Distribution of diversity of fishes in an Andean fluvial network

Introduction: The distribution of freshwater fishes in the Colombian Andes results from the interaction between historical and recent factors. Currently, the Andean landscape is facing rapid transformation processes. However, the knowledge regarding species distribution and environmental requirements is advancing slower than the transformations underway in the fluvial networks. Objective: To understand the conformation of the fish assemblage in the middle and lower Cauca River basin, considering the local environmental context before the construction of the Ituango Dam, and quantifying β diversity and its two components (turnover and nestedness) amongst local fish communities. Methods: 58 localities were monitored during nine years (between February 2010 and November 2018), the period before the dam's operation. The species richness (α-diversity), species turnover (β-diversity), and assemblage composition were estimated for the given localities. Results: 114 species were recorded, representing ~ 49 % of the total richness of known species for the Magdalena basin. The richness distribution showed that the number of species varies among the aquatic environments. Swamps presented the most significant number of species, followed by the Cauca River, while streams had the lowest values of richness. The spatial analyses of β-diversity revealed a high variation component in the study area due to species replacement between the aquatic environments. Conclusions: The implementation of long-term monitoring allowed us to recognize that the Cauca River basin conserves a great variety of species-rich environments. The species turnover indicates a high proportion of endemism or multiple sites with unique species. Finally, our study will serve as a baseline to verify, over time, whether the dam's construction is associated with essential changes in the structure of fish communities.

Introducción: La distribución de los peces de agua dulce en los Andes colombianos es el resultado de la interacción entre factores históricos y recientes. Actualmente, el paisaje Andino enfrenta procesos de rápida transformación. Sin embargo, el conocimiento sobre la distribución de las especies y sus requerimientos ambientales no avanza tan rápido como las transformaciones en curso en las redes fluviales. Objetivo: Comprender la conformación del ensamble de peces en la cuenca media y baja del río Cauca, considerando el contexto ambiental local antes de la construcción de la represa de Ituango, y cuantificar la diversidad beta y sus dos componentes (recambio y anidamiento) entre las comunidades de peces locales. Métodos: Se analizaron 58 localidades durante nueve años (entre febrero 2010 y noviembre 2018), período previo a la operación de la represa. La riqueza de especies (diversidad α), el recambio de especies (diversidad β) y la composición del conjunto se estimaron para las localidades dadas. Resultados: Se registraron 114 especies, que representan ~ 49 % de la riqueza total de especies conocidas para la cuenca del Magdalena. La distribución de la riqueza mostró que el número de especies varía entre los ambientes acuáticos. Las ciénagas presentaron el mayor número de especies, seguidas por el río Cauca, mientras que las quebradas presentaron los valores más bajos de riqueza. Los análisis espaciales de la diversidad β revelaron un alto componente de variación en el área de estudio debido al reemplazo de especies entre los ambientes acuáticos. Conclusiones: La implementación del monitoreo a largo plazo permitió reconocer que la cuenca del río Cauca conserva una gran variedad de ambientes ricos en especies. El recambio de especies indica una alta proporción de endemismo o múltiples sitios con especies únicas. Finalmente, nuestro estudio servirá como línea base para verificar, con el tiempo, si la construcción de la represa está asociada con cambios esenciales en la estructura de las comunidades de peces.

Influence of urbanization on stream fish assemblages in three microbasins in the Upper Paraná River Basin / Influência da urbanização em assembleias de peixes de riachos em três microbacias na bacia do Alto Rio Paraná

Abstract The colonization pattern of fish assemblages in streams is often studied in the context of environmental filters. On the other hand, when fish assemblages are subjected to anthropogenic effects, variables associated with environmental quality assume more importance. Therefore, this work evaluated the richness and composition of fish from streams sampled at different urbanization levels, aiming to determine any direct effects on the structure of fish assemblages. To accomplish this, samples were collected from 2003 to 2011 at 31 sites distributed among 3 microbasins in the Rio Ivinhema Basin, Alto Rio Paraná. Based on environmental variables, physicochemical of the water and analysis of the use and occupation of the soil, the microbasins were classified into different urbanization levels (low, medium and high). A total of 4,320 individuals were sampled, out of which 57 fish species were recorded. Sampled sites with medium urbanization level presented higher richness compared to sampled sites with high urbanization level which presented lower richness. Species richness in these sites was explained mainly by water temperature and water velocity. Results confirmed that urbanization does directly affect environmental integrity, which, in turn, can lead to the homogenization of stream assemblages.

Resumo Estudos sobre assembleias de peixes em riachos enfatizam o papel dos filtros ambientais associados ao padrão de colonização das assembleias, por outro lado, quando a assembleia está sujeita aos efeitos antropogênicos, as variáveis ambientais associadas à qualidade ambiental assumem maior importância. Dessa forma, o objetivo deste estudo foi analisar a riqueza e a composição de peixes de riachos amostrados em diferentes níveis de urbanização, buscando evidenciar se o efeito reflete diretamente na estrutura das assembleias. As amostragens foram realizadas em 31 locais distribuídos em três microbacias na bacia Rio Ivinhema, Alto Rio Paraná, no período de 2003 a 2011. Com base nas variáveis ambientais, físico-químicos da água e análise do uso e ocupação do solo as microbacias foram classificadas em diferentes níveis de urbanização (baixo, médio e alto). Foram amostrados um total 4.320 indivíduos, dos quais foram registradas 57 espécies de peixes. Os locais amostrados com influência média da urbanização apresentaram maior riqueza de espécies, entretanto, os locais amostrados com alta influência da urbanização apresentaram menor riqueza de espécies. Dessa forma, constatamos que a urbanização influencia diretamente na integridade ambiental, que pode levar a homogeneização das assembleias de riachos.

Influence of urbanization on stream fish assemblages in three microbasins in the Upper Paraná River Basin / Influência da urbanização em assembleias de peixes de riachos em três microbacias na bacia do Alto Rio Paraná

The colonization pattern of fish assemblages in streams is often studied in the context of environmental filters. On the other hand, when fish assemblages are subjected to anthropogenic effects, variables associated with environmental quality assume more importance. Therefore, this work evaluated the richness and composition of fish from streams sampled at different urbanization levels, aiming to determine any direct effects on the structure of fish assemblages. To accomplish this, samples were collected from 2003 to 2011 at 31 sites distributed among 3 microbasins in the Rio Ivinhema Basin, Alto Rio Paraná. Based on environmental variables, physicochemical of the water and analysis of the use and occupation of the soil, the microbasins were classified into different urbanization levels (low, medium and high). A total of 4,320 individuals were sampled, out of which 57 fish species were recorded. Sampled sites with medium urbanization level presented higher richness compared to sampled sites with high urbanization level which presented lower richness. Species richness in these sites was explained mainly by water temperature and water velocity. Results confirmed that urbanization does directly affect environmental integrity, which, in turn, can lead to the homogenization of stream assemblages.

