Analysis of the type material of **Achnanthidium lanceolatum** Brébisson ex Kützing (Bacillariophyta) with the description of two new **Planothidium** species from the Antarctic Region

• Published in: Fottea
• Main Authors: Van de Vijver, Bart, Wetzel, Carlos, Kopalová, Kateřina, Zidarova, Ralitsa, Ector, Luc
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2013
• Subjects: Biology; Antarctic; The Antarctic; Antarc*
• Online Access: https://hdl.handle.net/10067/1121920151162165141

Abstract: The type material of Achnanthidium lanceolatum (transferred in 1999 to the genus Planothidium) is investigated to reveal the identity of several Planothidium populations from the Antarctic Region. The morphology and the ultrastructure was analysed using light and scanning electron microscopy. The results of this analysis revealed the presence of two so far undescribed Planothidium species in the investigated Antarctic material. Both species are described as new to science: P rost-rolanceolatum VAN DE VIJVER, KOPALOVA et ZIDAROVA Sp. nov. and P subantarcticum VAN DE VuvER et C.E.WETzEL sp. nov. The new species can be differentiated based on differences in valve outline and the shape and size of the central area. Planothidium lanceolatum is formally lectotypified. Notes on the ecology and distribution of the new Antarctic species are added.