Morphology and phylogeny of Nitzschianandorii sp. nov. (Bacillariophyceae), a new small-celled lanceolate species from a post-mining reservoir

Abstract Post-mining reservoirs are distinguished by characteristic environmental conditions where specific diatom communities can be observed. Reservoirs created as a part of the reclamation plan after human mining activities are marked by unique chemical and physical water parameters. In the course of research on the diatoms from Bogdałów reservoir, we examined the taxonomic and morphological diversity of Nitzschia taxa from the section Lanceolatae occurring in a post-mining lignite reservoir. Our study describes a new species of Nitzschia from a post-mining reservoir, Nitzschianandorii Olszyński, Zakrzewski & Żelazna-Wieczorek, sp. nov. Morphometry and morphology analyses of new species were performed with light and scanning electron microscopy. Chloroplast morphology analysis was conducted with differential interference contrast microscopy and confocal laser scanning microscopy. Molecular data from SSU 18S, rbcL and psbC sequences were obtained from cultures of this taxon. Differential diagnosis of Nitzschianandorii Olszyński, Zakrzewski & Żelazna-Wieczorek, sp. nov. with co-occurring taxa: N.lacuum and N.alpinobacillum was performed using morphological traits and nMDS analysis of the valves’ morphometry.