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The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications.

Social wasps build their nests using plant material and can thereby occupy different types of habitats. The organization of their colonies is generally based on complex communication systems that include chemical compounds of the cuticle that are shared with the material of their nests thus contributing to the specific chemical signature of their colony. These compounds can vary by environmental factors, in this case the nesting substrate may interfere with this composition. However, no study to date has investigated whether there is any relationship between the chemical signature of the colony and the nesting substrate of their nests. Therefore, in this study we investigated the relationship between the colonial chemical signature and the plant in which the colonies were nesting. Colonies of three species of social wasps and samples of plants where they nested were collected, then extractions of the chemical composition of adult wasps, nest material and plants were performed. The results show that the colonies of social wasps investigated here share their chemical composition with the plants where their nests were built. Our results suggest that the plant can provide the colony with more than just a place with ideal physical conditions and safety, but also compounds that compose the colonial chemical signature.

Este trabalho teve como objetivo avaliar a influência do uso e cobertura do solo e da qualidade da água em córregos da bacia do Alto rio Paraná sobre o potencial genotóxico em duas espécies de peixes nativas – Pimelodella avanhandavae e Hypostomus ancistroides. O uso e cobertura do solo nos córregos analisados está primariamente associado a atividades antropogênicas, sobretudo agrícolas. Os parâmetros físico-químicos da água se enquadraram aos limites estabelecidos pela resolução ambiental brasileira, com exceção da condutividade elétrica, que superou os valores máximos permitidos. Não encontramos diferenças significativas (p>0,05) entre os locais com relação à frequência de micronúcleos em ambas as espécies. Para outras anormalidades, no entanto, foram observadas diferenças significativas entre os locais comparados para P. avanhandavae, com maior frequência de invaginação do citoplasma no córrego Curral de Arame, que apresentou maior condutividade e menor concentração de oxigênio dissolvido que o córrego Laranja Doce. Para H. ancistroides, tanto núcleo lobulado quanto invaginação nuclear apresentaram maior frequência no córrego Curral de Arame, caracterizado por maior ocupação agrícola que o córrego Água Boa, que está localizado em uma área urbana. Nesse sentido, as frequências das anormalidades citadas indicam que, possivelmente, o impacto da agricultura esteja sendo mais prejudicial às espécies que os impactos decorrentes da ocupação urbana.

By understanding the intraspecific differences of traits presented by a species, we can gain greater insight into their variable functionality in microevolutionary processes relative to genetic and environmental factors leading to ecological adaptation and speciation. However, few studies have evaluated how intraspecific variation of cuticle hydrocarbons (CHCs) occurs in relation to the apolar part of ant venom. Therefore, this study aimed to evaluate the chemical composition of compounds present in the cuticle and venom of different populations of Ectatomma brunneum ants. To accomplish this, 310 foragers from different populations were collected. Analysis of CHCs and the apolar part of the venom was performed using a gas chromatograph coupled to a mass spectrometer. Our results show that both the composition of CHCs and the apolar part of the venom vary significantly among the different populations. Differences in composition between the two types of compounds correlate with the geographic distance between the populations. In this sense, the greater the distance, the smaller is the gene flow between them. On the other hand, particular environmental conditions, such as temperature, humidity and available resources, leading to changes generated by adaptation, could be responsible for a part of these differences.

The objective of this study was to evaluate the environmental integrity of three streams (along 13 sampling sites) of the Upper Parana River Basin using the benthic macroinvertebrate fauna as bioindicators and to answer the following question: Is there spatial variation, related to environmental quality, in the composition of these taxa in the streams? The invertebrates were sampled with a surber collector and for habitat analysis were determined characteristics as stream depth and width, water velocity, dissolved oxygen, pH, temperature, turbidity, and electrical conductivity. The environmental variables were analyzed by Principal Component Analysis in order to synthesize the data and identify the most important variables for ordering the collection sites. For biological analysis, the BMWP index was used. A Canonical Correlation Analysis of the environmental and biotic data was also performed in order to identify correlations between these two sets of variables. The collected macroinvertebrates belonged to four phyla (Nematoda, Annelida, Mollusca and Arthropoda), with Arthropoda being the most representative (54.93%), with the predominance of the order Diptera (30.29%). The most sensitive orders (Ephemeroptera, Plecoptera and Trichoptera) occurred in four sampling sites, corresponding to less impacted ones. Tolerant organisms, mainly chironomids, were found in all streams, including the most impacted places. These results indicate a spatial variation in the composition of the macroinvertebrates taxa in the streams, in response to variation of environmental quality.

