Vladinikolaevia, gen. nov. - a new enigmatic freshwater diatom genus (Cymbellaceae; Bacillariophyceae) from Mongolia

Abstract

: We studied a new freshwater cymbelloid diatom taxon collected from Mongolia with light and scanning electron microscopy. The monotypic genus Vladinikolaevia gen. nov. , based on V. mongolica sp. nov, is described. The new genus is characterized by a combination of morphological features found in two well–known genera such as Cymbella and Encyonema . The raphe system is morphologically–similar to Encyonema but the presence of apical pore fields is similar to the genus Cymbella as presently circumscribed. There are other very interesting peculiarities found in V. mongolica sp. nov. that show it to be a distinct taxon. We discuss the morphology of this new genus in the context of valve morphogenesis and presence of primary and secondary valves. The description of this new genus from Mongolia supports our contention that Asia is home to many endemics, interesting and not yet described cymbelloid taxa.