Nuisance algae Gonyostomum semen (Raphidophyta) in water bodies of protected natural areas in Middle Volga region (Russia)

Abstract

Abstract The distribution if nuisance raphidophyte Gonyostomum semen in water bodies of protected natural areas of the Middle Volga region is analyzed. The abundance of the species was determined quantitatively in eight lakes using the method of fixation with mercuric chloride. In four more lakes, it was found by qualitative inspection of live samples. It develops mainly in lakes with high water color, reaching the cell number of 7.5 106 cells L1, but also occurs in clear-water lakes in minor abundance (10-1600 cells L−1). It has been demonstrated that some ciliate species e.g. Frontonia leucas can consume G semen cells and therefore partially control its abundance. Taking into account the presented data, this species was recorded in the plankton of lakes in all regions of the forest part of the Middle Volga basin. Thus, these results significantly expand the geography of the planktonic habitats of G semen in the whole Volga region.