Estudos sobre assembleias de peixes em riachos enfatizam o papel dos filtros ambientais associados ao padrão de colonização das assembleias, por outro lado, quando a assembleia está sujeita aos efeitos antropogênicos, as variáveis ambientais associadas à qualidade ambiental assumem maior importância. Dessa forma, o objetivo deste estudo foi analisar a riqueza e a composição de peixes de riachos amostrados em diferentes níveis de urbanização, buscando evidenciar se o efeito reflete diretamente na estrutura das assembleias. As amostragens foram realizadas em 31 locais distribuídos em três microbacias na bacia Rio Ivinhema, Alto Rio Paraná, no período de 2003 a 2011. Com base nas variáveis ambientais, físico-químicos da água e análise do uso e ocupação do solo as microbacias foram classificadas em diferentes níveis de urbanização (baixo, médio e alto). Foram amostrados um total 4.320 indivíduos, dos quais foram registradas 57 espécies de peixes. Os locais amostrados com influência média da urbanização apresentaram maior riqueza de espécies, entretanto, os locais amostrados com alta influência da urbanização apresentaram menor riqueza de espécies. Dessa forma, constatamos que a urbanização influencia diretamente na integridade ambiental, que pode levar a homogeneização das assembleias de riachos.

Influence of urbanization on stream fish assemblages in three microbasins in the Upper Paraná River Basin

Abstract The colonization pattern of fish assemblages in streams is often studied in the context of environmental filters. On the other hand, when fish assemblages are subjected to anthropogenic effects, variables associated with environmental quality assume more importance. Therefore, this work evaluated the richness and composition of fish from streams sampled at different urbanization levels, aiming to determine any direct effects on the structure of fish assemblages. To accomplish this, samples were collected from 2003 to 2011 at 31 sites distributed among 3 microbasins in the Rio Ivinhema Basin, Alto Rio Paraná. Based on environmental variables, physicochemical of the water and analysis of the use and occupation of the soil, the microbasins were classified into different urbanization levels (low, medium and high). A total of 4,320 individuals were sampled, out of which 57 fish species were recorded. Sampled sites with medium urbanization level presented higher richness compared to sampled sites with high urbanization level which presented lower richness. Species richness in these sites was explained mainly by water temperature and water velocity. Results confirmed that urbanization does directly affect environmental integrity, which, in turn, can lead to the homogenization of stream assemblages.

Resumo Estudos sobre assembleias de peixes em riachos enfatizam o papel dos filtros ambientais associados ao padrão de colonização das assembleias, por outro lado, quando a assembleia está sujeita aos efeitos antropogênicos, as variáveis ambientais associadas à qualidade ambiental assumem maior importância. Dessa forma, o objetivo deste estudo foi analisar a riqueza e a composição de peixes de riachos amostrados em diferentes níveis de urbanização, buscando evidenciar se o efeito reflete diretamente na estrutura das assembleias. As amostragens foram realizadas em 31 locais distribuídos em três microbacias na bacia Rio Ivinhema, Alto Rio Paraná, no período de 2003 a 2011. Com base nas variáveis ambientais, físico-químicos da água e análise do uso e ocupação do solo as microbacias foram classificadas em diferentes níveis de urbanização (baixo, médio e alto). Foram amostrados um total 4.320 indivíduos, dos quais foram registradas 57 espécies de peixes. Os locais amostrados com influência média da urbanização apresentaram maior riqueza de espécies, entretanto, os locais amostrados com alta influência da urbanização apresentaram menor riqueza de espécies. Dessa forma, constatamos que a urbanização influencia diretamente na integridade ambiental, que pode levar a homogeneização das assembleias de riachos.

Bat (Mammalia: Chiroptera) biodiversity in a subtropical inselberg ecosystem of Northeastern Argentina / Biodiversidad de murciélagos (Mammalia: Chiroptera) en un ecosistema inselberg subtropical del Noreste de Argentina

Abstract Introduction: Rocky outcrops influence both micro and macro habitat for plants and animals by increasing the availability and predictability of food, providing shelter, and unique microclimatic conditions. Objective: We describe the bat assemblage in three isolated rocky outcrops and their surrounding pediments, adding new data about trophic guilds and roosts. Methods: We surveyed the bat fauna of Paraje Tres Cerros, Corrientes Province, Argentina, exploring 13 sites during 26 field trips, using mist nets and search of roosts. We made an accumulation species curve and calculate inventory completeness. The similarity and composition of different habitats was compared by a Non-Metric Multidimensional Scaling (NMDS) and an ANOSIM test. Results: We reported 13 species, with a completeness inventory of the 80 % (Jacknife1), corresponding to the families Vespertilionidae, Molossidae and Phyllostomidae. The insectivorous bats were the best represented guild. We found nine types of roost for eight species in different sites. The analysis expressed low differences in the species composition between both types of habitats in the area. Conclusions: The rocky outcrops and their pediments are important ecosystems for the conservation and diversity of the bats in the region, since their assemblages are regionally unique.

Resumen Introducción: Los afloramientos rocosos influyen tanto en el micro como en el macro hábitat de plantas y animales al incrementar la disponibilidad de alimentos, proporcionar refugios y brindar condiciones microclimáticas únicas. Objetivo: Describir el ensamble de murciélagos en tres afloramientos rocosos aislados y sus pendientes circundantes, incorporando nuevos datos sobre gremios tróficos y refugios. Métodos: Muestreamos la fauna de murciélagos del Paraje Tres Cerros, provincia de Corrientes, Argentina, exploramos 13 sitios durante 26 viajes de campo, usando redes de niebla y búsqueda de refugios. Realizamos una curva de acumulación de especies y calculamos la completitud del inventario. La similitud y composición de diferentes hábitats se comparó mediante un escalado multidimensional no métrico (NMDS) y una prueba ANOSIM. Resultados: Reportamos 13 especies, con una completitud del 80 % del inventario (Jacknife1), correspondientes a las familias Vespertilionidae, Molossidae y Phyllostomidae. Los gremios mejor representados fueron los insectívoros. Encontramos nueve tipos de refugios para ocho especies en diferentes sitios. Los análisis expresaron bajas diferencias en la composición de especies entre ambos tipos de hábitats en el área. Conclusión: Los afloramientos rocosos y pendientes son ecosistemas importantes para la conservación y diversidad de los murciélagos en la región, ya que sus comunidades son regionalmente únicas.

Frugivorous bat (Chiroptera: Phyllostomidae) community structure and trophic relations in Atlantic Forest fragments

We evaluated the structure of a community of frugivorous bats using composition and abundance patterns, niche amplitude and food overlap of these animals in four Atlantic Forest fragments, each one exposed to different conservation realities. For twelve months, we captured six bat species and found the seeds of 13 species of pioneering plants in 158 fecal samples. The most abundant bat species were Artibeus planirostris (25.4%), Artibeus lituratus (24.1%) and Carollia perspicillata(23.9%). Only one fragment (Fazenda Unida), the most conserved area, exhibited a significantly different composition and abundance of species. We found low trophic niche amplitude values (<0.60), associated to high food overlaps. Our results suggest that bats can adjust their foraging strategy to deal with food availability variations. By favoring pioneering plant species, the fragmentation process noted of the studied areas creates an attractive environment for bats more tolerant to this type of disturbance. The sampled areas represent important secondary forest remnants in southern Brazil that require attention to avoid an even greater loss of bat diversity.