O objetivo deste trabalho e avaliar se ha relacao entre a integridade ambiental de corregos urbanos da cidade de Dourados, estado do Mato Grosso do Sul, com a dieta e os aspectos reprodutivos de Serrapinnus notomelas (Characiformes: Characidae). Os exemplares foram coletados nas microbacias Laranja Doce e Agua Boa, ambiente menos impactado e mais impactado respectivamente, conforme evidenciado pela analise das variaveis ambientais avaliadas in loco . A analise da dieta da especie foi feita utilizando os metodos de Frequencia de Ocorrencia, Indice de Analise Volumetrica e Indice de Importância, alem de uma analise de variância multivariada permutacional (PERMANOVA) para testar se ha diferencas significativas na composicao da dieta entre os dois niveis de integridade ambiental. O Fator de Condicao foi calculado e comparado entre os locais por meio de uma Analise de Covariância (ANCOVA) com os dados de comprimento e peso logaritmizados. O Indice Gonadossomatico (IGS) foi calculado e comparado entre os locais pelo teste de Mann-Whitney e a fecundidade relativa foi testada por meio do teste t. A PERMANOVA indicou diferenca (p = 0,0001) entre os itens alimentares consumidos pela especie nos diferentes niveis de qualidade ambiental, destacando-se artropodes aquaticos (em especial larvas da familia Chironomidae) e sedimento no local mais impactado e algas da classe Chlorophyta no menos impactado. Estes resultados indicam que a origem dos itens alimentares consumidos esta relacionada ao nivel de integridade ambiental dos ambientes aquaticos. Nao observamos diferencas significativas entre os locais (p > 0,05) para o fator de condicao e para a fecundidade relativa. O IGS apresentou maiores valores no local mais impactado (p 0.05) for the condition factor and relative fecundity. The IGS presented higher values in the most impacted site (p < 0.0001). These results indicate that S. notomelas is a species with great diet plasticity and benefits of the anthropogenic alterations occurred in the studied environments.

Chemical compounds present on the cuticle of social insects are important in communication, as they are used in recognition of nestmates and sexual partners as well as in caste distinction, varying according to several factors, such as genetic and environmental. In this context, some studies have explored the cuticular chemical profile as a tool for assessing intra- and interspecific differences in social insects, although few studies have investigated this in social wasps. This study aimed to assess the differences in cuticular chemical profiles among different geographic samples of the wasp Mischocyttarus consimilis Zikán. Our hypothesis was that environmental factors are decisive to compose the cuticular chemical profiles of colonies of these social wasps and that there are differences regarding the geographic distribution among colonies. We used Fourier Transform Infrared-Photoacoustic Spectroscopy (FTIR-PAS) to assess the chemical profiles of samples. Our results show that despite there are differences between the cuticular chemical composition of the wasps' samples from different populations, there is no significant correlation compared to the spatial distribution of the colonies nor with the environment. Thus, our hypothesis was refuted, and we can infer that in this species neither exogenous nor genetic factors stand out to differentiate the chemical signature of their colonies, but a combination of both.

Social insects depend on their nests for protection against predation and abiotic threats. Accordingly, the chemical compounds present in the material wasps use to build their nests can both facilitate communication and repel predators. It is herein hypothesized that different wasp species build their nests with different structure and substrate materials and that such materials consist of chemical compounds related to unique wasp behavior and outside temperature variation. To test this hypothesis, nests were collected from three species of social wasps, the samples of which were subjected to temperature variation under laboratory conditions. The compounds present in the substrate were analyzed by gas chromatography coupled to mass spectrometry. Chemical compounds identified in the nest material of the three species responded differently to temperature variation. Chemical compounds from Polybia nests were altered significantly when subjected to temperature variation, whereas the nests of Polistes versicolor did not significantly change in relation to the control. The differences found between Polistes and Polybia nests may be related to genetic factors, but also to the type of nest they construct. It is possible that divergent evolutionary strategies for maintaining colony temperature, as a function of the chemical composition of the nests, may have appeared between wasps that have open and closed nests. In relatively small colonies, nest substrate is more resistant to temperature variation because it is composed of a greater diversity of elements and thus capable of holding heavier, longer carbon chains. Our results suggest that chemical compounds in the nest material of the three wasp species analysed responded differently to fluctuating ambient temperatures and that such variation could result from the biochemical differences of unique wasp species or from thermoregulation strategies of colonies.

The aim of this study was to analyze genotoxic effects in Astyanax lacustris and to test whether there are differences in the frequency of micronuclei in relation to sex, mass and length of individuals. The samples were carried out in the Tarumã Microbasin (Upper Paraná River, State of Mato Grosso do Sul, Brazil). In this study, we described this species presented the same relative frequency of micronuclei for both sexes, and for individuals of different masses and lengths. El objetivo de este estudio fue analizar los efectos genotóxicos en Astyanax lacustris y probar si existen diferencias en la frecuencia de micronúcleos en relación con el sexo, la masa y la longitud de los individuos. Las muestras se llevaron a cabo en la microcuenca Tarumã (río Alto Paraná, estado de Mato Grosso do Sul, Brasil). En este estudio, encontramos que la especie presentaba la misma frecuencia relativa de micronúcleos para ambos sexos y para individuos de diferentes masas y longitudes. O objetivo deste estudo foi analisar os efeitos genotóxicos em Astyanax lacustris e testar a existência de diferenças na frequência de micronúcleos em relação ao sexo, massa e comprimento dos indivíduos. As amostras foram coletadas na Microbacia de Tarumã (Alto Rio Paraná, Mato Grosso do Sul, Brasil). Neste estudo, relatamos que essa espécie apresentou a mesma frequência relativa de micronúcleos para ambos os sexos e para indivíduos de diferentes massas e comprimentos.

