Pantocsekiella, a new centric diatom genus based on morphological and genetic studies

Abstract

The paper is dedicated for 100th death anniversary of the famous Hungarian diatomologist Jozsef Pantocsek (1846-1916). Previous morphological studies showed that the description of the Cyclotella genus was too general and according to new morphological criteria new genera were established based on both recent and fossil taxa (e.g. Discostella, Handmannia, Puncticulata, Tertiarius). Furthermore, previous molecular biological investigations proved that the Cyclotella genus was not monophyletic. Integrating the above mentioned knowledge the former Cyclotella genus has been split into 4 genera (Cyclotella s.s., Discostella, Tertiarius and Lindavia). Based on the position of rimoportula Lindavia genus was formed for involving the species of both the Cyclotella ocellata and C. bodanica lineages. Our morphological and molecular (genetic distance and phylogenetic analyses of rbcL and 18S rDNA sequences) investigations suggested that Lindavia/Cyclotella ocellata group could be raised from the Lindavia as a separate genus. Its distinctive morphological features are the followings: striae unequal in length, central area without areolae. We describe the new genus Pantocsekiella gen. nov. and we transferred several Lindavia taxa into it. We also provide an amended diagnosis for the genus Lindavia.