Decisiones médicas en enfermedades raras: de su definición estadística a su comprensión social / Medical decisions in rare diseases: from their statistical definition to their social understanding

Resumen Este ensayo teórico pretende analizar las decisiones médicas en el caso de las enfermedades raras. Una decisión médica es un proceso que orienta la producción de un diagnóstico o un tratamiento de salud, utilizando la información y evidencia disponible, en el cual muchas veces se incorporan las preferencias de los pacientes. En el caso de las enfermedades comunes o frecuentes, existe información clara y disponible sobre las distintas alternativas frente a un problema de salud. En el caso de las enfermedades raras, que están estadísticamente definidas como aquellas patologías que tienen prevalencia inferior a 1:2000, no suelen existir tales alternativas. Por la cronicidad y gravedad que este tipo de patologías suelen revestir, la ausencia de posibilidades se convierte en un problema que tiene dimensiones sanitarias y sociales. En este sentido, este artículo propone una transición de una definición estadística de las enfermedades a una definición social, que permita a futuras investigaciones conocer y profundizar en los procesos y efectos sanitarios, psicológicos y sociales sobre las enfermedades raras y su padecimiento.

Abstract The following article is a theoretical work on medical decisions in the case of rare diseases. A medical decision is a process that guides the production of a health diagnosis or treatment, using the available information and evidence, where the preferences of the patients are often incorporated. In the case of common or frequent illnesses, patients usually have clear and available information on the different alternatives to a health problem. In the case of rare diseases, which are statistically defined as those pathologies with a prevalence of less than 1:2000, usually there are no such alternatives. Due to the chronicity and severity that these types of pathologies have, the absence of possibilities becomes a problem that has health and social dimensions. In this sense, the article below proposes a transition from a statistical definition of diseases to a social definition that allows future research to learn about and deepen the health, psychological and social processes and effects on rare diseases and their condition.

Macroinvertebrados acuáticos en arroyos asociados con bofedales altoandinos, Ayacucho Perú

Introducción: Los arroyos asociados a bofedales se hallan en ambientes donde las condiciones son extremas con temperaturas muy variables, baja presión atmosférica e intensa radiación solar. Sin embargo, existen ensamblajes de macroinvertebrados asociados a estos ambientes, cuya información es escasa. A escala global y regional, las características de los macroinvertebrados cambian con el aumento de la latitud y altitud (disminución de la riqueza y variación de la composición). A nivel local, también se puede agregar el efecto de las aguas ácidas y de elevada conductividad proveniente de manantiales que se unen a los arroyos, que generan heterogeneidad en la calidad de agua y consecuentemente en las características de los macroinvertebrados. Objetivo: Comparar la diversidad, composición y abundancia de macroinvertebrados y las características fisicoquímicas del agua de arroyos asociados a dos bofedales altoandinos, ubicados en el departamento de Ayacucho, Perú. Metodología: Se estudiaron once estaciones ubicados en arroyos de dos bofedales: 7 en Guitarrachayocc (G) de 43 ha (n = 28) y 4 en Pichccahuasi (P) de 28 ha (n = 8). Se empleó una red de Surber (0.3 mm de malla, área de muestreo de 1 200 cm2), para realizar muestreos mensuales de octubre de 2016 a abril de 2017. Análisis de componentes principales (PCA) y análisis de varianza multivariante no paramétrico (NP-MANOVA) se aplicaron para comparar las características del agua. Además, se utilizó un análisis de coordenadas principales (PCoA) y NP-MANOVA para comparar el ensamblaje. La prueba no paramétrica de Kruskal-Wallis (α = 0.05) se utilizó para comparar las abundancias absolutas de los taxa principales. Resultados: Las características del agua fueron heterogéneas, con pH de 3.2 (± 0.4) a 7.6 (± 0.1), conductividad de 168.9 (± 91) µS/cm a 1 117 (± 159.3) µS/cm; diferencias que fueron significativas (p < 0.05) al comparar las estaciones de muestreo, donde el agua de G6 presenta los mínimos valores de pH y los máximos de conductividad, al igual que cloruros. Se recolectaron un total de 8 126 individuos, distribuidos en 26 taxa de 20 familias, 11 órdenes y cinco clases. Los insectos fueron el grupo más diverso y abundante. A pesar a la cercanía de los arroyos de los bofedales, presentaron diferencias: en G, se registró 25 taxa, con dominancia de Macrelmis sp., Dicrotendipes sp., Claudioperla sp., Meridialaris sp. y en P, 9, con dominancia de Pedrowygomya sp., Hyalella sp. y Dicrotendipes sp. La densidad fue de 475 ind./m2 y de 31 ind./m2 para el bofedal G y P respectivamente, estos valores fueron estadísticamente diferentes (p < 0.05). El PCoA y el PCA confirmados por NP-MANOVA mostraron que G6 es diferente (p < 0.05) dentro de G porque recibe el aporte de agua de un manantial. Conclusiones: La riqueza, composición y densidad de los macroinvertebrados son diferentes en los arroyos según el bofedal al cual se halla asociado. La contribución de los manantiales a los arroyos genera cambios drásticos en la calidad del agua y los macroinvertebrados, determinando la formación de ensamblajes con diferente riqueza y estructura.

Introduction: Streams associated with high Andean wetlands are found in environments where conditions are extreme, highly variable temperature, low atmospheric pressure, intense solar radiation. The macroinvertebrate assemblages have been poorly studied compared to streams located at lower altitudes. On a global and regional scale, the characteristics of macroinvertebrates change with the increase in latitude and altitude (decreasing in richness and variation in composition). At the local level, the effect of acidic waters with high conductivity from springs that join streams generate heterogeneity in water quality and consequently in the characteristics of macroinvertebrate structure. Objective: To compare the diversity, composition and abundance of macroinvertebrates and the physicochemical characteristics of stream water in two high Andean wetlands in Peru. Methodology: Eleven stations located in streams of two high Andean wetlands were studied: 7 in Guitarrachayocc (G) of 43 ha (n = 28) and 4 in Pichccahuasi (P) of 28 ha (n = 8). A Surber sampler (0.3 mm mesh, sampling area of 1 200 cm2) was used to carry out monthly samplings from October 2016 to April 2017. Principal Component Analysis (PCA) and Non-Parametric-Multivariate-Analysis-Of-Variance (NP-MANOVA) were applied to compare water characteristics. The macroinvertebrate assemblages from the two streams were compared by using a Principal coordinate analysis (PCoA), NP-MANOVA, and a non-parametric Kruskal-Wallis test (α = 0.05). Results: The characteristics of the water were heterogeneous, with significant differences in pH which ranged from 3.2 (± 0.4) to 7.6 (± 0.1) and conductivity ranging from 168.9 (± 91.0) µS / cm to 1 117.0 (± 159.3) µS / cm. In particular, G6 presented the lowest pH values and the highest electrical conductivity, as well as chlorides. A total of 8 126 individuals were collected, distributed in 26 taxa from 20 families, 11 orders and five classes. Insects were the most diverse and abundant group. Differences were found between the streams of the highland wetlands, despite their proximity: in G, 25 taxa were registered, with a dominance of Macrelmis sp., Dicrotendipes sp., Claudioperla sp. and Meridialaris sp. and in P, 9, with a dominance of Pedrowygomya sp., Hyalella sp. and Dicrotendipes sp. The density was 475 ind./m2 and 31 ind./m2 for G and P respectively, these values were statistically different (p < 0.05). The PCoA and PCA confirmed by NP-MANOVA showed that G6 was different (p < 0.05) within G because it receives water contribution from a spring. Conclusions: The richness, composition and density of macroinvertebrates were different in streams depending on the bofedal with which it is associated. The contribution of the springs to the streams generates drastic changes in the quality of the water and the macroinvertebrates, determining the formation of assemblages with different richness and structure.