This study aimed to determine the concentration of metals in the water and in the liver tissue of fish (Anodus orinocensis, Hemiodus unimaculatus, Curimata vittata, and Plagioscion squamosissimus) in the lower Araguari River. Steps were also taken to estimate any difference in metal bioaccumulation in the liver of fish species at different trophic levels, determine any correlations between metals found in hepatic tissue of fish species relative to that found in river water, and evaluate the bioaccumulation factor. The metals analyzed in the water in the lower Araguari River (Cd, Pb, Fe, Hg, Cu, and Zn) exceeded the limits considered safe for aquatic life. We found a significant difference only in the bioaccumulation of Pb between A. orinocensis and C. vittata (F = 4.65, p = 0.005) and Cr between A. orinocensis and H. unimaculatus (F = 3.12, p = 0.03). Species of distinct trophic levels showed differences in metal concentration in liver. Cd and Cu showed bioaccumulation factor above 100, especially Cu with a relatively high value, for all fish species. The bioaccumulation of metals in the liver of fish species showed a positive correlation with the metals detected in the water of the Araguari River. In this sense, the lower course of the Araguari River is undergoing some type of environmental stress, making this study of additional valuable in diagnosing environmental quality pursuant to the development of environmental monitoring projects in order to guarantee the safety and maintenance of aquatic life.

The present study evaluated mutagenic and genotoxic effects and metal accumulation in the liver and musculature of Pterygoplichthys ambrosetti and Prochilodus lineatus in the Amambai River, a tributary of the Upper Paraná River in Brazil. We also evaluated the potential for these fish species as environmental bioindicators and performed risk assessment for conservation purposes. We found that P. ambrosetti had a higher frequency of micronuclei compared to P. lineatus (p 0.0001). There were no significant differences between species in other erythrocyte nuclear abnormalities (ENA) (p 0.05). For both species, the liver contained a higher concentration of metals (Cd, Pb, Cr, Cu, Fe, Zn, and Ni) than the musculature did (p 0.0001). Of the two species, P. ambrosetti was more suitable to evaluate mutagenic and genotoxic effects and metal accumulation in the liver and musculature, likely due to its resident behavior; hence, we highlight the potential of this species for use as an environmental bioindicator. The concentrations of non-essential metals observed in the fish confirm conditions of environmental stress in the Amambai River, possibly related to the discharge of pollutants and exacerbated by lack of native vegetation cover along the watercourse.

One of the most important contributions of forensic entomology is to assist criminal expertise to determine the postmortem interval, which depends on the duration of the immature stages of insects of forensic interest. On the other hand, the time of development of the different stages varies according to the species; therefore, its identification is essential. Currently, few studies have investigated the use of cuticular hydrocarbons, and none regarding fatty acids, as complementary taxonomic tools to expedite species identification. Therefore, we evaluated whether cuticular hydrocarbons together with fatty acids of eggs of flies of the family Calliphoridae, main group of forensic interest, can be used to distinguish species. The analyses were performed by chromatographic techniques. The results show that there are significant differences between the composition of cuticular hydrocarbons and fatty acids between species and, therefore, they can be used to provide a complementary taxonomic tool to expedite the forensic expertise.

Changes in diet of Laetacara araguaiae Ottoni and Costa, 2009 were evaluated in the Sucuriu River (Upper Parana basin, Brazil) in an area with a small hydroelectric power plant, both before and after the formation of the reservoir, in order to answer: Did the construction of the reservoir affected the diet of this species? The results showed greater change of diet composition in the upstream section of the reservoir. It was observed that before the formation of the reservoir and the first year after, the individuals from upstream section formed a group characterized by an insectivorous diet. With the dam construction and habitat change we observed that aquatic plant material, sediment, and algae predominated in the diet. These results show the opportunistic feeding habit of L. araguaiae and contribute to the understanding of how the impoundment of rivers can influence the trophic dynamics of the ichthyofauna.

The objective of this study was to evaluate the efficiency of Laser-Induced Breakdown Spectroscopy (LIBS) to detect the presence of bioaccumulated Fe and Pb in scales of Salminus brasiliensis and Prochilodus lineatus, and to compare the results from this technique with those obtained using the conventional atomic absorption spectrometry technique. The study used fish collected in the Amambai River, Upper Parana River, Brazil. The LIBS technique detected the presence of Fe in S. brasiliensis scales and Fe and Pb in P. lineatus scales on different regions. Using atomic absorption spectrometry, we verified a significant difference in Fe concentration in scales between the species analyzed, with a higher concentration in S. brasiliensis than in P. lineatus (p = 0.0004). Pb was not detected using atomic absorption spectrometry in either species because the concentration of this element was below the limit of detection of this technique. The LIBS technique was efficient in detecting Fe and Pb in scales of the two species analyzed, proving to be a promising tool for environmental monitoring.

