Riqueza de especies y similaridad de los invertebrados que viven en plantas flotantes de la planicie de inundación del río paraná (argentina)

summary an intensive survey was carried out in 5 sites of the paraná river floodplain with similar physical and chemical water condition, dominated by different macrophytes. to test the hypothesis that the invertebrate species richness is affected by the specific composition of the dominant macrophytes, the similarity of taxonomic groups among 7 species of free and rooted floating plants with different bioarchitecture was compared. the number of species within each trophic groups was used to elucidate the importance of the macrophytes as substrate. invertebrates were collected by enclosing 962cm2 of macrophyte stands with a 500μm mesh net. at the study area, 8 major groups of invertebrates were found encompassing 53 families and 152 species. the rank of species richness was eichhornia azurea >eichhornia crassipes >paspalum repens >pistia stratiotes >salvinia biloba >azolla caroliniana >lemna sp. the complete linkage showed a moderate and high level of distinctness between the invertebrates related to aquatic floating macrophytes in the study area. the relationship between the number of species of invertebrates and the plant biomass was tested. the results indicated that in the vegetated area there were a high number of species of collectors or predators