Chironomidae (Insecta, Diptera) from Alto Paranapanema Basin, southeastern Brazil

Abstract

The usual conclusions in such studies focus on the negative aspect of the conversion of riparian forest to agricultural land (Cetra and Petrere 2007;Galbraith et al. 2008). Their presence is important for the maintenance of temperature equilibrium, as continous food supply for aquatic animals, as source of organic material and stabilization of stream banks (Marinho Filho and Reis 1989;Rodrigues 1992;Aguiar et al. 2002).Because of their widespread distribution and the sensitiveness to pollution observed for some species, chironomids are used worldwide as biological indicators of environmental quality (Bacey and Spurlock 2007;Chessman et al. 2007; Smith et al. 2007). Several projects around the world demonstrate their application as bioindicators (WRC 2001; MDFRC 2007).In Brazil, several studies have been conducted in order to analyse the influence of the surrounding land-use on the aquatic fauna (Sonoda 2005;Corbi and Trivinho-Strixino 2008). The interaction of terrestrial and aquatic systems is often analysed in small watersheds in an attempt to reduce the influence of extraneous environmental factors that, consequently, make it more difficult to detect the effects of differences in catchment landuse (Siqueira and Trivinho-Strixino 2005;Roque et al. 2008). Studies conducted on large Brazilian aquatic systems are rare in the scientific literature; as the velocity of river flow and sudden changes in the water level are some of the difficulties encountered.As stated by Vinson and Hawkins (2003), streams within similar biomes support similar number of taxa. This implies that the physical and biological environment of streams are a strong selective force on insect stream communities.The rivers studied here are similar with regard to land-use and cover, terrain slope, river channel morphology and climate. Our objective was to analyze if the Chironomidae communities from AbstractWe investigated the community of Chironomidae from three rivers belonging to the same river basin in Southern Brazil. Our objective was to analyze if the Chironomidae communities from rivers of the same basin were similar and relate this to land-use and water quality variables. Samples of insects were taken using artificial substrate baskets and left 44 days in the field for colonization during the dry season in 2002. Study reaches with the relevant land-use category present for at least 500 m along both river banks above and alongside the study reach were selected and land-use, terrain slope of the river basin and chemical and physical variables of the water were analysed. Faunal data were analyzed by number of individuals, richness of genera and community indices. Statistical analyses were performed in order to investigate the relationship between abiotic variables and the Chironomidae communities. Twenty-two genera were identified; Rheotanytarsus (Thienemann & Bause) was the most abundant in all assemblages. Some genera showed preferences in their distribution, and were observed in only one of the rivers. Land-use and slope of the terrain ...

Short comment on Chironomidae (Insecta: Diptera) from Brazil’s Federal District

“…Rheotanytarsus was documented as one of the most abundant taxa in several Brazilian studies (Sonoda et al 2009b, Sonoda et al 2010, Floss et al 2012; this numerical dominance is related to agricultural land use (Sonoda et al 2009a, Sonoda et al 2018. Its abundance is also documented in other neotropical countries, like Trinidad (Helson et al 2006).…”

“…The limited knowledge in chironomid biodiversity is not necessarily due to lack of research conducted within the Cerrado, but rather the extensive area that the biome occupies. Additionally, few focus exclusively on Chironomidae (Sonoda et al 2009a, Sonoda et al 2009b, Saito and Fonseca-Gessner 2014, Mazão et al 2016. When considering the Federal District region, we notice that most studies analyze the entire aquatic entomofauna and the influence of human activities on Figure 1.…”