Hydromorphological discontinuities deeply modify the benthic multi-species assemblage diversity in a Mediterranean running river.

The aim of the study was to investigate the modifications of the macroinvertebrate multi-species assemblage in relation to hydromorphological discontinues, since macroinvertebrates are traditionally exploited in water quality assessment activities. Three sampling sites characterized by different hydrological characteristics were selected in five stations along the River Aniene in Central Italy. We evaluated the macroinvertebrate structure, traits, biotic and diversity indices in relation to the erosive power. Among macroinvertebrate taxa, Elminthidae and Chironomidae families showed a particular occurrence pattern associated with the site at the base of vertical drop, characterized by the stronger hydrodynamic. However, the water quality status was high, not showing differences between the three sites. Our finding has a novelty value as similar studies on the investigation of the hydromorphological discontinuities on macroinvertebrate structure and ecological traits are very scarce in the literature. [ABSTRACT FROM AUTHOR]