Ephemeroptera, Plecoptera e Trichoptera assemblages in Miranda River basin, Mato Grosso do Sul State, Brazil

Abstract

The knowledge on the Ephemeroptera, Plecoptera and Trichoptera (EPT) assemblages in running waters of Mato Grosso do Sul State is still deficient. As a contribution to improve this situation, this study presents an inventory of immature EPT assemblages in Miranda River basin. The samples were collected between January and September 2006 from 4th to 7th orders river reaches. A total of 3069 larvae were collected, belonging to 49 genera and 17 families. The caddisflies presented the greatest abundance while the mayflies presented the greatest richness. Of the larvae collected, 22 genera of Ephemeroptera and 20 of Trichoptera are new occurrences for the State. The high genera richness observed in this study, with sites subjected to moderate to high human impacts, as well as the high genera richness indicated by non-parametric estimators and by the genera accumulation curve, indicate that the EPT richness of Miranda River basin is high. This result seems to be related to the environmental heterogeneity of the basin catchment (Cerrado and Pantanal biomes; carbonate, sedimentary and basaltic rocks). Additionally, these results should incentive future ecological and environmental integrity studies in the region, which are urgent in a landscape under fast anthropogenic impacts.