terms of their morphology, that oscillatorean cyanobacteria are required for coherent mat formation, but that different strains all produced effect mat matrices. P. autumnale produced the best developed mats. In conclusion, our findings provide an increased knowledge on the Antarctica cyanobacteria taxonomy and ecology in the McMurdo Sound region. We identified a mix of broadly tolerant, widely distributed organisms and other with more local distributions and specific environmental requirements. The significance of this in terms of management of Antarctic biodiversity is discussed.A variedade de ecossistemas microbianos que existe na Antártica representa uma oportunidade extraordinária para pesquisas sobre a ecologia, diversidade e evolução microbiana, principamente em termos de cianobactéria. Neste trabalho, foi avaliado o papel de atributos ambientais no controle da montagem de esteiras microbianas antárticas. Inicialmente foi caracterizado a diversidade cianobacteriana das esteiras ao longo de gradientes ambientais na região do McMurdo Sound, Antártica continental. Em seguida, foi avaliado o papel das variáveis ambientais na determinação da composição da assembléia de cianobactérias através da análise de amostras de água e esteiras de cianobactérias microbianas de 25 lagos distribuídos em quatro distintas áreas geográficas: McMurdo Ice Shelf, Ross Island e Upper e Lower Wright Valleys. Finalmente, foi realizado experimentos de laboratório para determinar a extensão com que a composição de espécies afeta a formação das esteiras microbianas. Vinte e nove morfoespécies foram identificadas e descritas no capítulo 1. Quatro foram designadas à ordem Chroococcales, três Nostocales e 22 Oscillatoriales. No segundo capítulo foram investigados os fatores que podem estar envolvidos na determinação da presença e/ou ausência de cianobactérias dentro da comunidade das esteiras microbianas em cada lago amostrado. Os lagos das regiões Ross Island, McMurdo Ice Shelf e Upper e Lower Wright Vallyes apresentaram algumas características específicas próprias de cada área em termos de fatores físico-químicos e diversidade de cianobactérias, embora em vários casos houve uma sobreposição considerável das características. A análise multivariada dos dados, com base em variáveis físico-químicas mostrou que os lagos de cada área amostrada tendeu a se agruparem por local, embora com considerável sobreposição, com os dois Wright Valleys e as duas zonas costeiras tendendo a ser mais semelhantes entre si. Este padrão tendeu a ser reproduzido em análises dos dados de biomassa e composição das espécies, onde foi possível indentificar táxons que foram amplamente espalhados por toda a região e outros que foram mais restritos por área. A importância da dispersão e condições de crescimento na condução desse padrão foi discutida. No terceiro capítulo foi desenvolvido um experimento para avaliar o papel de cepas de cianobactérias isoladas no processo de formação de esteiras microbianas. Seis cepas de cianobactérias foram utilizadas, em combinações variadas, para formar biofilmes em condições de laboratório: CYN-50 (Phormidium cf. autumnale); CYN-68 (Leptolyngbya A); CYN-65 (Leptolyngbya B); CYN-66 (Microcoleus sp.); CYN-67 (cf. Aphanocapsa) e CYN- 72 (Nostoc sp.). O conteúdo de clorofila-a, exopolissacarídeo e matéria orgânica foi avaliado e utilizado como medida de avaliação do desenvolvimento dos biofilmes. No final do experimento, observou-se que os biofilmes desenvolvidos mostraram-se diferentes em termos de sua morfologia e que as cianobactérias filamentosas “oscilatoriales” são requeridas para a formação de biofilme consistente, entretanto, todas as cepas morfologicamente diferentes produziram efeito nas matrizes dos biofilmes. Phormidium produziu o melhor biofilme desenvolvido. Em conclusão, este trabalho fornece um maior conhecimento sobre a taxonomia e ecologia de cianobactérias da Antártica na região do McMurdo Sound. Nós identificamos uma mistura de organismos amplamente distribuídos e tolerantes e outros com distribuições mais locais e requerimentos ambientais específicos. A significância destes em temos de gestão da biodiversidade antártica também foi discutida. *INGLÊS* SANTOS, Claudineia Lizieri dos, D.Sc., Universidade Federal de Viçosa, March of 2014. Environmental attributes in assembling cyanobacterial communities from the Mcmurdo Sound region, Antarctica.Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

