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

摘要

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