MORPHOLOGY AND TAXONOMY OF THE RARE SPECIES NUPELA SILVAHERCYNIA (LANGE-BERTALOT) LANGE-BERTALOT (BACILLARIOPHYTA)

Abstract

This electron microscopy study was undertaken to investigate morphological features of the frustule of the diatom Nupella silvahercynia. Materials from Lake Pizanets (Republic of Karelia) and S.I. Genkal’s iconotheca of scanning electron microscopy images of valves collected from Karelian water bodies and watercourses were used. A comparative analysis of quantitative (valve length and width, number of striae and areolae in 10 µm) and qualitative (shape of valve, central and axial areas, arrangement of raphe and striae) features showed the similarity of this species with N. vitiosa, which made it possible to reduce N. silvahercynia to synonymy of the latter. The new data also allowed us to expand the diagnosis and range of N. vitiosa.