This study assessed the quality of vegetation cover in the Parque Estadual das Varzeas do Rio Ivinhema (PEVRI, Upper Parana River basin, MS, Brazil), the concentration of metals (Cd, Pb, Cr, Cu, Fe, Zn and Ni) in water and muscle and hepatic tissues of five fish species collected in the PEVRI – Hemiodus orthonops, Leporinus friderici, Prochilodus lineatus, Pterodoras granulosus and Pimelodus maculatus – in addition to non-carcinogenic risk assessment and genotoxicity potential in these species. Regarding vegetation index, we found that only 26.25% of the PEVRI area is occupied by denser vegetation. In the sites analyzed, Cd, Cu, Fe and Ni showed high concentrations in water, above the reference values established by the legislation. In the muscle and hepatic tissues of the fish species analyzed, Cd and Pb values exceeded the reference limits. The genotoxic alterations identified in erythrocytes of the fish species studied were nuclear invagination, nuclear budding, picnosis, binucleated cell and lobulate nucleus. For the non-carcinogenic risk assessment in fish, Cd and Pb presented values greater than 1, indicating risk in the consumption of these fish. In the bioaccumulation factor, Cd and Pb were greater than 100 in all fish species analyzed, except for Pb in L. friderici. The results indicated that the water resources of the PEVRI are being affected by some type of contaminant, probably due to anthropic activities carried out around the park or carried from the upper portions of the basin through the drainage system.

O objetivo do estudo foi avaliar parâmetros físico-químicos quantitativos da água proveniente de córregos na microbacia Tarumã (MS, Brasil), quantificar metais (Cd, Pb, Cr, Cu, Fe, Zn e Ni) nos sedimentos de fundo desses córregos e avaliar quali-quantitativamente o índice de vegetação de diferença normalizado dos locais (NDVI) por meio de imagens de satélite. Os valores de turbidez e condutividade elétrica da água estavam mais altos nos pontos mais próximos da região urbana. Na análise do NDVI, os pontos P1, P2 e P4 apresentaram a vegetação ciliar local reduzida, classificada em baixo ou muito baixo. Nos locais P3, P5 e P6 constatamos maiores proporções de vegetação em níveis moderado e baixo. Em relação aos metais nos sedimentos, todos os pontos amostrados apresentaram concentrações de metais abaixo dos limites estabelecidos pela legislação vigente. O baixo índice de cobertura vegetal em torno dos córregos na Microbacia Tarumã, principalmente nos locais de nascentes, pode comprometer o equilíbrio desse sistema.

The streams and rivers of the Upper Paraná River Basin have been seriously affected by impacts of high population density around the basin area. Fishes are widely used as models to assess the health of aquatic ecosystems, being considered as bioindicators of environmental pollution. In this context, our objective was to assess the potential genotoxic and mutagenic effects of the polluted water in three native fish species (Astyanax lacustris, Hypostomus ancistroides, and Rhamdia quelen) from Tarumã Microbasin, Upper Paraná River, Brazil. We also investigated the concentration of metals in water and in fish muscle to verify bioavailability and bioaccumulation of metals. For both less impacted sites (LI) and impacted sites (IMP) of the microbasin, the concentrations of metals were above the maximum limit allowed by Brazilian legislation (Resolution CONAMA 357/2005), except for Pb, total Cr, and Cu at LI sites and total Cr at IMP sites. A. lacustris showed a higher frequency of micronuclei (MN) at IMP sites compared with LI sites (p 0.0001). We found no significant differences in MN frequency between site classes for H. ancistroides and R. quelen (p 0.05). There were no significant differences between site classes regarding to nuclear abnormalities in erythrocytes frequencies (p 0.05). A. lacustris from IMP sites had higher concentrations of Pb, Cu, Fe, Zn, and Ni in muscle tissue (p 0.05), whereas H. ancistroides from IMP sites had higher concentration of Cr, Cu, and Ni (p 0.0001) and R. quelen showed higher concentration of Cd, Fe, and Ni at these sites (p 0.0001). So, the chosen biomarkers are able to identify the environmental risk of the water pollution.

