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Abstract The decomposition of leaf litter of Tessaria integrifolia and its colonization by invertebrates were studied in the Tiradero Viejo River Leaves were collected at abscission and 6g dry weight and were placed in nylon bags with 5... more
Abstract The decomposition of leaf litter of Tessaria integrifolia and its colonization by invertebrates were studied in the Tiradero Viejo River Leaves were collected at abscission and 6g dry weight and were placed in nylon bags with 5 mm mesh net. Samplings were ...
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This study analyzed the effects of the herbicide Paraquat (1-1'-dimethyl-4-4'-bipiridylium dichloride ion) on zooplankton and zoobenthic assemblages and their capacity to recover. The herbicide caused a decrease in the abundance... more
This study analyzed the effects of the herbicide Paraquat (1-1'-dimethyl-4-4'-bipiridylium dichloride ion) on zooplankton and zoobenthic assemblages and their capacity to recover. The herbicide caused a decrease in the abundance and biomass of larger-sized individuals (cladocerans, adult copepods and molluscs). The zoobenthos assemblage required a longer time to recover its structure than the zooplankton one. The number of zooplankters species was less affected than their density, in contrast to the benthos. The benthos and zooplankton species associations diminished considerably and the composition of the survivors determined the outcome of secondary succession.
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To explore temporal variation in trophic relationships of benthic invertebrates in the Middle Paraná River floodplain, we performed stable isotopes analysis (SIA) in two lakes with contrasting morphologies during both dry and flooding... more
To explore temporal variation in trophic relationships of benthic invertebrates in the Middle Paraná River floodplain, we performed stable isotopes analysis (SIA) in two lakes with contrasting morphologies during both dry and flooding periods. Lake 1 is permanently connected, large and deep with a narrow aquatic–terrestrial transition zone (ATTZ), and Lake 2 is temporarily connected, small and shallow with a wide ATTZ. The source contribution analysis showed that macrophytes and sediment particulate organic matter are important basal resources. We found sharp temporal variations with regard to gatherer–collectors in Lake 2, being sediment particulate organic matter the most important source during dry period. However, during flooding, macrophytes and epiphyton increased their importance. Our results reveal temporal variations in trophic interactions, suggesting that hydrologic and morphologic characteristics of water bodies can be important factors determining food web structure. Besides, we provide evidence from floodplain lakes of the Middle Paraná River, which contradicts the general idea that algae is the main carbon source in floodplain rivers.
Research Interests: Earth Sciences, Environmental Science, Wetlands, Stable Isotopes, Ecology, and 11 moreBiological Sciences, Environmental Sciences, Food web, Wetland, Neotropics, Trophic Level, Floodplain, Trophic Relationships, Benthic invertebrates, Enseñanza - Aprendizaje Ciencias Naturales Y Exactas, and Macrophyte
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The present study was aimed at analyzing chromium concentrations in water column and bottom sediments in the main channel of Northern Salado River (tributary of Middle Parana River) and its floodplain. The main changes caused by human... more
The present study was aimed at analyzing chromium concentrations in water column and bottom sediments in the main channel of Northern Salado River (tributary of Middle Parana River) and its floodplain. The main changes caused by human activities and hydrological disturbances on benthic invertebrate structure were also analyzed. Sediment concentrations of the reference area varied between 44.2 and 97.1 microg Crg(-1) (dw), and in the impacted zone, between 85.5 and 209 microg Cr g(-1) (dw) reaching the highest values in the wetland floodplain. Alfa, beta and gamma diversities in the reference section have been 33, 9 and 66 species, and in the disturbed section, they have been 37, 8.33 and 74 species, respectively The species dominant in the disturbed habitats were characterized by a small body size and short life cycles, as the species of olig chaetes Naidinae. The extreme flooding produced a rejuvenation of the area with the consequent physical re-structuration produced by flooding, showing: a marked decrease in chromium levels in sediments and in organic matter content, which allowed the colonization of insects (Ephemeroptera and Trichoptera).
