Fauna Asociada a las Raíces de Eichhornia Crassipes en una Laguna del Valle Aluvial del Río Paraná ("Los Matadores", Santa Fe, Argentina)

Abstract

Different groups of organisms found in the Eichhornia crassipes roots from Los Matadores lagoon have been studied. The detected groups were the following: Thecamoeba, Nematoda, Oligochaeta, Rotifera, Copepoda, Cladocera, Ostracoda, Amphipoda, Decapoda e Insecta. The faunal composition was heterogeneous in different places and times, both qualitatively and quantitatively. Their absolute densities were estimated as well as the biomass of the Insects and Amphipoda. The densities of the organisms related to the E. crassipes roots ranked from 115.460 to 8.830 ind./m super(2). The biomass ranked from 2.860 to 1 mg/m super(2). The Sorensen-Dice index was applied to the Cladocera, while the quantitative association was estimated applying the Steinhaus formula through the non-weighed pair groups method using arithmetic means