The objective of this research was to evaluate land use and occupation in the landscape surrounding two neotropical streams of the Upper Parana River in Brazil and to investigate if the water from these streams induces erythrocyte nuclear abnormalities in Astyanax lacustris. We observed that the areas surrounding the streams are predominantly used for agricultural purposes (73.46% of the total area), followed by buildings (15.21%). Only 8.78% of the area consisted of forest fragments. We observed higher frequencies of micronuclei in erythrocytes of A. lacustris exposed to water from impacted sites (IMP) compared with less impacted sites and the negative control (NC) (p

This study analyzed physicochemical characteristics of the water, degradation of the surroundings and the influence of these factors on the diet of two fish species of Astyanax in Taruma stream microbasin, central western Brazil. Fish were collected in eight sites between 2007 and 2010, using gillnets and sieves. Environmental variables were evaluated by a principal component analysis and the diet based on Spearman’s correlation. The variables width, type of riparian vegetation, pH, conductivity, total dissolved solids, temperature, oxidation and reduction potential, presence of waste, and altitude have separated the sampling sites into two groups: ‘less impacted’ and ‘more impacted’. The two characid species presented omnivorous habit, typical of disturbed environments. The consumption of food resources was different over the space: terrestrial plants and sediment were more important in the most impacted sites for both species. And specifically to Astyanax altiparanae the order of importance of the food was distinct between most and less impacted sites. These data indicated that the diet of these species is a suitable tool for analyzing the environmental quality of the studied sites.

Com o objetivo de descrever alguns aspectos populacionais e reprodutivos de Bryconamericus stramineus em riachos da bacia do rio Guirai, Alto Rio Parana, realizamos amostragens bimestrais de Outubro/2006 a Agosto/2007 em sete riachos da bacia. Foram coletados 960 individuos, sendo 532 femeas, 316 machos e 112 de sexo indeterminado. Constatamos variacao significativa na proporcao sexual (Χ2 = 32,82; p < 0,001). As femeas foram maiores (59,7 mm) que os machos (58,9 mm); no entanto, os machos apresentaram maior coeficiente angular de crescimento (b). Estimamos que 50% das femeas estao sexualmente maduras com 36,4 mm de comprimento padrao. As maiores frequencias de femeas com ovarios desenvolvidos foram observadas em Outubro, sendo que o unico mes em que nao foram encontradas femeas maduras foi Junho. A fecundidade media foi estimada em 313 ovocitos e a fecundidade relativa foi de 184,6 ovocitos/g. O comprimento assintotico foi estimado em 62,8 mm e a taxa de crescimento em 0,76. O indice de performance de crescimento foi calculado em 3,47, a longevidade em 3,94 anos e a mortalidade em 1,18. O padrao de recrutamento da especie estudada apresentou picos concentrados no periodo de menor pluviosidade.

AIM: The present study analyzed the spatial variation in fish species richness and composition in streams of the Ivinhema River basin, Upper Paraná basin, determining the relationship between local and regional descriptors of the fish assemblage organization; METHOD: From 2001 to 2011 we sampled 200 stream stretches, using different sampling methods. Local species richness and composition were analyzed using univariate and multivariate methods to detect patterns of variation in the fish assemblage organization; RESULTS: We identified 111 fish species in the streams, and estimated the occurrence of 117 fish species (CIα0.05 = 111 to 123) with lower species richness in headwater streams compared to the lower parts of the basin. The fish species recorded were predominantly of small size, and the mean size increased from the headwaters to the river mouth. The four most common species are widely distributed in the basin. However, 24 species are allocthonous to the Upper Paraná basin, and two species (Chaetobranchopsis australis and Apistogramma commbrae) are recorded here for the first time in the Upper Paraná basin. Altitude was the main determinant of local fish species richness and composition, and a discontinuity in assemblage organization (richness, composition, fish size) was detected at approximately 430 m a.s.l.; CONCLUSION: Streams of the Ivinhema River basin are inhabited mainly by small-sized fishes; and longitudinal variation, interacting with local characteristics, determines the fish assemblage patterns. OBJETIVOS: O presente estudo tem como objetivo analisar a variação especial na riqueza e composição de espécies de peixes em riachos da bacia do rio Ivinhema, Alto Rio Paraná determinando a relação entre características locais e regionais na organização das assembleias de peixes; MÉTODOS: Amostramos 200 trechos de riachos entre 2001 e 2011 utilizando diferentes petrecho de pesca. A riqueza local e composição de espécies foram analisadas utilizando métodos uni e multivariados buscando detectar padrões na organização das assembleias de peixes; RESULTADOS: Identificamos 111 espécies de peixes nos riachos amostrados e estimamos a ocorrência de 117 espécies de peixes (ICα0,05 = 111 a 123) com menor riqueza de espécies nos trechos de cabeceira quando comparados aos trechos inferiores da bacia. As espécies de peixes registradas são predominantemente de pequeno porte, com incremento no tamanho médio das nascentes para a foz do rio. As quatro espécies mais comuns são de ampla distribuição na bacia, no entanto, 24 espécies são alóctones ao Alto Rio Paraná e duas espécies (Chaetobranchopsis australis e Apistogramma commbrae) são registradas pela primeira vez na bacia do Alto Rio Paraná. A altitude foi o principal determinante da riqueza e composição de espécies e uma descontinuidade na organização das assembleias (riqueza, composição e tamanho dos peixes) foi detectada a aproximadamente 430 m de altitude; CONCLUSÕES: Os riachos da bacia do rio Ivinhema apresentam principalmente espécies de pequeno porte e a variação de altitude, interagindo com fatores locais, determinam os padrões observados nas assembleias de peixes.

