A new small-celled naviculoid diatom species, Mayamaea pannonica sp. nov. (Bacillariophyceae) from soda pans in Serbia

ABSTRACT Combining morphological and molecular approaches, a new diatom species is described in the genus Mayamaea from a Special Nature Reserve, Okanj bara in Serbia, an alkaline and subsaline soda pan with pronounced seasonal drying. Mayamaea pannonica sp. nov. possesses typical characteristics of the genus Mayamaea, such as uniseriate striae and hymenes that cover the areolae from the outside. It can easily be distinguished from similar species by the valve outline and shape of the central area. Although presently no culture of the species is available, we identified in an amplicon data set from the same sample a partial 18S rRNA gene sequence that is thought to represent the new species, with high probability. A comparison of our sequence to those present in the Diat.barcode and NCBI databases showed that the sequence is closely related to, but significantly different from, that of Mayamaea terrestris. Natural saline habitats in Serbia and neighbouring countries are under anthropogenic threat and climate change, so knowing which species live here is the first step in preserving these unique habitats.