Aquatic Micro-Invertebrates Richness in Trails in The Region of Três Marias MG Brazil

Abstract

Zooplankton, zooperipheral and zoobenthic communities at different stages of conservation of six trail segments in the region of Três Marias MG Brazil, high-middle São Francisco river, were researched in April 2009 to characterize their aquatic micro-vertebrate richness. One hundred and twenty-two taxa were identified, with the highest richness for Protists, especially Difflugiidae and Nebelidae, followed by rotifers Lecanidae. The occurrence of most taxa was sporadic and by chance, of which the most constant were Centropyxis cassis, C. platystoma, Pseudonebela africana, Euglypha laevis, Arcella crenulata, A. hemisphaerica hemisphaerica, Euglypha denticulata and Trinema enchelys. Trail richness was significantly distinct for Protists, Filosea, Nebellidae, Lobosea and Euglyphidae. The São José trail (segment one) was the richest and had the lowest fauna affinity with the others. Differences in rotifers were not significant but the zooplankton community was the richest, followed by zooepiphyton and zoobenthon communities, albeit with no difference between the trails. Highest fauna similarity occurred between the Serena and Curral das Éguas trails with scantily impacted areas, and between the Buriti and São José trails heavily impacted by humans. Above associations were maintained among the communities, especially for the zooplankton, with slight changes for zoobenthon and different for zooepiphyton.