This study aimed to describe the diversity of fish parasites in the Amambai River, in the Mato Grosso do Sul State, and generate information to facilitate studies of the biotic integrity of the region. During the period of September 2015 and July 2015, 48 specimens of 11 species of fish were analyzed for parasites. A total of 56.25% of the fish sampled from the Amambai River were infected with one or more metazoan species. A total of 21,514 parasite specimens belonging to 24 different species we found; they were distributed among six groups: Acanthocephala (Neoechinorhynchida), Cestoda (Proteocephalidea), Crustacea (Ergasilidae), Digenea (Cladorchiidae, Dadaytrema ), Monogenea (Dactylogyridae) and Nematoda (Atractidae, Cucullanidae, Camallanidae, Rhabdochonidae). Of these, a monogenean, Mymarothecium sp. and four nematodes – Cucullanus sp.; Procamallanus ( Spirocamallanus ) inopinatus Travassos, Artigas, and Pereira, 1928; Rabdochona acuminate (Molin, 1860); and Rondonia rondoni Travassos, 1920 – were recorded for the first time on new hosts. This is the first work to gather information about the parasite fauna of fish from Amambai River in the Mato Grosso do Sul State, and provides records that contribute new reports of the occurrence of parasites in new locations.

Univ Estadual Mato Grosso Sul, Lab Anal & Monitoramento Ambiental Gas Nat, GASLAB, BR-79804970 Dourados, MS, Brazil

O objetivo deste trabalho é descrever a variação sazonal do fator de condição e do ciclo de desenvolvimento gonadal de Pimelodella cf. gracilis no rio Amambai, Estado de Mato Grosso do Sul. O comprimento e o peso de 232 indivíduos foram obtidos para cálculo do Fator de Condição Alométrico. Para as fêmeas (n=162), obtivemos, ainda, o peso e o estádio de maturação dos ovários, para cálculo do IGS e da freqüência percentual desses estádios em cada estação do ano. Os resultados obtidos indicam que os maiores valores de IGS correspondem às estações primavera e verão. Com base nisso, conclui-se que o período de desova da espécie está compreendido entre os meses de outubro e abril, embora não tenha sido possível determinar com maior precisão quando esse evento ocorre. Os maiores valores do fator de condição foram observados no verão, como possível conseqüência da maior atividade alimentar que os indivíduos apresentaram durante a primavera.The aim of this study is to describe the seasonal variations of condition factor and of the gonadal development cycle of Pimelodella cf. gracilis in Amambai River (MS, Brazil). The length and weight of 232 individuals were measured to calculate the Allometric Condition Factor. For the females (n=162), we also obtained the ovarian weight and the gonadal maturity stages in order to calculate the GSI and the relative frequency (%) of this stages at each season of the year. Results indicate that the highest GSI values were registered in spring and summer. Thus, we concluded that the spawning season of this species occurs between October and April. However, it was not possible to identify more precisely when this event occurs. The highest values of condition factor were observed in summer, as a probable consequence of the more intensive feeding activity that individuals demonstrate during the spring.

Esse estudo teve como objetivo descrever a dieta e analisar a atividade alimentar de Pimelodella cf. gracilis no rio Amambai, Estado de Mato Grosso do Sul, ao longo das quatro estações do ano. Para tanto, analisou-se o conteúdo estomacal e calculou-se o Índice de Repleção Estomacal de 232 indivíduos. Os resultados obtidos demonstram que essa espécie é onívora e generalista, pois consome itens alimentares de origens diversas, tais como material vegetal, insetos terrestres e aquáticos, moluscos, escamas de peixes, sedimentos e material não-identificado. Apesar disso, o item material vegetal foi predominante na dieta ao longo de todo o ano, demonstrando que, embora onívora, essa espécie apresenta tendência à herbivoria. A dieta básica mostrou variações sazonais em sua composição, pois observou-se que alimentos alóctones têm sua importância aumentada nas estações mais quentes e chuvosas. Além disso, também foram registradas alterações sazonais na atividade alimentar, possivelmente influenciadas por fatores climáticos (temperatura e pluviosidade) e fisiológicos (ciclo reprodutivo).The aim of this study is to describe the diet and the feeding activity of Pimelodella cf. gracilis in Amambai river, Mato Grosso do Sul State, Brazil, along the four seasons of the year. For this, the stomach contents of 232 individuals were analyzed and their Stomach Fullness Index was calculated. The results indicate that this species is omnivorous and generalist, so it consumes feeding items of several origins, such as plant material, terrestrial and aquatic insects, mollusks, fish scales, sediments and non-identified material. Notwithstanding this, the plant material was predominant in the diet along the whole year, indicating that Pimelodella cf. gracilis tends to herbivorous habit. The composition of the basic diet changed seasonally, so we observed that allochthonous items have their importance increased in the warm and rainy seasons. Besides this, we also observed seasonal shifts in the feeding activity, probably due to climactic (temperature and precipitation) and physiological factors (reproductive cycle).

