Revision of Monoraphid Diatom Genus Platessa with Description of Platesiberia gen. nov. from Ancient Lake Baikal

Abstract

A new monoraphid diatom genus, Platesiberia gen. nov., is described based on a detailed morphological investigation using light and scanning electron microscopy. The genus is based upon P. rhombicolanceolata Kulikovskiy & Lange-Bertalot and includes Platessa baicalensis Kulikovskiy & Lange-Bertalot, both species previously described from ancient Lake Baikal. Platesiberia gen. nov. is characterized by having biseriate striae on the raphe valves with uniseriate striae on the rapheless valves. Morphology of striae is helpful to distinguish the genus Platesiberia from Platessa and other monoraphid genera, and we provide a comparison of the new Baikalian genus with other freshwater monoraphid groups.

Molecular Investigation of the Achnanthidium minutissimum Complex (Bacillariophyceae) from the Transbaikal Region with the Description of Three New Species

“…The diverse and distinctive diatom flora of the lake has been a focus of many studies since the early 20th century [1]. The nonmonophyletic group of monoraphid diatoms has been studied quite extensively in Lake Baikal during the last two decades, with descriptions of many new species and several new genera, such as Trifonovia Kulikovskiy et Lange-Bertalot [2], Gliwiczia Kulikovskiy, Lange-Bertalot et Witkowski [3], Skabitschewskia Kulikovskiy et Lange-Bertalot [4], Platebaikalia Kulikovskiy, Glushchenko, Genkal et Kociolek [5], Gololobovia Kulikovskiy, Glushchenko, Genkal et Kociolek [6] and Platesiberia Kulikovskiy, Glushchenko, Genkal et Kociolek [7]. A comprehensive review and revision of diatoms from Lake Baikal was published in the 2010s [2,4], in which many monoraphid taxa were reported and illustrated, both previously known and new.…”