Abstract
A new species, Sellaphora balashovae sp. nov., from Lake Frolikha is described based on light (LM) and scanning electron microscopy (SEM). The systematic position of this new species is determined based on molecular data. This species is placed in the genus Sellaphora based on chloroplast morphology, areolae covered by external hymenes, and uniseriate striae that are typical for the genus. Molecular data support this taxonomic assignment, and the new species is part of a monophyletic group with some other members of the genus Sellaphora. The new species is distinguishable from other Sellaphora species by its small size, valve shape, striae and areolae densities, striae orientation and distinctly large areolae bordering the sternum.