This study analyses the ontogenetic diet shifts of a Neotropical catfish, Pimelodus maculatus (Siluriformes, Pimelodidae), from an ecomorphological standpoint. We collected 241 individuals in the Piracicaba River (Brazil) and, in the laboratory, seven morphometric variables were recorded from each specimen: standard length (SL), body depth, head length, snout length, eye diameter, mouth height and mouth width. After standardizing these measurements (as a proportion of SL), linear regressions were run to determine whether their growth was isometric or allometric in relation to SL. The diet analysis shows that the main food item for fish in the smaller size classes is aquatic insects, while the largest individuals feed mainly on other fish. As the great majority of the morphometric variables analyzed showed isometric growth as a function of SL – which means that these fish do not change their shape significantly during their lives – the ontogenetic diet shifts may be seen as a consequence of the absolute size increment of their mouth gape, which allows individuals to maximize their energetic gain by ingesting larger prey with a higher caloric content.

Dentre os trabalhos que objetivam o estudo da condição de peixes com o uso do método alométrico (K=W/Lb), não há um consenso sobre o procedimento mais adequado para o cálculo do coeficiente b, pois alguns autores utilizam um coeficiente constante para todas as sub-amostras (estações do ano, por exemplo), enquanto outros calculam um valor de b para cada sub-amostra. Com a intenção de demonstrar qual desses procedimentos é mais adequado, este trabalho verificou-se que a utilização de um valor de b para cada sub-amostra provoca distorções nos valores do Fator de Condição. Conclui-se, então, que o método que calcula o coeficiente b a partir do agrupamento de todos os indivíduos e o utiliza com um valor constante para todas as sub-amostras é, dentre os dois procedimentos testados, o mais adequado para estudo da condição de peixes.There is no agreement among authors that study fish condition by the allometric method (K=W/Lb) with regard to the best procedure for b coefficient calculation. Some authors use a constant coefficient for all sub-samples (seasons of the year, for instance), whilst others calculate b value for each sub-sample. To demonstrate which of these methods fits better, this study verified that the use of one b value for each sub-sample leads to distortion of Condition Factor values. Comparing the two tested methods, it may be concluded that the method which calculates b coefficient from groupings of all individuals and uses b as a constant value for all sub-samples is the most convenient method to study fish condition.

Em estudos sobre alimentação de peixes, é prática comum determinar a dieta de uma espécie com base na análise do conteúdo estomacal. Para a realização destes estudos normalmente são aplicados os métodos de ocorrência, numérico, volumétrico e gravimétrico. A utilização destes métodos, entretanto, nem sempre é possível, e o objetivo deste trabalho é propor uma metodologia alternativa baseada na atribuição de pontos aos itens alimentares a partir da obtenção da massa total e de uma simples inspeção visual dos conteúdos estomacaisA very common practice in studies on fish feeding is to determine the diet of the species by an analysis of stomach contents. It is undertaken by the methods of numerical, volumetric, gravimetric and occurrence frequencies. Since their utilization is not always possible, an alternative method based on attribution of points is suggested. It consists of evaluating food items starting from total food weight and simple visual inspection of stomach contents

This study aimed at analyzing the influence of different levels of environmental integrity of streams of the Ivinhema river basin (Mato Grosso do Sul State, Brazil) on the diet of A. altiparanae . Samplings were performed from July 2001 to November 2011 at 101 sites, using sieves, seining and gill nets, and electrofishing. Streams were classified into three levels of environmental integrity. We analyzed 664 stomachs with the methods of frequency of occurrence and volumetric analysis index, combined in the Importance Index (AI). The species was omnivorous, with predominance of allochthonous resources. At the least impacted sites, the most representative resource was allochthonous plant material; and in the altered sites in the rainy period the most consumed item was allochthonous arthropods. On the other hand, at the most impacted sites in the dry period there was a lower consumption of allochthonous plant material and allochthonous arthropods, compared with other levels of environmental integrity considered, with higher consumption of autochthonous arthropods. The results evidenced that in the least impacted sites there was greater contribution from allochthonous resources, probably because these environments show a more preserved riparian forest.

This study analyzed physicochemical characteristics of the water, degradation of the surroundings and the influence of these factors on the diet of two fish species of Astyanax in Tarumã stream microbasin, central western Brazil. Fish were collected in eight sites between 2007 and 2010, using gillnets and sieves. Environmental variables were evaluated by a principal component analysis and the diet based on Spearman’s correlation. The variables width, type of riparian vegetation, pH, conductivity, total dissolved solids, temperature, oxidation and reduction potential, presence of waste, and altitude have separated the sampling sites into two groups: ‘less impacted’ and ‘more impacted’. The two characid species presented omnivorous habit, typical of disturbed environments. The consumption of food resources was different over the space: terrestrial plants and sediment were more important in the most impacted sites for both species. And specifically to Astyanax altiparanae the order of importance of the food was distinct between most and less impacted sites. These data indicated that the diet of these species is a suitable tool for analyzing the environmental quality of the studied sites.

