Diversity of freshwater gastropods in the Danube wetland area Dubovački rit, (1082 - 1085 river km).

Abstract

Aim: This study provides data about the freshwater gastropods of the Danube wetland area Dubova ki Rit (1082 1085 river km), aiming to contribute to the knowledge of this taxa group, its assemblage composition and species abundances. Materials and Methods: The study of freshwater gastropods was performed in the Dubova ki Rit at the left bank of the Danube River. Sampling was performed in 2010, 201l and 2014, four times per year using benthological hand net and a Van Veen type of grab. The yotal number of taxa, species composition and abundance were calculated using the ASTERICS software package. Results: During the research a total of 12 species were recorded, all belonging to the Planorbidae family. The most abundant species were Segmentina nitida (M., 1774)- 16 specimens, Physella acuta (D., 1805) - 12 specimens, Hippeutis complanatus (, 1758) 11 specimens, Ferrissia fragilis (T., 1863) - 10 specimens and Anisus vortex (L., 1758) - 9 specimens. Other species were represented with less than 5 specimens (Gyraulus albus, G. erista, Bathyomphalus contortus, Planorbarius cormeus, Planorbis planorbis, Acroloxus lacustris and Lymnaea stagnalis). Two species (P. acuta and F. fragilis) are nonnative to the Danube River. At the site inavasive macrophyte Paspalum paspaloides (Michx.) forms underwater meadows. Conclusion: The majority of the observed species are phytophilowus taxa. Seasonal differences in macrophyte density and community composition additionally contribute to the habitat complexity. On this specific the habitat dominated by invasive P. paspaloides two alien species of snails were recorded.