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The evaluation of biotic integrity through multimetric analysis of the attributes of fish fauna is recognized as an important tool for water management and conservation policies. In this sense, the present study sought to elucidate tendencies in the use of the most used metrics in multimetric indices (MMIs), based on the fish assemblage, in Brazil. An electronic search of the literature was carried out in indexing databases of periodicals. The criteria used for the selection of scientific articles were to be carried out in Brazilian territory and the use of MMI with fish. Of total, 51.9% of the studies were applied in streams, with no temporal pattern. The highest concentration of studies was observed in the southeast region. In all, 99 different metrics were used, highlighting attributes related to trophic, tolerance and species composition. There was a increment of specific metrics over the years and environments, with the exception of rivers. In comparison to other environments, streams had significantly different metrics. Difficulties in the MMI proposal in Brazil are linked to the selection of aspects that characterize the condition of a habitat before the diagnosis of the ecological components in the classification of the environmental quality.

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Aim: The aim of this study was to assess the taxonomic aspects and geographical distribution of the periphytic desmids from two different substrates in the littoral zone of an urban artificial lake. Methods Samples of epiphytic and epilithic desmids were collected by grass and rock scraping, respectively, in two stations in the Cascavel municipal lake, Paraná, during April 2015, and March 2016 and 2017. In the laboratory, the taxa obtained from the samples were photographed and their morphometric characteristics recorded. The species composition of the desmid was characterized, and the frequency of occurrence as well as the geographic distribution of each taxon in the Paraná State were recorded. Results We identified 35 taxa, distributed in 10 genera. The most representative were Closterium Nitzsch ex Ralfs and Cosmarium Corda ex Ralfs. A high occurrence of sporadic taxa (60%) was observed and among the recorded taxa, the most frequent were Cosmarium pseudoconnatum Nordstedt var. pseudoconnatum and Desmidium grevillei (Kützing ex Ralfs) De Bary. Nine taxa were exclusive to the epilithic substrate and only Netrium digitus (Ralfs) Itzigsohn & Rothe var. digitus was exclusive to the epiphytic substrate, while the remaining 25 taxa occurred in both substrates. Seven taxa are new records for the Paraná State. Conclusion Although our results are of qualitative nature, they provide baseline data on the biogeographic distribution of taxa, which are crucial for future taxonomic and ecological studies that might contribute to the preservation of the biodiversity.

Impoundments caused by dams are often responsible for intense changes in physical, chemical, geomorphological and hydrological characteristics of rivers, and are one of the main causes in global freshwater biodiversity declines. When these changes derive from multiple cascading dams, the cumulative effect can amplify, causing more pronounced consequences than each individual reservoir, which may affect, among other factors, the biotic and functional conditions of fish fauna. We aim to evaluate the impact of dam cascades on fish functional diversity by applying trait‐based analysis. We evaluate the functional attributes (functional indices and community‐weighted means of trait values) and environmental variables at 11 sites, which encompassed different segments affected by the hydroelectric plants (transition, reservoir, reduced discharge section and tributary) in the Antas River Basin dam cascade system located in southern Brazil. The spatial differences of the functional indices (richness, evenness, divergence, dispersion and diversity) as well as the weighted averages of each functional trait were tested through analysis of variance. The most affected functional characteristics were those related to habitat exploration by detritivorous species, especially the use of food resources and body shape, as well as the type of swimming movement. These traits were more representative at the most downstream site of the complex. Thus, our results suggest that the cascade of dams acts in the functional homogenisation of the ichthyofauna in the intermediate stretches, mainly reflecting physical changes in habitat.

The Characidium orientale Buckup & Reis, 1997 larvae development is described using specimens collected in the natural environment of Antas River, in the Taquari-Antas river basin, Rio Grande do Sul, Brazil. Were considerate ontogenetic changes in morphology, pigmentation, fin morphology, and meristic characters. Thirty-six larvae (33 in the preflexion stage, two in flexion, and one in the postflexion stage), with a standard length between 4.24 and 11.26 mm were analyzed. The larvae of C. orientale are altricial and present fusiform body, subterminal mouth, long intestine with anal opening posterior to the vertical line over the median region of the body. Two chromatophores are evident in the interorbital region, as well pigments concentrated on the side of the body, forming a longitudinal stripe, and between the rays of the caudal fin, which intensify during the development. Also, a conspicuous remnant of the embryonic membrane (finfold) in front of the dorsal fin appears to be characteristic of species of the genus during larval development. The total number of myomeres varies from 32 to 35 (18-23 pre; 11-16 postanal). The main changes in morphometry occur during the preflexion stage and suggest physiological and behavioral changes.

O uso de peixes como bioindicadores possui grande importância no diagnóstico da integridade biótica de ecossistemas naturais. Os objetivos desse trabalho foram contribuir com o conhecimento da fauna de peixes de um fragmento de Mata Atlântica e avaliar a influência da operação de atividade antrópica sobre os padrões de composição e distribuição da ictiofauna. O estudo foi conduzido na área de influência de uma siderúrgica, em Santa Catarina. As amostragens ocorreram bimestralmente em quatro pontos, entre setembro de 2017 e outubro de 2018. A análise de dados incluiu a caracterização da ictiofauna quanto a constância, origem e ameaça, além de análises de suficiência amostral, variação espaço-temporal e avaliação da influência das variáveis ambientais. Foram registrados 924 indivíduos, pertencentes a 15 espécies, dentre as quais destaca-se Hollandichthys multifasciatus, considerado “Em Perigo” (EN) a nível estadual. Nós observamos um padrão de estruturação longitudinal vinculado a melhora na qualidade de água, com a redução dos níveis de condutividade e aumento do oxigênio no sentido montante-jusante. Demonstramos a importância de remanescentes ciliares de Mata Atlântica, que atuam na melhoria da qualidade de água e influenciam na estruturação da ictiofauna. Ademais, constatamos que as atividades do condomínio industrial avaliado não afetam diretamente a comunidade de peixes.

Intense hunting pressure and habitat loss have significantly reduced populations of the lowland tapir Tapirus terrestris in southern Brazil. Remaining individuals inhabit mainly legally protected areas. Here we report the first records outside of conservation areas in the state of Santa Catarina, over the last 30 years. These records were found during a mammal monitoring program, developed between May 2018 and July 2020. The records provide new evidence of the distribution of the species in Santa Catarina and reinforce the relevance of connectivity between protected areas of the Serra do Mar Ecological Corridor.