Distribution of invasive species Actinocyclus normanii (Hemidiscaceae, Bacillariophyta) in Serbia

Abstract

In Serbia Actinocyclus normanii was registered in several rivers and canals. In 1997, it was found as planktonic species in the Tisza River and in benthic samples (in mud) in the Veliki Bački Canal. In 2002, it was found as planktonic species in the Danube–Tisza–Danube Canal (Kajtasovo) and the Ponjavica River (Brestovac and Omoljica). Four years later, in 2006, the species was found in plankton, benthos and epiphytic samples in the Ponjavica River (Omoljica). A. normanii is a cosmopolite, alkalibiontic and halophytic species. It occurs in waters with moderate to high conductivity and it is indicator of eutrophied, polluted waters. Its spread could be explained by eutrophication of surface waters.