Accumulation and toxicity of manganese in free floating aquatic macrophytes

A contaminação dos ecossistemas aquáticos pelo manganês (Mn) está associada, em grande escala, as ações antrópicas como, processos de manufatura de papel, resíduos de mineração e resíduos de esgoto domésticos. A fitorremediação consiste na utilização de plantas, dentre as quais as macrófitas aquáticas, com potencial para remover, degradar ou inativar contaminantes orgânicos e inorgânicos do meio, minimizando seus efeitos sobre os organismos vivos e o ambiente. O presente estudo avaliou o potencial fitorremediador de três espécies de macrófitas aquáticas: Azolla caroliniana, Salvinia minima e Spirodela polyrhiza para acumular Mn em solução. O acúmulo de Mn, o crescimento, o conteúdo de clorofila total e carotenóides foram avaliados nas três espécies submetidas a concentrações crescentes (0,05; 0,1; 0,2; 03; 0,4 mM) de Mn. As três espécies de macrófitas acumularam Mn em seus tecidos e a absorção foi dependente da concentração do metal em solução. As espécies se diferenciam quanto ao potencial para acumular Mn. Spirodela polyrhiza apresentou maiores concentrações de Mn acumulado (17,062 mg g-1 MS), seguida por S. minima (4,283 mg g-1 MS) e A. caroliniana (1,341 mg g-1 MS). O excesso de Mn causou a redução do conteúdo de clorofila total nas três espécies. O conteúdo de carotenóides diminui nas plantas de A. caroliniana e S. polyrhiza. Entretanto, apenas em S. polyrhiza o crescimento foi afetado significativamente. A partir destes resultados, a pesquisa buscou avaliar o efeito tóxico do Mn em S. polyrhiza, separadamente. O crescimento relativo, o conteúdo de pigmentos clorofila total, carotenóides e antocianinas, a atividade enzimática da catalase (CAT) e das peroxidases (POX) e alterações anatômicas foram avaliadas em plantas de S. polyrhiza expostas a concentração 0,4 mM de Mn. O excesso de Mn em solução reduziu o crescimento das plantas, assim como decresceu significativamente os conteúdos de clorofila total, carotenóides e antocianinas. A atividade da CAT também foi reduzida e a atividade da POX não apresentou diferença entre os tratamentos. A microscopia óptica mostrou um desarranjo nas lacunas do aerênquima em plantas expostas ao Mn. O conteúdo de Mn aumentou significativamente em plantas expostas ao metal (0,157 - 15,830 mg g-1MS). Os resultados mostraram que o excesso de Mn em solução acarretou efeitos tóxicos em plantas de S. polyrhiza. A alta concentração de Mn acumulada foi a causa dos efeitos tóxicos observados.The contamination of aquatic ecosystems by manganese (Mn) is greatly associated to human actions, such as the manufacturing processes of paper, waste from mining and domestic waste sewage. The phytoremediation consists of utilizing plants, such as aquatic macrophytes, with the potential to remove, degrade or inactivate organic and inorganic contaminants in the environment, minimizing its effects over it and liveng organisms. The present research evaluated the potential phytoremediator of three species of aquatic macrophytes: Azolla caroliniana, Salvinia minima and Spirodela polyrhiza to accumulate Mn in solution. The accumulation of Mn, growth, content of total chlorophyll and carotenoids were measured in three species submitted to increasing concentrations (0.05, 0.1, 0.2, 03 e 0.4 mM) of Mn. The three macrophytes species accumulated Mn in their tissue and the absorption was dependent on the concentration of metal presented in the solution. The species differed one another as for the potential to accumulate Mn. Spirodela. polyrhiza showed higher concentrations of Mn accumulated (17,062 mg g-1 MS), followed by S. minima (4,283 mg g-1 MS) and A. caroliniana (1,341 mg g-1 MS). The excess Mn caused a reduction of total chlorophyll content in the three species. The content of carotenoids decreased in the A. caroliniana and S. polyrhiza. However, growth only significantly affected the S. polyrhiza. Based on these results, the research aimed to evaluate the toxic effect of Mn in S. polyrhiza separately. The relative growth, the content of pigments total chlorophyll, carotenoids and anthocyanins, enzymatic activity of catalase (CAT) and peroxidases (POX) and anatomical modifications were evaluated in plants of S. polyrhiza which were exposed to the concentration of 0.4 mM of Mn. The excess of Mn in the solution reduced the growth of the plants, and significantly decreased the contents of total chlorophyll, carotenoids and anthocyanins. The activity of the CAT was also reduced and the activity of POX did not present differences among the treatments. Optical microscopy showed disarrangement in the gaps of the aerenchyma in plants exposed to Mn. The content of Mn significantly increased in the plants exposed to the metal (0.157 to 15.830 mg g-1ms). The results showed that the excess of Mn in solution caused toxic effects on plants of S. polyrhiza. The high concentration of Mn accumulated was cause of the toxic effects observed.Conselho Nacional de Desenvolvimento Científico e Tecnológic

