Aquatic macroinvertebrate assemblages of mountainous rivers in the Sutjeska National Park (Southeastern Bosnia and Herzegovina)

Abstract

The Sutjeska NP is the oldest national park in Bosnia and Herzegovina (BiH). Apart from caddisflies, aquatic macroinvertebrates of this region are scarcely explored. This study, performed in summer of 2015, was carried out to provide an overview of aquatic macroinvertebrate diversity and ecology. Macroinvertebrate assemblages of three mountainous rivers, the Hrčavka, the Jabušnica and the Sutjeska, were analyzed. Samples from eight localities were taken using standard FBA benthological net (multihabitat sampling procedure). During the investigation a total of 103 taxa from 16 macroinvertebrate groups were recorded. Insects belonging to orders Ephemeroptera, Plecoptera, Trichoptera and Diptera were the most diverse and abundant. Among them, mayflies Baetis vernus Curtis, 1834, Baetis rhodani Pictet, 1843, Rhithrogena semicolorata gr. Curtis, 1834, stonefly Protonemura montana Kimmins, 1941, and caddisfly Sericostoma personatum Kirby & Spence, 1826 were omnipresent. The study site Hrčavka 3, situated at the end of the Hrčavka Gorge, near the waterfall, was site with the highest taxa richness (50 identified taxa). This site is characterized by the significant habitat heterogeneity, which contributes to the high macroinvertebrate diversity. A few taxa considered rare for this region, including the mayfly Epeorus yugoslavicus Samal, 1935, and the beetle Riolus subviolaceus Müller, 1817 were found. The finding of caddisfly genus Drusus is significant since this may indicate possible presence of stenoendemites. This genus has island distribution and is known for its stenoendemites. In the region several endemic species were previously recorded.