Variación estacional y características fisicoquímicas e hidrológicas que influyen en los macroinvertebrados acuáticos, en un río tropical

Introducción: La distribución de los macroinvertebrados acuáticos en los ríos puede estar determinada por el tipo del sustrato, la forma del canal del río, el régimen hidrológico y las interacciones con factores bióticos y abióticos. En Costa Rica se desconoce en gran parte de los ríos, las variaciones en la distribución de los macroinvertebrados acuáticos producto de las transiciones y consecuentes variaciones en características fisicoquímicas e hidrológicas. Objetivos : 1) Estudiar el cambio del ensamblaje de macroinvertebrados acuáticos en dos sitios dentro del cauce del Río Naranjo, durante los cuatro periodos hidrológicos del año; 2) determinar la relación entre las variables fisicoquímicas, sustrato y el caudal con el ensamblaje. Metodología: El estudio se realizó en el Río Naranjo, Costa Rica, en dos sitios de muestreo durante un año, evaluando los cuatro periodos hidrológicos del año. En cada sitio de muestreo se obtuvieron valores de velocidad y profundidad del agua, caudal, oxígeno disuelto, pH, conductividad, sulfatos, amonio, nitrato, silicatos, fosfatos y sustrato, y se obtuvo una muestra de macroinvertebrados acuáticos por cada tipo de microhábitat determinado por la velocidad del agua. Se realizó una prueba PERMANOVA de dos vías, para determinar si existe una diferencia entre la abundancia de macroinvertebrados acuáticos, por periodo y entre sitios. Se hizo un análisis de correspondencia canónica para observar la relación entre los macroinvertebrados acuáticos y los factores ambientales. Por último, se realizó una prueba de Spearman para determinar la relación positiva o negativa de las variables con los macroinvertebrados Resultados: Hubo una mayor abundancia durante la estación seca, mientras que durante la transición de la estación seca a la lluviosa se registró la menor abundancia de organismos. El ACC indicó que el primer eje presentó una relación positiva con el sustrato limo y arena, y una relación negativa para las variables velocidad de corriente y sustrato rocoso. El segundo eje presentó una relación positiva con el caudal y los nitratos, y negativa para el sustrato canto rodado. La mayoría de los organismos mostraron una respuesta negativa al aumento del flujo y los nitratos. Discusión: Conforme aumenta el caudal, aumenta la velocidad del agua y no todos los organismos registrados en el Río Naranjo cuentan con características para sobrevivir a estas condiciones. Además, la profundidad también aumenta junto con la fuerza de arrastre, provocando el movimiento de los sustratos de menor tamaño y una remoción de organismos. El aumento de nitratos puede generar una disminución de los organismos más sensibles como Plecoptera y Ephemeroptera. A pesar de las variaciones fisicoquímicas y de caudal registradas en el Río Naranjo, éstas no fueron lo suficientemente fuertes como para variar el ensamblaje de macroinvertebrados acuáticos, por lo que la cuenca por el momento no cuenta con factores estresantes que elimine organismos durante uno o varios meses del año.

Introduction: The distribution of aquatic macroinvertebrates in rivers may be determined by the type of substrate, the shape of the river channel, the hydrological regime, and interactions with biotic and abiotic factors. Variations in the distribution of aquatic macroinvertebrates due to transitions and variations in physicochemical and hydrological characteristics are unknown in most rivers. Objectives: 1) to study the change in the aquatic macroinvertebrates assemblages in two sites in Naranjo River, during the four hydrological seasons; 2) to determine the relationship between the physicochemical variables, substrate and flow with the assemblages. Methodology: The study was conducted in the Naranjo River, Costa Rica, at two sampling sites during one year, evaluating the four seasons of the year. In each station we measure, values of water velocity and depth, flow rate, dissolved oxygen, pH, conductivity, sulfates, ammonium, nitrate, silicates, phosphates, and substrate were obtained, and a sample of aquatic macroinvertebrates was obtained for each type of microhabitat determined by water velocity. Two-way PERMANOVA was made to determine if there is a difference among aquatic macroinvertebrate abundance, per period and between sites. Canonical correspondence analysis was used to observe the relationship between aquatic macroinvertebrates and environmental factors. Finally, a Spearman's rank correlation coefficient was performed to determine the positive or negative relationship of variables with macroinvertebrates. Results: There was a greater abundance during the dry season, while during the transition from dry to the rainy season, the lowest abundance of organisms was recorded. The CCA indicates that the first axis presented a positive relationship with the silt and sand substrate and a negative relationship for the current velocity and rock substrate variables. The second axis showed a positive relationship with flow and nitrates and negative for the pebble substrate. Most organisms showed a negative response to increased flow and nitrates. Discussion: As flow increases, current velocity increases, and not all organisms recorded in the Naranjo River have the characteristics to survive these conditions. In addition, the depth also increases along with the drag force, causing movement of smaller substrates and removal of organisms. Increased nitrates can lead to a decrease in more sensitive organisms, such as Plecoptera and Ephemeroptera. In spite of the physicochemical and flow variations registered in the Naranjo River, these were not strong enough to vary the assemblages of aquatic macroinvertebrates, so the basin does not have stressful factors that eliminate organisms during one or several months of the year.

Temporal patterns of fish occurrence of the euryhaline sector of a subtropical estuary, southern Brazil

Fish fauna was studied in five sites of the shallow infralittoral of the Paranaguá Bay during the period from October 1999 to September 2000. At each sampling site, fish were sampled with other trawls, salinity and temperature were measured, water samples were taken from the bottom of the water column for determination of dissolved oxygen, dissolved inorganic nitrogen and phosphate. The spatial and temporal behavior of the environmental variables was analyzed by a Principal Component Analysis; Cluster Analysis was used to gather the sampling sites, and Factorial Correspondence Analysis was applied to the most abundant species. Temperature was themost important variable for the distribution of the months, allowing the division of the study period into hot and cold months. The temporal variation in the fish fauna composition was indicated by cluster analysis, with highest percentages of dissimilarity between the sampling sites during hot months. The variation in dissimilarity between the sites occurred due to differences in the number of individuals and species of the catches. The high frequencies of occurrence of Anisotremus surinamensis, Etropus crossotus, Genidens genidens, Micropogonias furnieri and Sphoeroides greeleyiwere related to high temperatures. The greatest number of fish and species observed in hot months may be related to the life cycle of many species, which reproduce in warmer months, and whose offspring use estuaries as breeding areas.

