The richest diatom complexes have revealed due to the study of glacial-marine sediments sampled in the Fisher Massif (Prince Charles Mountains, East Antarctica) during 52nd and 53rd Russian Antarctic Expeditions (Polar Marine Geol. Survey Expedition) in 2006/07 and 2007/08. Three diatom complexes are distinguished according to different palaeoecological conditions: the planktonic one is located in the basis of the outcrop, while mixed planktonic-benthic and benthic ones being located above. The planktonic diatom complexes are dominated by two oceanic species Actinocyclus ingens (up to 8%) and Denticulopsis simonseni (up to 80%). There are 15 planktonic algae, e. g. Eucampia аntarctica, Fragilariopsis spp., Rhizosolenia spp., Rouxia antarctica, Podosira antarctica sp. nov., Stellarima microtrias; and also unknown and non-described benthic diatoms Achnanthes sp., Cocconeis spp., Rhabdonema (s. l.) spp. and Synedra (s. l.) spp. Detailed data on morphology and taxonomy of 10 centric diatoms are presented, including 3 newly described species.
Bacterial colonization of the freshwater planktonic diatom Fragilaria crotonensis