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Research Interests: Evolutionary Biology, Genetics, Zoology, Molecular Systematics, Molecular Evolution, and 15 moreBiology, Medicine, Bayesian Inference, Phylogeny, Mitochondrial DNA, Close relationships, Animals, Molecular Phylogenetics and Evolution, Oligochaeta, ribosomal RNA, Ciencias Biológicas, Cell nucleus, Ribosomal DNA, Clitellata, and Taxon
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ABSTRACT Obtaining unbiased samples of aquatic and terrestrial invertebrates from wetlands provides unique challenges due to the varied life history strategies of invertebrates as well as the heterogeneity present within a wetland. Many... more
ABSTRACT Obtaining unbiased samples of aquatic and terrestrial invertebrates from wetlands provides unique challenges due to the varied life history strategies of invertebrates as well as the heterogeneity present within a wetland. Many sampling devices are useful in more than one sampling environment within a wetland but the effectiveness of most methods varies among and within wetlands as well as between users. In this chapter, we emphasize field collecting techniques and address laboratory sorting methods. When possible, the advantages and disadvantages of each method are listed and suggestions are provided to reduce bias and unwanted variability in sample collection. Sampling devices for benthic (grabs, single and multiple cores, nets, and artificial sub-strate), water-column (open cylinder, emergence trap, activity trap, sweep net), epiphytic (box samplers, quadrat samplers), flying terrestrial (aerial net, flight intercept trap, light trap, malaise trap), and non-flying terrestrial (sweep net, aspirator, vacuum sampler, Berlese-Tullgren funnel, mist net) invertebrates are presented and discussed.
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Research Interests: Environmental Engineering, Geography, Environmental Science, Water Engineering, Ecology, and 14 moreCommunity, Biodiversity, River, Wetland, Habitat, Floodplain, Species Diversity, Benthos, Invertebrate, Benthic Invertebrate Ecology, Tributary, ENVIRONMENTAL SCIENCE AND MANAGEMENT, Functional Units, and Flood plain
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... 11-0 12-0 13-0 14-0 15-0 16-Sesshi 22-+ 22-PisiEium sp. 24-04 25-Camasurus 20-+ 31-+ II through layers of sandstones of the Ituzaing6 for-mation (Gentile & Rimoldi, 1979). Materials and methods The samples analysed were... more
... 11-0 12-0 13-0 14-0 15-0 16-Sesshi 22-+ 22-PisiEium sp. 24-04 25-Camasurus 20-+ 31-+ II through layers of sandstones of the Ituzaing6 for-mation (Gentile & Rimoldi, 1979). Materials and methods The samples analysed were 414, corresponding to the period 1978-88 . ...
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Simple and multiple correlations among physical and chemical parameters and densities of the dominant Oligochaete species were calculated for various channels of the middle Paraná valley and its tributaries. Paranadrilus descolei... more
Simple and multiple correlations among physical and chemical parameters and densities of the dominant Oligochaete species were calculated for various channels of the middle Paraná valley and its tributaries. Paranadrilus descolei Gavrilov, 1955, was observed in rivers with average depth and current velocity, mud-clay sediments, and low conductivity. Tubifex tubifex f. blanchardi Vejd., 1891, was found in channels of low
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The metacommunity theory is a framework that explains the interdependence of local factors and regional processes as community drivers. In rivers, it has been hypothesized that the metacommunity structure and the relative importance of... more
The metacommunity theory is a framework that explains the interdependence of local factors and regional processes as community drivers. In rivers, it has been hypothesized that the metacommunity structure and the relative importance of dispersal and local environmental conditions may vary from headwaters toward lowlands. The aims of this study were (1) to analyze the benthic metacommunity structure along the longitudinal dimension of the Paraguay‐Paraná system, and (2) to assess the relative importance of dispersal (spatial structure) and niche‐based processes as drivers of these structures. We used data of oligochaetes assemblages in the studied system and analyzed the Elements of Metacommunity Structure in different river sections. Moreover, we performed a variance partitioning analysis to determine the relative importance of spatial and environmental variables. In the upper section, we found a gradient structure (Gleasonian) and in the lower section we found random and quasi‐Clementsian structures. Similarly, environmental variables were the main structuring factor in the upper section while spatial variables were more important in the delta. The present study provides evidence that metacommunity structure and the underlying mechanisms that shape it, change along the longitudinal dimension of a large South American River. However, we emphasize the necessity of further studies assessing other taxonomic groups and other large South American Rivers.
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Aim: Our aim in this study was evaluate the effects of flow regulation for irrigation on the macroinvertebrate assemblages in a semiarid river. Methods We sampled two reaches in Dulce River; one placed upstream a weir that diverts flow... more
Aim: Our aim in this study was evaluate the effects of flow regulation for irrigation on the macroinvertebrate assemblages in a semiarid river. Methods We sampled two reaches in Dulce River; one placed upstream a weir that diverts flow into a network of irrigation channels and the other downstream that weir, in the assessment of the fluvial discontinuity. We assess the differences among reaches and sites, environmental variables, invertebrate density, richness and Shannon-Wiener index applying non-parametric analyses of variance Kruskal Wallis. The similarity percentage analysis (SIMPER) was used to identify which species contributed to the dissimilarities on macroinvertebrate assemblage structure. Canonical Correspondence Analysis (CCA) was performed with the total set of samples to explore macroinvertebrate distribution in reaches and associations of the assemblages with habitat variables. Results The density, richness and Shannon index values did not show differences between the ...