Diatom assemblages associated with turtle carapaces in the Neotropical region / Diatomeas epizoicas de los caparazones de tortugas de la región Neotropical

Abstract Few studies have explored the ecology and interrelationship with other organisms of the many endangered freshwater turtle species inhabiting the Neotropical region. The focus of the current study was to shed light on the relationship between Neotropical turtle carapaces and primary producers, insofar as the surface of former constitutes a suitable substrate for the colonization and establishment of the latter. The under-explored relationship between turtle carapaces and the diatom assemblages inhabiting them was investigated and characterized in terms of taxonomic and biological traits (bio-volume, life-form, and attachment). The carapaces of seven native turtle species were surveyed. Among these carapaces, a total of 45 diatom taxa were found, and diatom taxa varied among turtle species. Podocnemis vogli and Podocnemis expansa supported more diverse diatom assemblages than Podocnemis lewyana, Rhinoclemmys diademata, and Rhinoclemmys melanosterna, which were dominated by Navicula spp. Analysis, further showed that carapace size did not explain differences in diatom diversity. However, a trait-based analysis suggests that both carapace roughness and an assemblage's successional stage might explain the differences in assemblage composition. Because turtles can serve as dispersal vectors, characterizing their epibiont diatom assemblages may contribute to our understanding of diatom distribution on larger scales, as well as, give us some clues as to the auto-ecology of turtles that help us to effectively determine conservation areas for these endangered species.(AU)

Resumen De las especies de tortugas en estado crítico o vulnerable de conservación que habitan en la región Neotropical, son pocos los estudios que han ahondado en su ecología o relaciones con otros tipos de organismos. El presente estudio buscó caracterizar la asociación existente entre las diatomeas y el caparazón de especies de tortugas neotropicales, ya que este representa un sustrato adecuado para la colonización y establecimiento de este grupo de algas. Esta asociación fue estudiada considerando tanto la composición de especies como la de rasgos biológicos (biovolumen, forma de vida, y forma de adherencia) de la comunidad de diatomeas. En los caparazones de las 7 especies de tortugas muestreadas se encontraron un total de 45 táxones. La composición de táxones varió entre los caparazones de las especies. Se encontró una mayor diversidad en los caparazones de Podocnemis vogli y Podocnemis expansa, mientras que en Podocnemis lewyana, Rhinoclemmys diademata, y Rhinoclemmys melanosterna se encontró una comunidad de baja diversidad dominada principalmente por Navicula sp. Los resultados sugirieron que la rugosidad del caparazón junto al estado de la sucesión pueden explicar las diferencias observadas en la composición de táxones de los diferentes caparazones. Debido a que las tortugas pueden funcionar como vectores de dispersión, caracterizar las comunidades que pueden crecer sobre sus caparazones podría contribuir a entender la distribución de las diatomeas a escalas mayores. Además, esta caracterización podría darnos pistas clave para la delimitación de áreas de conservación efectivas para las especies más amenazadas.(AU)

Relaciones entre la diversidad de aves y la estructura de vegetación en cuatro etapas sucesionales de bosque secundario, antioquia, colombia / Relationships between bird diversity and vegetation structure in four secondary forest successional stages, antioquia, colombia

RESUMEN Se estudió la relación entre la diversidad taxonómica y funcional del ensamblaje de aves y la estructura de vegetación, en cuatro estadios de sucesión secundaria de bosque, realizando cinco muestreos, entre junio de 2016 y febrero de 2017, en los que se registraron las aves, mediante puntos de conteo de radio fijo y se caracterizó la estructura de la vegetación de cada sucesión. Se estableció la abundancia, la preferencia, la especificidad de hábitat y el gremio trófico, así como la riqueza y la diversidad de las especies de aves y las relaciones entre la composición de las especies y los gremios tróficos con las variables del hábitat. Se registraron 9.516 individuos de 187 especies, pertenecientes a 42 familias y 15 órdenes. Se determinaron dos agrupaciones, separando los estadios sucesionales SS1 y SS2, de los estadios SS3 y SS4, con una similitud entre los dos grupos del 10%, a nivel taxonómico y del 32%, a nivel funcional. La regeneración natural posterior al abandono de prácticas agropecuarias, permiten un incremento de áreas de bosque secundario que, en la medida en que obtienen mayor complejidad estructural, se asocian con una mayor cantidad de especies con preferencia de hábitat de interior de bosque y un aumento de los gremios tróficos nectarívos y frugívoros.

ABSTRACT The relationships between taxonomic and functional diversity of bird assemblage and vegetation structure in four stages of secondary forest succession were studied. Five field samplings were carried out between June 2016 and February 2017, in which birds were recorded using fixed radius point counts, and the vegetation structure of each successional stage was characterized. Bird species were identified and their habitat preference, specificity and trophic guilds were established. The abundance, preference, habitat specificity and trophic guild, and the richness and diversity of species of birds and relationships between species composition and trophic guilds with habitat variables in the four sequences was established. 9516 individuals from 187 bird species belonging to 42 families and 15 orders were registered. Two clusters separating the SS1 and SS2 of SS3 and SS4 successional stages, were determined, with a similarity between both of 10% at taxonomic level and 32% at functional level. The natural regeneration subsequent to the abandonment of agricultural practices allow an increase in secondary forest areas, which to the extent they get greater structural complexity, are associated with increased number of forest interior species, and an increase of nectarivorous and frugivorous guilds.

Influence of sediment granulometry and salinity on the composition of an estuarine fish assemblage in the Mexican Tropical Pacific / Influencia de la granulometría del sedimento y la salinidad en la composición de una comunidad de peces estuarinos en el Pacífico tropical mexicano

Abstract Barra de Navidad lagoon (BNL) is one of the main coastal wetlands in the coast of the State of Jalisco, Mexico. It is a Ramsar site (wetland of international importance) and has been included among the 81 mangrove sites with biological relevance and ecological rehabilitation needs in Mexico. Although fish fauna composition is well known in BNL, little evidence exists that support seasonal and spatial changes of fish assemblages' structure. The hypothesis tested in this study was that there are significant seasonal and spatial changes in BNL fish assemblages' composition which can be explained, at least partially, by changes in salinity, water temperature and sediment's granulometry. Fish assemblages were sampled monthly from October 2012 to September 2013 at four zones of BNL, using gill nets (7.62 mm stretched mesh). A sample was taken every month in a randomly selected area of each zone. Prior to each sampling operation, water salinity and temperature were measured using an YSI-30 probe. Samples of sediment were collected with a Van Veen grab sampler in three randomly selected points of each zone for granulometry and organic matter analyses. A total of 2 026 individuals belonging to 48 species were collected. Slightly more than 90 % of all caught fish belonged to nine species: Peruvian mojarra (Diapterus brevirostris), Pacific crevalle-jack (Caranx caninus), White mullet (Mugil curema), Blue sea-catfish (Ariopsis guatemalensis), Oval flounder (Syacium ovale), Pacific lined sole (Achirus mazatlanus), Yellowfin mojarra (Gerres simillimus), Pacific bumper (Chloroscombrus orqueta) and Freckled porcupinefish (Diodon holocanthus). Generalized linear models yielded significant differences among zones for the mean abundance of each of these nine species, but only in two cases seasonal differences were significant (D. brevisrostris and C. caninus). Permutational multivariate analysis of variance yielded also significant differences among zones and between seasons for the composition of the fish assemblage. Redundancy analysis using salinity, temperature, and percentage mud in sediment as environmental variables showed that fish assemblage's composition varies along two main gradients defined by mud fraction of sediments in a small spatial scale (~ 3 km) and salinity in a seasonal scale. Percentage of variation explained by canonical axes was less than 25 %, indicating that other factors could be influencing changes in assemblage composition. As most species appear as juveniles in the lagoon, fluctuations in their abundances could be linked, at least partially, with recruitment events. Rev. Biol. Trop. 66(3): 1065-1077. Epub 2018 September 01.

