Structure and Spatial Distribution of the Chironomidae Community in Mesohabitats in a First Order Stream at the Poço D'Anta Municipal Biological Reserve in Brazil

Abstract

The Chironomidae occupy different habitats along the lotic system with their distribution determined by different factors such as the substrate characteristics and water speed. The input of vegetable material from the riparian forest allows a higher habitat diversity and food to the benthic fauna. The main aim of this paper is to verify the structure and spatial distribution of the Chironomidae fauna in different mesohabitats in a first order stream located at a Biological Reserve in the southeast of Brazil. In the months of July, August, and September 2007, and in January, February, and March 2008, samples were collected with a hand net (250 µm) in the following mesohabitats: litter from riffles, litter from pools, and sediment from pools. The community structure of each mesohabitat was analyzed through the abundance of organisms, taxa richness, Pielou's evenness, Shannon's diversity, and taxa dominance. Similarity among the mesohabitats was obtained by Cluster analysis, and Chironomidae larvae distribution through the Correspondence analysis. Indicator species analysis was used to identify possible taxa preference for a determined mesohabitat. The analyzed mesohabitats showed high species richness and diversity favored by the large environmental heterogeneity. Some taxa were indicators of the type of mesohabitat. The substrate was the main factor that determined taxa distribution in relation to water flow differences (riffle and pool). Stream characteristics such as low water speed and the presence of natural mechanisms of retention may have provided a higher faunistic similarity between the areas with different flows. The results showed that the physical characteristics of each environment presented a close relationship with the structure and spatial distribution of the Chironomidae fauna in lotic systems.

Occurrence of phoresy between Ancistrus multispinis (Actinopterygii: Siluriformes) and Ichthyocladius sp. (Diptera: Chironomidae) in Atlantic forest streams, Southeastern Brazil

“…Riparian degradation, which increases sedimentation and warming of the water, also contribute to stream degradation (Osborne andKovacic 1993, Casatti et al 2006). These changes have deleterious effects on the structure of the Chironomidae community, influencing composition and density (Pinder 1986, Rossaro 1991, Schmid 1992, Sanseverino and Nessimian 1998, Rosin et al 2009, Rosa et al 2011.…”

Inventory and distribution of Oligochaeta (Annelida, Clitellata) in first-order streams in preserved areas of the state of Minas Gerais, Brazil

“…In the state of Minas Gerais, studies in freshwater ecosystems have been carried out regarding various groups composing the community of benthic macroinvertebrates in preserved areas, such as the works of Callisto et al (2001), Goulart & Callisto (2005), Tupinambás et al (2007) and Rosa et al (2011). Nevertheless, none until now have focused on the Oligochaeta.…”

Impactos do uso do solo nos recursos hídricos da bacia de contribuição do Lago dos Manacás, Minas Gerais, Brasil

“…Estudo realizado em córrego de primeira ordem numa reserva biológica no mesmo município, Rosa et al, (2011) …”