Zero Intercalary Plates in Parvodinium (Peridiniopsidaceae, Peridiniales) and Phylogenetics of P. elpatiewskyi, comb. nov.

Abstract

Parvodinium elpatiewskyi, comb. nov., is a common freshwater dinophyte without intercalary plates and with various spines on hypothecal sutures. However, the taxonomy of the species has had a complex history, and its systematic placement remained unclear. The conserved type of P. elpatiewskyi, comb. nov., illustrated here for the first time using electron microscopy, is an environmental sample. Based on the newly collected material from Berlin (Germany) we provide a morphological description using light and electron microscopy as well as new molecular rRNA sequence data to specify the phylogenetic position of P. elpatiewskyi, comb. nov. This species belongs to Peridiniopsidaceae, more precisely to Parvodinium, which usually possesses two intercalary plates. However, evolutionary inference indicates the loss of such plates in P. elpatiewskyi, comb. nov. Other traits that are of taxonomic importance and have not received enough attention in the past are the large Sd plate converging the second antapical plate and the presence of cellular hypocystal opening during replication. (C) 2019 Elsevier GmbH. All rights reserved.