Pantocsekiella minuscula (Bacillariophyta), a new diatom species to Russia

Abstract

Several small-sized centric diatom Pantocsekiella species were identified during a study of phytoplankton in the Krasnoyarsk Reservoir (Krasnoyarsk Territory, Russia) with the use of scanning electron microscopy. One of them, Pantocsekiella minuscula, is new for Russia. This species was previously known only from Europe (North Macedonia) and North America (USA, Canada). Comparison of such features as the diameter of the valve and its central area and the density of marginal fultoportulae is revealed differences from the original description of this species. Variability in the presence/absence and location of granules on the valve face was also shown, all of which enabled us to amend the species description. The new data on the occurrence of P. minuscula allowed us to expand the species distribution.