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Food chain length (FCL) is a key integrative variable describing ecosystem functioning. The aim of the present study was to test the hypothesis that the relative importance of planktonic and benthic energy pathways is a major factor... more
Food chain length (FCL) is a key integrative variable describing ecosystem functioning. The aim of the present study was to test the hypothesis that the relative importance of planktonic and benthic energy pathways is a major factor affecting FCL in the Middle Paraná River. Samples were obtained from in eight waterbodies, measuring chlorophyll-a concentrations and the abundance of benthic invertebrates and the trophic position of top predators by stable isotope analysis. There was no evidence that resource availability, disturbances or ecosystem size limited FCL. Similarly, the body size and trophic position of predators were not correlated. However, the relative abundance of planktonic and benthic resources was correlated with FCL. In addition, stable isotopes analysis showed that the benthic reliance of top predators is correlated with their trophic position. The results of the present study indicate that because the major benthic primary consumer is a large fish (Prochilodus line...
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QuestionsUnderstanding the processes that determine the variation in community composition (β‐diversity) is a major challenge in ecology, evolution, and conservation. Here we assess the importance of abiotic variables associated with... more
QuestionsUnderstanding the processes that determine the variation in community composition (β‐diversity) is a major challenge in ecology, evolution, and conservation. Here we assess the importance of abiotic variables associated with local environmental features, hydrogeomorphology, and space to explain β‐diversity patterns in macrophytes by addressing the following questions: (1) Which are the sets of environmental, hydrogeomorphological, and spatial variables that contribute significantly to the spatial variation of macrophytes? (2) Which are their relative contributions to explaining the total β‐diversity, nestedness and turnover of macrophyte assemblages?Study SiteMiddle Paraná River floodplain, Argentina.MethodsWe sampled 20 lakes at low and high water levels in the Middle Paraná River floodplain. To investigate the relationship of total β‐diversity, turnover and nestedness with explanatory variables, we used the constrained analysis of principal coordinates (CAP). We used vari...
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Urban aquatic ecosystems are important sources of fresh water for multiple uses, but often receive a point or diffuse anthropic contamination. Benthic and zooplankton invertebrates are sensitive to water quality, being good indicators of... more
Urban aquatic ecosystems are important sources of fresh water for multiple uses, but often receive a point or diffuse anthropic contamination. Benthic and zooplankton invertebrates are sensitive to water quality, being good indicators of ecosystem health. In this study, the composition and structure of benthic and zooplankton communities and environmental variables were analyzed seasonally in six urban wetlands of Santa Fe City (Argentina). We present the effect of water quality on both communities as bioindicators of ecological conditions, using different community attributes, functional feeding groups, and biotic indices. For the benthic community, the Macroinvertebrate Index for Pampean Rivers (IMRP) and the Benthic Community Index (BCI) were selected. For the zooplankton community, abundance of rotifers/abundance of total zooplankters, microcrustaceans/total zooplankters, cladocerans/total zooplankters, and macrozooplankton/microzooplankton ratios were applied. A functional feed...
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An updated taxonomic review of freshwater Annelida found in the Neotropical and Antarctic Regions is presented in this chapter. This chapter provides dichotomous identification keys to Polychaeta, Clitellata, and Aphanoneura. Also... more
An updated taxonomic review of freshwater Annelida found in the Neotropical and Antarctic Regions is presented in this chapter. This chapter provides dichotomous identification keys to Polychaeta, Clitellata, and Aphanoneura. Also included are current limits to identification of various annelids, a description of terms needed to identify taxa, and methods for preparing and identifying species. Additional information on annelids can be found in Volume I (“Ecology and General Biology”) of this book series (Thorp & Rogers, 2015, Elsevier).Peer reviewe
Fil: Marchese Garello, Mercedes Rosa. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Santa Fe. Instituto Nacional de Limnologia. Universidad Nacional del Litoral. Instituto Nacional de... more
Fil: Marchese Garello, Mercedes Rosa. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Santa Fe. Instituto Nacional de Limnologia. Universidad Nacional del Litoral. Instituto Nacional de Limnologia; Argentina