INVERTEBRATE FAUNA OF THE MIDDLE COURSE OF THE GRADAŠNICA RIVER, EASTERN SERBIA

The Gradašnica River originates on the Ozren Mountain, in the Landscape of exceptional features “Ozrenske meadows“ area. After approximately 6 kilometers it flows into the Sokobanjska Moravica as a left tributary. Along the stream, areas of fast and slow flow alternate. The invertebrate fauna is moderately rich, with the probable presence of another 10-20 species. Quantitatively, individuals from the genus Gammarus and the orders Ephemeroptera and Trichoptera dominate, with the subdominant species Gerris lacustris in calmer areas. A total of 14 taxa were recorded, from which some without possibilty of precise identification.