O objetivo deste estudo foi caracterizar a dieta das espécies de peixes mais abundantes no córrego Franco (Ivinhema, MS). Os peixes foram capturados mensalmente, no período de março de 2006 a fevereiro de 2007. Para inferência da dieta de espécies que se alimentam de itens macroscópicos, o conteúdo estomacal de cada indivíduo foi retirado, pesado (em g) e posteriormente analisando sob lupa. Os dados obtidos para cada espécie em cada unidade amostral foram analisados a partir dos seguintes métodos: Freqüência de Ocorrência, Índice de Análise Volumétrica e Índice de Importância. Foram coletadas 17 espécies de peixes, na sua grande maioria Characiformes, com dez espécies, duas espécies de Siluriformes, duas de Perciformes, duas de Gymnotiformes e uma de Synbranchiformes. A alimentação das duas espécies estudadas do gênero Astyanax baseou-se principalmente de itens de origem vegetal independentemente da origem; Serrapinnus notomelas alimentou-se de itens vegetais, predominantemente de algas; Hemigrammus marginatus apresentou um hábito alimentar insetívoro principalmente de origem alóctone; Corydoras aeneus e Eigenmannia trilineata alimentaram-se basicamente de insetos aquáticos; sedimento foi o principal item alimentar de Hypostomus ancistroides, seguido por algas e macrófitas; Crenicichla britiskii alimentou-se principalmente de insetos terrestres. Diet of fish fauna from Franco stream, Mato Grosso do Sul, Brazil. The aim of this study was to characterize the diet of the most abundant fish species in the Franco stream (Ivinhema, MS). Fish were captured monthly, from March 2006 to February 2007. To infer the diet of species that feed on macroscopic items, the stomach contents of each individual was removed, weighed (g) and subsequently analyzed under stereomicroscope. The data obtained for each species in each sampling unit were analyzed with the following methods: Frequency of Occurrence, Volumetric Analysis Index and Index of Importance. We collected 17 species of fish, the vast majority Characiformes, with ten species, two species of Siluriformes, two of Perciformes, two of Gymnotiformes and one of Synbranchiformes. The diet of two species of the genus Astyanax was based mainly on items of plant origin; Serrapinnus notomelas fed up of plant items, mainly from algae; Hemigrammus marginatus showed a mainly insectivorous feeding habits of alien origin, Corydoras aeneus and Eigenmannia trilineata fed up primarily of aquatic insects; sediment was the main food item of Hypostomus ancistroides, followed by algae and macrophytes; Crenicichla britiskii fed mainly on terrestrial insects.

Diversidade de formigas epigéicas (Hymenoptera, Formicidae) em ambientes no Centro-Oeste do Brasil. Foi comparada, através do uso de índices de diversidade e modelos de abundância de espécies, a diversidade das comunidades de formigas epigéicas que ocorrem em duas estruturas vegetacionais diferentes: mata nativa e cultura de eucalipto. Para a captura das formigas foram utilizadas 800 armadilhas de solo do tipo pitfall, em oito amostras distintas. Um total de 85 espécies, distribuídas em 36 gêneros de sete subfamílias foram coletadas nos dois ambientes, sendo que destas, 83 ocorreram na mata nativa e 60 na cultura de eucalipto. A diversidade de espécies de formigas calculada pelo índice de Simpson não foi significativamente diferente entre os ambientes, ao contrário do resultado obtido a partir da aplicação do índice de Shannon, o qual indicou maior diversidade de espécies na mata nativa. O modelo log-series não se ajustou satisfatoriamente aos dados das comunidades de formigas encontradas na cultura de eucalipto e na mata nativa, mas o modelo log-normal mostrou-se adequado para descrever a estrutura das comunidades dos dois ambientes. O modelo broken-stick, que representa uma comunidade bem estruturada, ajustou-se apenas aos dados da mata nativa. We compared, through the use of diversity indices and species abundance models, the diversity of communities of epigeous ants occurring in two different vegetational structures: native forest and eucalyptus plantation. To capture the ants, 800 soil pitfall traps were used, in eight sample series. A total of 85 species, belonging to 36 genera of seven subfamilies were collected in the two environments. Of these species, 83 occurred in the native forest and 60 in the eucalyptus plantation. The species diversity as evaluated by Simpson's index was not significantly different between the environments, but the Shannon index indicated a higher diversity of species in the native forest. The log-series model could not be adjusted satisfactorily to the data for the ant communities from either the eucalyptus plantation or the native forest; however, the log-normal model appeared appropriate to describe the community structure in both environments. The broken-stick model, which represents a well-structured community, was only adjusted to the data for the native forest sites.