Resumen La laguna Barra de Navidad (LBN) es uno de los principales humedales costeros en la costa del Estado de Jalisco, México. Es un sitio Ramsar (humedal de importancia internacional) y ha sido incluida entre los 81 sitios de manglar con relevancia biológica y necesidades de rehabilitación en México. Aunque la composición de la ictiofauna es bien conocida en LBN, hay poca evidencia sobre la existencia de cambios estacionales y espaciales en la estructura de la misma. La hipótesis que guió este trabajo fue que en la composición de la ictiofauna de la laguna Barra de Navidad hay cambios espaciales y estacionales que pueden ser explicados, al menos parcialmente, por cambios en la salinidad, temperatura del agua y granulometría del sedimento. Los peces fueron muestreados mensualmente de octubre 2012 a septiembre 2013 en cuatro zonas de la laguna, usando redes agalleras (7.62 mm de malla estirada). Se tomó una muestra cada mes en un área seleccionada aleatoriamente en cada zona. Previo a cada operación de muestreo, se midieron la salinidad y la temperatura del agua con una sonda YSI-30. Muestras de sedimento para análisis granulométrico y del contenido de materia orgánica, se recolectaron con una draga tipo Van Veen en tres puntos seleccionados aleatoriamente en cada zona. Se recolectaron 2 026 individuos de 48 especies de peces. Poco más de 90 % de todos los peces contados pertenecieron a nueve especies: Diapterus brevirostris, Caranx caninus, Mugil curema, Ariopsis guatemalensis, Syacium ovale, Achirus mazatlanus, Gerres simillimus, Chloroscombrus orqueta y Diodon holocanthus. Modelos lineales generalizados arrojaron diferencias significativas entre zonas para la abundancia media de estas nueve especies, pero solo en dos casos se encontraron diferencias significativas entre estaciones (D. brevirostris y C. caninus). El análisis multidimensional de varianza basado en permutaciones, arrojó también diferencias significativas entre zonas y entre estaciones para la composición de la ictiofauna. El análisis de redundancia usando la salinidad, la temperatura y el porcentaje de lodo en el sedimento como variables ambientales, mostró que la composición de la ictiofauna varía a lo largo de dos gradientes definidos por la fracción de lodo de los sedimentos en una escala espacial pequeña (~ 3 km) y la salinidad en una escala estacional. El porcentaje de variación explicado por los ejes canónicos fue menor de 25 %, indicando que otros factores pudieran influir en los cambios de la composición de la ictiofauna. Como la mayoría de las especies aparecen en su estadio juvenil en la laguna, las fluctuaciones en sus abundancias pudieran estar relacionadas, al menos parcialmente, con eventos de reclutamiento.

Fish beta diversity responses to environmental heterogeneity and flood pulses are different according to reproductive guild

In floodplain communities, beta diversity is influenced by different factors; however, environmental heterogeneity and floods are believed to be particularly influential. The influence of environmental heterogeneity and floods on beta diversity may vary among guilds that present different ecological traits. This study evaluated the correlation between the environmental heterogeneity and flood periods and the beta diversity of trophic and reproductive guilds of fish assemblages. Sampling was conducted quarterly between 2000 and 2012 in the upper Paraná River floodplain. The environmental heterogeneity and period (i.e., dry or flood) were associated with the beta diversity of each guild based on the results of generalized least squares linear models. Only guilds with parental care were influenced by the interaction between environmental heterogeneity and period. The beta diversity of the other guilds presented no relationship between environmental heterogeneity and period. It is likely that species with parental care presented less dispersal capacity, which increased the dissimilarity among assemblages. The higher dispersion rates of the other guilds may be responsible for the lack of relationship between the beta diversity and the environmental heterogeneity and period. In sum, these results suggest that reproductive guilds influence how environmental heterogeneity and floods affect beta diversity variation.(AU)

A diversidade beta é influenciada por diferentes fatores em comunidades de planícies de inundação; contudo, acredita-se que a heterogeneidade ambiental e inundações sejam particularmente influentes. A influência da heterogeneidade ambiental e inundações na diversidade beta podem variar entre guildas que apresentam diferentes características ecológicas. Este estudo avaliou a correlação entre heterogeneidade ambiental, os períodos de inundação e a diversidade beta de guildas tróficas e reprodutivas de peixes. A amostragem foi realizada trimestralmente entre 2000 e 2012 na planície de inundação do Alto rio Paraná. Heterogeneidade ambiental e o período (i.e., seca ou cheia) foram associados à diversidade beta de cada guilda por modelos lineares de quadrados mínimos generalizados. Somente guildas com cuidados parentais foram influenciadas pela interação entre heterogeneidade ambiental e período. A diversidade beta das outras guildas não apresentou relação com heterogeneidade ambiental e período. É provável que espécies com cuidados parentais apresentem menor capacidade de dispersão, o que aumenta a diferença entre as assembleias. As maiores taxas de dispersão de outras guildas podem ser responsáveis pela ausência de relação entre a diversidade beta e heterogeneidade ambiental e o período. Em suma, os resultados sugerem que as guildas reprodutivas influenciam a forma como a heterogeneidade ambiental e as inundações afetam a variação da diversidade beta.(AU)

Singularización y clínica. Contrapunto en torno a la noción de producción en el dispositivo analítico / Singularization and clinic. Counterpoint around the notion of production in the analytical device

En este trabajo se problematiza qué se podría entender por producción en dispositivos clínicos. A través de un contrapunto entre desarrollos teóricos de Jaques Lacan y de Gilles Deleuze y Félix Guattari, se hace foco en dos cuestiones: la primar es establecer una tensión entre modos de concebir la materialidad sobre la que se operaría en dichos dispositivos. Se propone que para el psicoanalista francés se trabaja, a través del equívoco, sobre lo simbólico, mientras que para los autores de El antiedipo la labor cartográfica recae sobre la materia heterogénea del plano de consistencia. La segunda interroga la idea de fin de análisis: el contrapunto se da entre la idea lacaniana de producción de un resto des-subjetivado que realiza la división del sujeto, del que pasante daría testimonio ante un jurado en la Escuela, y el pensar la producción, con nociones de Deleuze y Guattari, en tanto que movimientos de desterritorialización - reterritorialización en el devenir de una vida. A la luz de esa problematización sobre la producción en la experiencia psicoanalítica, se propone pensar la labor a la que ahí se dispone como un proceso, siempre inacabado, de singularización.

This paper problematizes what could be understood for production in clinical devices. Through a counterpoint between theoretical developments of Jaques Lacan and Gilles Deleuze and Felix Guattari, we will focus on two issues: the first one is to establish a tension between ways of conceiving the materiality on which operate that devices. It is proposed that the French psychoanalyst works, through the equivocality, on the symbolic, while for the authors of The Anti-Oedipus the cartographic work falls on the heterogeneous material of the plane of consistency. The second issue questions the idea of analysis ending: the counterpoint is between the Lacanian idea of producing a rest des-subjectivized that realises the division of the subject, of which the passant testify in front of the jury of the School, and thinking production with notions of Deleuze and Guattari, as movements of deterritorialization - reterritorialization in the course of a life. In light of that problematization on production in the psychoanalytic experience, it intends to think the work to which there is disposed as a process, always unfinished, of singularization.

