Terrestrial biota in the Antarctic are more globally distinct and highly structured biogeographically than previously believed, but information on biogeographic patterns endemism freshwater communities is largely lacking. We studied of diatoms based analysis species occurrences a dataset 439 lakes spread across realm. Highly diatom floras, both terms composition richness, characterize Continental Antarctica, Maritime Antarctica sub‐Antarctic islands, with marked provincialism each region. A...

Four taxa belonging to the complex of species around Achnanthidium minutissimum were found during ongoing taxonomic revision Antarctic freshwater and limno-terrestrial diatom flora. Two previously described as lailae A. sieminskae. others formerly identified but detailed light scanning electron microscopical observations revealed sufficient morphological differences compared type minutissimum, justify their separation description new taxa: indistinctum maritimo-antarcticum. The morphology...

While conducting surveys of freshwater algae from the Hawai'i Islands, we encountered several diatom species and populations belonging to genus Diadesmis, subgenus Paradiadesmis. Upon closer examination valve morphology with scanning electron microscopy, assigned Paradiadesmis differed considerably in structure microhabitat fidelity Diadesmis confervacea Kützing, type Diadesmis. The have each stria composed a single elongate areola, external distal raphe ends that are straight curved, fine...

Diatom taxa present in the inland streams and lakes of McMurdo Dry Valleys James Ross Island, Antarctica, are presented this paper. A total nine illustrated, with descriptions four new species ( Luticola austroatlantica sp. nov., dolia laeta Muelleria supra nov.). In perennially ice-covered Valleys, diatoms confined to benthic mats within photic zone. streams, attached surfaces microbial mat matrix. One species, L. austroatlantica, is found on southern Atlantic archipelago, Valleys. The...

During a survey of the non-marine diatom flora from lakes on James Ross Island (Maritime Antarctic Region), five new Luticola species have been recorded: desmetii, L. doliiformis, evkae, permuticopsis and tomsui. Detailed morphology descriptions these taxa are given based both light (LM) scanning electron microscopy (SEM). The morphological features each taxon compared with similar notes ecology added.

During the ongoing revision of non-marine diatom flora Livingston Island (South Shetland Islands, Maritime Antarctic Region) taxonomy and morphology all Pinnularia taxa, excluding section Distantes, present in samples from Island, have been analysed. Seventeen different taxa recorded. Apart those previously described Region (P. subcapitata var. elongata, P. gemella, austroshetlandica) Andes strictissima), thirteen unknown found. Based on their unique morphological features, twelve are as new...

Background and aim -The non-marine diatom communities in the Antarctic Region are characterized by a typical species composition, close relationship with their environment.Despite growing interest, flora of James Ross Island is only poorly known.The present paper discusses diversity limnoterrestrial diatoms on this island: seepages streams.Methods 53 samples taken eastern side Ulu peninsula has been studied using light scanning electron microscopy.Key results -A total 69 taxa belonging to 26...

Abstract Diatom and water chemistry samples were collected from 49 lakes, pools rivers on Byers Peninsula (Livingston Island, South Shetland Islands) during the summer of 2009. A diverse diatom flora 143 taxa was found. Fragilaria capucina s.l., Psammothidium papilio , Navicula dobrinatemniskovae several Nitzschia dominated flora. The biogeographical analysis showed that more than 55% all observed presented a restricted Antarctic biogeographic distribution only 30% had cosmopolitan...

Recent morphology-based investigations of freshwater Arctic diatoms suggest that many species remain to be discovered, reflecting a unique polar flora. During survey the diatom flora northern Billefjorden, including Petuniabukta fjord region (Spitsbergen), several morphodemes belonging Achnanthidium minutissimum complex were recorded. Molecular phylogenies based on rbcL, 28S and 18S sequences, single cells from Canada strains Marion Island (sub-Antarctica) GenBank revealed presence 12...

