Bdelloid rotifers (Bdelloidea, Rotifera) in shallow freshwater ecosystems of Thala Hills, East Antarctica

Abstract Shallow waters, little-studied in Continental Antarctica, among other micrometazoans host bdelloid rotifers, which diversity, ecology, and distributional patterns turn are poorly known. To address these issues, we analysed plankton samples collected during the 2018/2019 season Thala Hills oasis (East Antarctica), shallow freshwater lakes temporary ponds that formed intense snow melting December–January. Bdelloids were present more than 90% of sites with nine species revealed. The most frequent Antarctic endemics [ Philodina gregaria (P. gregaria) , Adineta grandis (A. grandis) coatsi coatsi)] while some non-abundant bdelloids either provide characteristics widely distributed taxa or require further taxonomy studies as they can be new for science. abundance varied greatly across studied localities, a maximum 700,000 ind m −3 an increasing tendency to numerous rock-basin ponds, compared larger lakes, variability different taxa. environmental parameters strongly explain distribution (78.4% variation), important factors being type bottom (9.9%), altitude (8.0%), TDS (6.6%), salinity (6.5%). cyanobacterial mats from didn’t contribute much patterns, despite known preferred habitat including rotifers. These results shape perspective study processes formation seasonal aquatic habitats settled by organisms, demonstrate ecomorphological range planktonic organisms crawling ‘scrapers’.