Detection of zoonotic and livestock-specific assemblages of Giardia duodenalis in free-living wild lizards / Detecção de genótipos de Giardia duodenalis zoonóticos e específicos de ruminantes domésticos em lagartos selvagens

Abstract Giardia duodenalis is a zoonotic parasite that infects the gut of a wide range of vertebrates, including numerous wildlife species. However, little is known about this protozoan parasite in reptiles. Fecal samples from 31 wild lizards were collected in Galicia (northwest Spain) and screened for the presence of Giardia by PCR amplification and sequencing of the ITS1-5.8S-ITS2 region in the ribosomal unit. This allowed detection of the parasite in 5 samples (16.1%), and enabled identification of G. duodenalis assemblage A2 in two samples of Iberian rock lizard (Iberolacerta monticola), G. duodenalis assemblage B in other two samples of I. monticola, and G. duodenalis assemblage E in one sample of Bocage's wall lizard (Podarcis bocagei). The results obtained after PCR amplification and sequencing of the SSU-rDNA gene confirmed the presence of G. duodenalis assemblage A in two samples of I. monticola. This is the first report of G. duodenalis in free-living lizards, although further studies are needed to distinguish between actual infection and mechanical dissemination of cysts. The detection of zoonotic and livestock-specific assemblages of G. duodenalis demonstrates the wide environmental contamination by this parasite, possibly due to human activities.

Resumo Giardia duodenalis é um parasito zoonótico que infecta o intestino delgado de uma ampla gama de vertebrados, sendo detectado em numerosas espécies selvagens. No entanto, pouco se conhece sobre a presença deste parasito protozoário em répteis. Para estudar a presença de Giardia, foram obtidas amostras fecais provenientes de 31 lagartos e coletadas em diferentes localizações de Galicia (Noroeste da Espanha). Mediante a aplicação da técnica de PCR e posterior sequenciamento da região ITS1-5.8S-ITS2 da unidade ribossômica, detectou-se Giardia em 5 amostras (16,1%), identificando-se o genótipo A2 de G. duodenalis em 2 amostras de lagartos da montanha (Iberolacerta monticola), G. duodenalis genótipo B em outras 2 amostras de I. monticola e G. duodenalis genótipo E em outra amostra de lagarto de Bocage (Podarcis bocagei). Os resultados obtidos, após amplificação e sequenciamento de um fragmento do gene SSU-rDNA, confirmam a presença de G. duodenalis genótipo A em 2 amostras de I. monticola. Esta é a primeira vez que se descreve G. duodenalis em lagartos selvagens, embora sejam necessários outros estudos complementares para confirmar se estes animais sofrem uma infecção real ou se apenas atuam como disseminadores mecânicos da contaminação ambiental. Além disso, a detecção de genótipos zoonóticos e específicos de ruminantes domésticos demonstra a contaminação do ambiente selvagem por G. duodenalis, possivelmente devido à atividade humana.

Comunidades de aves de bosques y pastizales en los afloramientos rocosos aislados del Paraje Tres Cerros, Corrientes, Argentina / Bird communities of forests and grasslands on isolated rocky outcrops in Paraje Tres Cerros, Corrientes, Argentina

ResumenLos afloramientos rocosos aislados se describen como paisajes destacados en biodiversidad debido a la gran variedad de microhabitats, presencia de taxones restringidos y al alto recambio de especies con la matriz circundante. Particularmente los afloramientos rocosos aislados del Paraje Tres Cerros (ARPTC), Corrientes, Argentina, representan un paisaje único en la región, biológicamente fueron poco explorados. Se estudió la comunidad de aves de bosques y pastizales de los ARPTC mediante 136 listas de Mackinnon de diez especies durante la temporada reproductiva y no reproductiva. Se evaluó la diversidad, riqueza estimada y completitud de inventarios, abundancia de gremios tróficos y fenología de las especies. Se comparó estos atributos entre los bosques y pastizales. Se registraron 107 especies donde el bosque es 1.3 veces más diverso que el pastizal. La completitud de inventarios varió de 83 a 90 % en el pastizal y de 88 a 99 % en el bosque. Los hábitats se complementaron en un 62 % indicando una elevada ocurrencia de especies exclusivas. Las aves insectívoras fueron abundantes en ambos ambientes, mientras que las frugívoras en bosques y las granívoras en pastizales. Ambos hábitats son significativamente más ricos en especies en la estación reproductiva por la llegada de los migrantes estivales. Los resultados concuerdan con los patrones generales conocidos para las comunidades de aves y con otros específicos para las comunidades de aves de afloramientos rocosos. El presente estudio resalta la importancia de los afloramientos rocosos aislados de Paraje Tres Cerros para la protección de la biodiversidad de aves a nivel local y regional y representa una herramienta de manejo para la conservación de estos ecosistemas.

AbstractIsolated rocky outcrops can act as patch habitats that host great biodiversity through the diversity of microhabitats, presence of restricted taxa and the high turnover of species in the patch matrix. The isolated rocky outcrops of Paraje Tres Cerros (ARPTC), Corrientes, Argentina, are a unique landscape in the region and biologically little explored. We conducted a study to describe for the first time the bird community of the forest and grassland of the ARPTC, using 136 lists following the ten species Mackinnon method from the breeding and non-breeding seasons. We evaluated the diversity, trophic guilds and phenology of the species, and compared attributes of grassland and forest communities. The total species richness was 107, with the forest being 1.3 times more diverse than the grassland. Completeness of inventories ranged from 83-90 % in the grassland and 88 to 99 % in the forest. The habitat complementarity was 62 %, indicating the presence of several species exclusive of forest and grassland habitats. The trophic structure of communities showed a good representation of insectivorous birds in both habitats. Frugivorous birds were more frequent in the forest and granivorous birds were more frequent in the grasslands. Due to the arrival of migrant species, both habitats had significantly higher richness in the breeding season than in the non-breeding season. Our results showed similar general aspects and patterns for bird communities and with specific studies for bird communities of rocky outcrops. The present study highlights the importance of the isolated rocky outcrops of Paraje Tres Cerros for the protection of local and regional bird biodiversity and represents a benchmark for the management and the protection of these ecosystems.

The influence of habitat structure on fish assemblages in Amazonian streams of Machado river basin / Influencia de la estructura del hábitat en el ensamble de comunidades de peces en ríos de la cuenca amazónica Machado

Abstract:Igarapés are Amazonian streams that are extremely susceptible to environmental changes. Due to the rapidly occurring riparian land use changes, and the several impacts these may have on fish assemblages, it is highly valuable to describe and understand the current relationships between these assemblages and the local environmental conditions, especially in barely know areas. In this research, we studied the taxonomic composition and fish assemblage attributes variation in three streams with different riparian conservation conditions: forest, intermediate and pasture. Samplings were performed every two months from October 2011 to September 2012, in three 1st order streams in the Machado River Basin, Rondônia. Fish were collected using trawls (seine net with a mesh size of 2 mm) and dip nets (2 mm mesh) along the entire stretch; the obtained samples were preserved and identified per site type. A total of 2 141 fish specimens belonging to 59 species, 17 families and five orders were recorded. Unlike the intermediate and pasture streams, the forest stream showed a high richness and low abundance. The forested stream exhibited the highest diversity and evenness value, and had low dominance, unlike the other streams. The variance partitioning and partial Redundancy Analysis (pRDA) indicated that assemblage composition was significantly explained by the environmental variables such as: depth, water velocity, pteridophytes and grasses, but not by spatial predictors. The non-metric multidimensional scaling (NMDS) analysis showed that intermediate and pasture streams separated from the forested stream. We concluded that both, the stream environmental variables and fish assemblage attributes were influenced by the different conservation status and land cover. Given the influence of regional processes, which have a pervasive role in local fish assemblages, land use at the watershed scale is important, especially to explain the higher richness and diversity found in forested streams. Rev. Biol. Trop. 65 (1): 103-115. Epub 2017 March 01.

