New records of Navicula sensu stricto from Serbia with taxonomic notes and autecological characterization of Navicula splendicula and N. moskalii

A total of 15 Navicula taxa were recorded in epilithic communities occurring in seven rivers of Serbia, all of which are new to the diatom flora of Serbia. The most interesting of them are N. splendicula and N. moskalii. When observing N. splendicula specimens under SEM, we noticed a characteristic silicate tongue in the center of raphe ends, which had not been previously reported in the available literature. The insufficiently researched distribution of N. moskalii and scarce autecological information on the taxon prompted us to provide new details about the species in this study. These findings clearly indicate the need for further comprehensive research that would provide new information on rare taxa