Pliocaenicus bolshetokoensis–a new species from Lake Bolshoe Toko (Yakutia, Eastern Siberia, Russia)

Abstract

© 2018, © 2018 The International Society for Diatom Research. A new species from the diatom genus Pliocaenicus Round & Håkansson is described from Yakutia (Eastern Siberia, Russia) as Pliocaenicus bolshetokoensis sp. nov., on the basis of light and scanning electron microscopy. The new species is morphologically similar to other members of the genus but differs from the closely related species, Pliocaenicus costatus (Loginova, Lupikina & Khursevich) Flower, Ozornina & Kuzmina and Pliocaenicus seczkinae Stachura-Suchoples, Genkal & Khursevich, mainly by the position of the central fultoportulae and the valve face relief. Variability of quantitative features such as valve diameter, number of striae and areolae in 10 µm, and number of central fultoportulae are similar to data known from other centric genera. The most variable quantitative character of P. bolshetokoensis sp. nov. is valve diameter; the numbers of areolae and striae in 10 µm were less variable.