ResumenIgarapés son ríos amazónicos extremadamente susceptibles a los impactos ambientales. Debido al impacto de los cambios en el uso de las zonas riparias en los ensambles de peces, es importante describir y entender las relaciones entre los ensambles de peces y los factores ambientales, especialmente en áreas poco conocidas. Se estudió la composición taxonómica y los atributos del ensamble de peces en ríos bajo diferentes condiciones de conservación de la zona riparia: bosque, zona intermedia y pastos. Los muestreos se realizaron cada dos meses entre Octubre 2011 y Septiembre 2012, en tres ríos de primer orden en la cuenca del río Machado, Rondonia. Los peces fueron recolectados con redes de cerco y de profundidad (2 mm) a lo largo de todo el tramo. Se registró un total de 2 141 ejemplares pertenecientes a 59 especies, 17 familias y 5 órdenes. A diferencia de la zona intermedia y pasto, el bosque mostró una alta riqueza y baja abundancia. El área boscosa exhibió el valor más alto de diversidad y uniformidad, y baja dominancia, a diferencia de los otros sitios. La varianza particionada y el análisis de redundancia parcial (pRDA) indicaron que la composición del ensamble fue significativamente explicado por las variables ambientales como: profundidad, velocidad del agua, pteridofitas y pastos, pero no por predictores espaciales. El análisis de escalamiento multidimensional no métrico (EMNM) mostró que los ríos de sitios intermedios y pastos estaban separados de los ríos del bosque. Llegamos a la conclusión de que las variables ambientales de los ríos y los atributos del ensamble de peces se ven influenciados por los diferentes niveles de conservación y cobertura del suelo. En vista de la influencia de los procesos regionales en el ensamble de peces locales, el uso del suelo a escala de cuenca es importante, especialmente para explicar la alta riqueza y diversidad que se encuentra en el los ríos del área boscosa.

The protected areas system in Brazil as a baseline condition for wetlands management and fish conservancy: the example of the Pantanal National Park

Considering the need for the Brazilian government to develop tools for environmental monitoring for biodiversity conservancy purposes in the national protected areas system, this paper focuses on determining reference site metrics (or baselines) for adapting the Index of Biotic Integrity (IBI) based on the fish assemblages in the Pantanal National Park (PNP). The habitats in the PNP were grouped into four categories: main rivers, corixos (channels connecting the floodplain), permanent bays, and temporary bays. Fish samplings were performed at 12 points during the dry season (Oct-Nov 2010 and 2011). 146 fish species were identified from the total 18,954 individuals collected with standardized fishing gear. There was no association between the structure of the fish assemblage and categories, suggesting a theory on homogeneity of habitats. The final IBIPNP consists of nine metrics, most of them were framed in excellent class, some in fair, and none in poor. There was no significant difference in IBIPNP scores between the two sampled years. This approach provides a direct application for wetland management purposes.(AU)

É iminente que o Brasil desenvolva ferramentas para monitorar o sistema de áreas protegidas do país, formado especialmente pelas Unidades de Conservação e tendo como foco a proteção efetiva da biodiversidade. Nesse contexto, esse trabalho discute métricas de referência (ou linhas de base) para compor um Índice de Integridade Biótica (IIB) baseado nas comunidades de peixes, tendo como área de estudo o Parque Nacional do Pantanal Matogrossense. Os hábitats encontrados no Parque foram agrupados em quatro estratos ambientais: rios, corixos (cursos d´água que se conectam à planície de inundação) e baías permanentes e temporárias. As coletas de peixes foram realizadas em 12 pontos amostrais durante o período seco (out/nov de 2010 e 2011). Foram identificadas 146 espécies de peixes, totalizando 18.954 exemplares coletados em amostragens padronizadas. Não houve associação entre a estrutura da comunidade e os estratos ambientais, sugerindo homogeneidade de hábitats. O IIB final foi composto por nove métricas, a maior parte alocada na classe excelente de integridade biótica, poucas na classe regular e nenhuma na classe pobre. Não houve diferença significativa no IIB entre os dois anos consecutivos. Esses resultados oferecem subsídios técnicos para a tomada de decisão sobre a gestão das áreas alagáveis no Pantanal brasileiro.(AU)

Influence of environmental variables on stream fish fauna at multiple spatial scales

Effects of environmental variables at different spatial scales on freshwater fish assemblages are relatively unexplored in Neotropical ecosystems. However, those influences are important for developing management strategies to conserve fish diversity and water resources. We evaluated the influences of site- (in-stream) and catchment-scale (land use and cover) environmental variables on the abundance and occurrence of fish species in streams of the Upper Araguari River basin through use of variance partitioning with partial CCA. We sampled 38 1st to 3rd order stream sites in September 2009. We quantified site variables to calculate 11 physical habitat metrics and mapped catchment land use/cover. Site and catchment variables explained > 50% of the total variation in fish species. Site variables (fish abundance: 25.31%; occurrence: 24.51%) explained slightly more variation in fish species than catchment land use/cover (abundance: 22.69%; occurrence: 18.90%), indicating that factors at both scales are important. Because anthropogenic pressures at site and catchment scales both affect stream fish in the Upper Araguari River basin, both must be considered jointly to apply conservation strategies in an efficient manner.(AU)

Os efeitos das variáveis ambientais em diferentes escalas espaciais sobre as assembleias de peixes de água doce ainda é um tema pouco explorado na região Neotropical. Entretanto é um assunto de extrema relevância, pois gera subsídios para definições de estratégias de manejo e conservação de ictiofauna e dos recursos hídricos. Nós avaliamos a influência de variáveis ambientais em escalas local (dentro do rio) e da paisagem (uso e cobertura do solo) na abundância e ocorrência das espécies de peixes de riachos da bacia do alto rio Araguari através da partição da variância usando CCA parcial. Um total de 38 riachos de até 3ª ordem foi amostrado em setembro de 2009. Nós quantificamos variáveis locais para calcular 11 métricas de hábitats físicos e mapeamos o uso e cobertura do solo. O conjunto de dados (variáveis locais e da paisagem) explicou mais de 50% da variação total nas espécies de peixes. Variáveis em escala local (abundância: 25,31%; ocorrência: 24,51%) explicaram levemente uma maior variação nas assembleias de peixes do que o uso e cobertura do solo (abundância: 22,69%; ocorrência: 18,90%), indicando que os fatores em ambas as escalas de estudo são importantes. Uma vez que a influência antrópica em diferentes escalas afeta as espécies de peixes em riachos da bacia do alto rio Araguari, ambas devem ser consideradas juntamente para a adoção de estratégias de conservação de uma forma racional.(AU)