Benthic macroinvertebrate community structure in a stream of the north-west region of Paraná State, Brazil

Abstract

<jats:p>This study aimed to survey the benthic macroinvertebrate fauna of a first order stream located in an agricultural area, and to assess the environmental factors involved in the spatial distribution of this community. Invertebrates were gathered in November 2007 at three sampling sites distributed along the Itiz Stream, located in Marialva municipality, Paraná State. At each site, we measured the physical and chemical variables of the water, and then took four samples, using Surber sampler. In order to evaluate the differences in density, richness, diversity and evenness, we employed an ANOVA and a DCA to summarize biotic data. The invertebrates were categorized into functional groups and the BMWP score was applied to calculate the biological integrity of the environment. The faunal composition was represented by 103 taxa distributed across five phyla, of which the highest occurrence was of arthropods, especially insects. Higher density values were observed for Chironomidae, Ephemeroptera, Coleoptera and Trichoptera. The richness, diversity and density, as well as the density of gathering-collectors, were higher in the intermediate course of the stream. The distribution pattern of the taxa was mainly influenced by lentic or lotic characteristics of the sampled sites and microhabitats, as evidenced by the DCA. The BMWP indices indicated that the three sampling sites presented scores of excellent and good water quality. In the Itiz Stream, the presence of preserved marginal vegetation and the distance from urban centers that generate pollution, combined with peculiarities of each sampling site, influenced the structure of the benthic community.</jats:p>

Food-resource partitioning among fish species from a first-order stream in northwestern Paraná, Brazil

“…iheringi, which capture benthic aquatic insects (Casatti, 2002;Abilhoa et al, 2008;Rezende et al, 2011). The high consumption of immature ephemeropterans, plecopterans and trichopterans was probably related to their high abundances in Itiz stream, as observed by Bagatini et al (2012) in samples of macroinvertebrates collected simultaneously with this study.…”

Diet and ecomorphological relationships of an endemic, species-poor fish assemblage in a stream in the Iguaçu National Park

“…This is verified by the presence of (i) a considerable amount of terrestrial insects (Hymenoptera and Coleoptera), seeds, and plants, which attests to the contribution of the riparian vegetation to the input of organic matter to the system (Uieda & Pinto, 2011;Casatti, 2010;Moraes et al, 2013); (ii) the presence of organisms such as Ephemeroptera, Trichoptera, Plecoptera and Decapoda (Aeglidae) that are considered to be bioindicators of environmental quality and the structural complexity of the river bed (Bispo et al, 2006;Bagatini et al, 2012;Silva et al, 2012). In these context, the results about fish's diet, indicate that the Jumelo stream may used as a possible reference environment (sensu Ferreira & Casatti, 2006) for comparisons of trophic ecology between fish communities in impacted versus nonimpacted environments.…”

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“…According to the results of biotic rates (BMWP-CETEC and IBE-IOC), Stations A and C present better environmental integrity, Stations B and E are the most impacted and Station D presents intermediate condition. The BMWP index is one of the metrics most used in biomonitoring studies in neotropical regions (Baptista et al, 2007;Bagatini et al, 2012). Suriano et al (2011) developed a new multimetric index for southeastern Brazilian ecosystems, using as a basis the BMWP-CETEC index, and demonstrated the broad sensitivity of this metric investigating large regional scale.…”