Biogeography of the genus Luticola in the Antarctic region

VAN DE VIJVER, BART; KOPALOVÁ, KATERINA; MATALONI, GABRIELA

Dubrovnik, Croacia

Simposio; 20th International Diatom Symposium; 2008

International Society for Diatom Research

The genus Luticola is one of the dominant genera in the terrestrial and semi-aquatic ecosystems in the Antarctic Region, both in number of species as in number of individuals.  Misidentifications in the past have led to the incorrect conclusion that the Luticola flora in this region was far from being typical and comprised only cosmopolitan taxa such as Luticola mutica (Kützing) Mann. Even the most common species, Luticola muticopsis (Van Heurck) Mann, was very frequently misidentified, and this resulted in the attribution of a too large morphological variability to this species. Therefore, a thorough revision of species of this genus actually present in the Antarctic Region was necessary. During an ongoing biogeographical study of the Antarctic non-marine diatom flora, a great number of specimens, formerly attributed to L. mutica and L. muticopsis were found and studied using both light (LM) and scanning electron microscopy (SEM). This resulted in the description of several new species presenting restricted biogeographies in either the southern Indian or southern Atlantic oceans.  This poster presents a picture and description of Luticola muticopsis s.s. from the Van Heurck type slide, together with some of the new species that were recently described from Deception Island, James Ross Island and the Antarctic Continent. , The biogeography of the genus Luticola in the entire Antarctic Region is analysed on the basis of these new taxonomical results, showing a clear distinction between the flora of the southern Indian and the Atlantic Ocean. Typical cosmopolitan species such as L. mutica are almost completely absent.