Manganese accumulation and its effects on three tropical aquatic macrophytes: Azolla caroliniana, Salvinia mínima and Spirodela polyrhiza

Abstract The phytoremediation technique, which consists of using plants to remove ions, has been increasingly chosen over past decades due to its low-cost technology to mitigate contaminated areas. The aim of this study was to evaluate the potential of the aquatic macrophytes, Azolla caroliniana Willd, Salvinia minima Baker and Spirodela polyrhiza (L.) Schleiden, to accumulate manganese (Mn), an element which, at high concentrations, may be toxic to human populations. The three species accumulated Mn in their tissues and the absorption was independent of the metal concentration in the solution. Spirodela polyrhiza accumulated Mn at higher concentrations of the ion (17.062 mg g-1 MS), followed by S. minima (4.283 mg g-1 MS) and A. caroliniana (1.341 mg g-1 MS). Manganese excess reduced total chlorophyll content in all three species. Carotenoid content was reduced in A. caroliniana (27.02 %) and S. polyrhiza (25.34 %). Growth was only significantly reduced (21.34%) in S. polyrhiza. The species A. caroliniana and S. minima were able to tolerate excess Mn, but were inefficient regarding the accumulation of high concentrations of the metal. High accumulated Mn content in the tissues of S. polyrhiza suggests that the species is able to accumulate this element. Therefore, it has potential for use in phytoremediation and provides a new resource for exploring the Mn accumulation mechanism

Manganese accumulation and its effects on three tropical aquatic macrophytes: Azolla caroliniana, Salvinia mínima and Spirodela polyrhiza

Abstract The phytoremediation technique, which consists of using plants to remove ions, has been increasingly chosen over past decades due to its low-cost technology to mitigate contaminated areas. The aim of this study was to evaluate the potential of the aquatic macrophytes, Azolla caroliniana Willd, Salvinia minima Baker and Spirodela polyrhiza (L.) Schleiden, to accumulate manganese (Mn), an element which, at high concentrations, may be toxic to human populations. The three species accumulated Mn in their tissues and the absorption was independent of the metal concentration in the solution. Spirodela polyrhiza accumulated Mn at higher concentrations of the ion (17.062 mg g-1 MS), followed by S. minima (4.283 mg g-1 MS) and A. caroliniana (1.341 mg g-1 MS). Manganese excess reduced total chlorophyll content in all three species. Carotenoid content was reduced in A. caroliniana (27.02 %) and S. polyrhiza (25.34 %). Growth was only significantly reduced (21.34%) in S. polyrhiza. The species A. caroliniana and S. minima were able to tolerate excess Mn, but were inefficient regarding the accumulation of high concentrations of the metal. High accumulated Mn content in the tissues of S. polyrhiza suggests that the species is able to accumulate this element. Therefore, it has potential for use in phytoremediation and provides a new resource for exploring the Mn accumulation mechanism

Physiological and thylakoid ultrastructural changes in cyanobacteria in response to toxic manganese concentrations

In this study, two cyanobacterial strains (morphologically identified as Microcystis novacekii BA005 and Nostoc paludosum BA033) were exposed to different Mn concentrations: 7.0, 10.5, 15.7, 23.6 and 35.4 mg L−1 for BA005; and 15.0, 22.5, 33.7, 50.6, and 76.0 mg L−1 for BA033. Manganese toxicity was assessed by growth rate inhibition (EC50), chlorophyll a content, quantification of Mn accumulation in biomass and monitoring morphological and ultrastructural effects. The Mn EC50 values were 16 mg L−1 for BA005 and 39 mg L−1 for BA033, respectively. Reduction of chlorophyll a contents and ultrastructural changes were observed in cells exposed to Mn concentrations greater than 23.6 and 33.7 mg L−1 for BA005 and BA033. Damage to intrathylakoid spaces, increased amounts of polyphosphate granules and an increased number of carboxysomes were observed in both strains. In the context of the potential application of these strains in bioremediation approaches, BA005 was able to remove Mn almost completely from aqueous medium after 96 h exposure to an initial concentration of 10.5 mg L−1, and BA033 was capable of removing 38% when exposed to initial Mn concentration of 22.5 mg L−1. Our data shed light on how these cyanobacterial strains respond to Mn stress, as well as supporting their utility as organisms for monitoring Mn toxicity in industrial wastes and potential bioremediation application