%0 Journal Article %J Ecography %D 2021 %T Diatoms define a novel freshwater biogeography of the Antarctic %A Elie Verleyen %A Bart Van de Vijver %A Tytgat, Bjorn %A Pinseel, Eveline %A Hodgson, Dominic A. %A Kopalová, Kateřina %A Steven L. Chown %A Van Ranst, Eric %A Imura, Satoshi %A Kudoh, Sakae %A Van Nieuwenhuyze, Wim %A Sabbe, Koen %A Vyverman, Wim %K Antarctica %K biogeography %K diatoms %K endemism %K freshwater %K lake %X

Terrestrial biota in the Antarctic are more globally distinct and highly structured biogeographically than previously believed, but information on biogeographic patterns and endemism in freshwater communities is largely lacking. We studied biogeographic patterns of Antarctic freshwater diatoms based on the analysis of species occurrences in a dataset of 439 lakes spread across the Antarctic realm. Highly distinct diatom floras, both in terms of composition and richness, characterize Continental Antarctica, Maritime Antarctica and the sub-Antarctic islands, with marked biogeographic provincialism in each region. A total of 44% of all species is estimated to be endemic to the Antarctic, and most of them are confined to a single biogeographic region. The level of endemism significantly increases with increasing latitude and geographic isolation. Our results have implications for conservation planning, and suggest that successful dispersal of freshwater diatoms to and within the Antarctic is limited, fostering the evolution of highly endemic diatom floras.

%B Ecography %V 44 %P 1-13 %8 01/2021 %G eng %U https://onlinelibrary.wiley.com/doi/10.1111/ecog.05374 %R 10.1111/ecog.05374 %0 Journal Article %J Limnology and Oceanography Letters %D 2021 %T From the Heroic Age to today: What diatoms from Shackleton's Nimrod expedition can tell us about the ecological trajectory of Antarctic ponds %A Tyler J. Kohler %A Howkins, Adrian %A Eric R. Sokol %A Kopalová, Kateřina %A Cox, Aneliya %A Darling, Joshua P. %A Michael N. Gooseff %A Diane M. McKnight %X

Biological invasion and environmental change pose major threats to ecosystems. While long-term ecological change is commonly evaluated through sediment cores in lakes, it is generally not feasible for smaller ponds, and spatial resolution is limited. Here, we analyze pond diatom communities collected during Shackleton's Nimrod expedition at Cape Royds, Antarctica, to compare with the same waterbodies a century later. We find historical samples to be almost identical to modern counterparts, and provide no evidence of exotic introductions despite increasing human activity. However, a shift occurred in the pond nearest Shackleton's hut, Pony Lake, which was dominated by Luticola muticopsis a century ago, and was replaced by Craspedostauros laevissimus. Both are endemic species previously and currently present at Cape Royds, and we hypothesize that a shift in conductivity accompanying changing precipitation patterns may be responsible. Collectively, these results provide important data for assessing human and climate impacts among Antarctic lacustrine habitats.

%B Limnology and Oceanography Letters %8 07/2021 %G eng %U https://aslopubs.onlinelibrary.wiley.com/doi/10.1002/lol2.10200 %! Limnol Oceanogr %R 10.1002/lol2.10200 %0 Journal Article %J Phytotaxa %D 2019 %T Sabbea gen. nov., a new diatom genus (Bacillariophyta) from continental Antarctica %A Bishop, Jordan %A Kopalová, Kateřina %A Darling, Joshua P. %A Schulte, Nicholas O. %A Tyler J. Kohler %A McMinn, Andrew %A Sarah A. Spaulding %A Diane M. McKnight %A Bart Van de Vijver %K Bacillariophyta %K Cape Royds %K East Antarctica %K McMurdo Dry Valleys %K new genus %K Vestfold Hills %X

The non-marine diatom flora of the Antarctic Continent includes several endemic taxa recorded over the past 100 years. One of these taxa, Navicula adminensis D.Roberts & McMinn, was described from the Vestfold Hills, East Antarctica. Detailed light and scanning electron microscopy observations have shown that based on its morphological features, the species does not belong to the genus Navicula sensu stricto. To determine the most closely related genera to N. adminensis, the morpho- logical features of Adlafia, Kobayasiella, Envekadea, Stenoneis, Berkeleya, Climaconeis, and Parlibellus were compared with those of N. adminensis. Although each of these genera shows one or more similar features, none of them accommodates the salient morphological characteristics of N. adminensis. Therefore, a new genus, Sabbea gen. nov., is herein described, and Navicula adminensis is formally transferred to the new genus as Sabbea adminensis comb. nov. The genus Sabbea is characterized by uniseriate striae composed of small, rounded areolae occluded externally by individual hymenes, a rather simple raphe structure with straight, short proximal ends and short terminal raphe fissures, open girdle bands with double perforation and a very shallow mantle.

%B Phytotaxa %V 418 %8 09/2019 %G eng %U https://www.mapress.com/j/pt/article/view/phytotaxa.418.1.2 %N 1 %R 10.11646/phytotaxa.418.1.2 %0 Journal Article %J Phytotaxa %D 2015 %T The genus Luticola D.G.Mann (Bacillariophyta) from the McMurdo Sound Region, Antarctica, with the description of four new species %A Tyler J. Kohler %A Kopalová, Kateřina %A Bart Van de Vijver %A J. Patrick Kociolek %B Phytotaxa %V 208 %P 103 %8 10/2015 %G eng %U https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.208.2.1 %N 2 %! Phytotaxa %R 10.11646/phytotaxa.208.2.1