Ostracoda (Crustacea) in lotic mountain-river habitats in Serbia

Abstract

Small crustaceans belonging to class Ostracoda are present in various aquatic habitats worldwide. Freshwater ostracods have calcified bivalved carapace, and they inhabit ponds and lakes mostly as nectobenthos and crawlers. In fast-flowing rivers and streams, their presence is limited to sheltered places with calmer water and groundwater habitats, such as interstitial waters connected to riverbeds. With the aim to explore their presence and ecology in highland rivers in the mountain region in Serbia, special attention was devoted to their separation from the samples collected in the study of benthic communities in mountain rivers during 2011 – 2012. Invertebrates are collected with Surber-net, taking three samples per locality. Basic physical and chemical parameters are measured on site, and water samples are also collected for further laboratory analyses. To relate occurrence of detected species with measured environmental parameters, Canonical Correspondence Analysis was performed with MVSP by Kovach Computing Services. Ostracods are found in samples from Radovanska, Crnica, Vrla and Mlava rivers, where 5 species belonging to 3 genera are identified. The most frequently sampled species were Candona candida and Psychrodromus olivaceus. Candona neglecta was found in two samples, while Psychrodromus fontilalis and Prionocypris zenkery were recorded only once on different sites. CCA revealed that the ostracod assemblages were mainly affected by measured conductivity. The new findings of named species present significant contribution to the knowledge on diversity of ostracod fauna in the central part of the Balkan Peninsula.