Four monoraphid taxa belonging to the genera Achnanthes, Psammothidium and Planothidium were found during ongoing taxonomic revision of freshwater limno-terrestrial diatoms Maritime Antarctic region. The present paper describes these four as new based on detailed light scanning electron microscopy observations: Achnanthes kohleriana Kopalová, Zidarova & Van de Vijver sp. nov., wetzelectorianum confusoneglectum nov. superpapilio morphology ecology all are discussed species compared with...

We have studied laminated sediments from Lake Esmeralda, Vega Island, in order to reconstruct its history. describe both inorganic and organic components of the sediment using a combination following analytical methods: x-ray fluorescence (XRF), diffraction (XRD), magnetic susceptibility measurement, chemical analysis for determination cation exchange capacity, grain size determination, geochemical analyses (total carbon (TIC), total (TOC), sulphur (TS)), spectrophotometry, high-pressure...

The type material of Achnanthidium lanceolatum (transferred in 1999 to the genus Planothidium) is investigated reveal identity several Planothidium populations from Antarctic Region.The morphology and ultrastructure was analysed using light scanning electron microscopy.The results this analysis revealed presence two so far undescribed species material.Both are described as new science: P. rostrolanceolatum Van de VijVer, KopaloVá et zidaroVa sp.nov.and subantarcticum VijVer c.e.Wetzel...

A revision of the freshwater diatom genus Luticola from McMurdo Sound Region, including Dry Valleys and Cape Royds, Antarctica, was made to contribute a consistent flora for entire Antarctic Region. Detailed light scanning electron microscopic observations, review pertinent literature, examination historical type material lead identification 12 species. Four new species one combination are proposed, L. bradyi sp. nov., spainiae, macknightiae, transantarctica, elegans, comb. nov. stat....

Background and aims – The Maritime Antarctic vegetation is a poorly developed tundra dominated by lichens mosses, mostly present in moist environments, providing favourable habitat for microorganisms. Although, diatoms represent one of the most common algal groups region, moss-inhabiting are rarely studied. moss on islands region forms favorable non-marine diatoms. These diatom communities particular interest as little known about their species composition, ecological preferences habitats....

Abstract Lentic freshwater habitats are important centres of biodiversity within the infrequent ice-free oases across Antarctica. Given imminent climate changes, it is crucial to catalogue these in order provide baseline data for future monitoring and biological surveys. The lacustrine systems Clearwater Mesa, a previously unexplored part James Ross Island, north-eastern Antarctic Peninsula, described here. We conducted basic geomorphological limnological surveys over three summers (2009–16)...

The purpose of this study was to present LM and SEM observations Nitzschia taxa encountered on the South Shetland Islands James Ross Island.During ongoing taxonomical revision freshwater limno-terrestrial diatom flora Island (Maritime Antarctic Region) eight unknown belonging genus were found.These previously forcefitted into European names such as N. commutata or perminuta, but detailed light scanning electron microscopical allowed their separation from already known resulted in description...

Lentic waterbodies provide terrestrial sedimentary archives of palaeoenvironmental change in deglaciated areas the Antarctic. Knowledge long-term evolution Antarctic palaeoenvironments affords important context to current marked impacts climate Polar regions. Here, we present a comprehensively dated, multi-proxy record from Monolith Lake, distal proglacial lake one largest ice-free Peninsula region. Of two defined units cores studied, lower Unit 1 exhibits homogeneous composition and...

A recent survey of the non-marine diatoms from seepage areas on James Ross Island (Antarctic Peninsula Region) resulted in discovery three new diatom species belonging to genera Diadesmis, Eolimna and Luticola. Based both light scanning electron microscopical observations, these were described as science: Diadesmis inconspicua sp. nov., jamesrossensis nov. Luticola truncata The morphology each was compared similar worldwide with a special focus those present Antarctic Region. Notes ecology added.

Abstract A recent survey of the non-marine diatoms from islands in Atlantic sector Southern Ocean (King George Island, Deception Livingston James Ross Signy South Georgia and Beak Island) resulted description four new diatom species: Chamaepinnularia gerlachei Van de Vijver & Sterken sp. nov., Craticula antarctica Sabbe subpampeana nov. Diadesmis australis The morphology each species is described on basis light electron microscopy. are compared to similar taxa, especially those present...