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The pan‐Antarctic distributions of several collembolan species have been supported by morphology for over 120 years. However, for most species where molecular data are available, these are now known to belong instead to several species, and most classified as short‐range endemics. One such species, Friesea grisea, had a pan‐Antarctic distribution that has been in question, but until recently, specimens of F. grisea from the type locality on South Georgia have not been included in any molecular appraisal. Here, we compare the molecular identity of specimens of F. grisea, from South Georgia, with other Antarctic and sub‐Antarctic species using the mitochondrial COI gene. A Bayesian phylogenetic analysis for 14 species of Friesea from southern regions, including F. grisea sensu stricto with species previously identified as 'F. grisea' (F. antarctica, F. gretae and F. propria) confirms the distinctness of the South Georgian specimens based on molecular data, and these results are confirmed morphologically. The genus Friesea is one of the most speciose genera of Collembola known in the Antarctic region, and we provide an annotated key (dichotomous and interactive versions) to all Friesea species in the sub‐Antarctic and Antarctica. We compare the biogeography of Friesea to other Collembola from the region to highlight our current understanding of species boundaries and island linkages. [ABSTRACT FROM AUTHOR]

Antarctica contains some of the most challenging environmental conditions on the planet due to freezing temperatures, prolonged winters and lack of liquid water. Whereas 99.7% of Antarctica is permanently covered by ice and snow, some coastal areas and mountain ridges have remained ice-free and are able to sustain populations of microinvertebrates. Tardigrades are one of the more dominant groups of microfauna in soil and limno-terrestrial habitats, but little is known of their diversity and distribution across Antarctica. Here, we examine tardigrades sampled from across an extensive region of continental Antarctica, and analyse and compare their partial mitochondrial cytochrome c oxidase subunit 1 (COI) gene sequences with those from the Antarctic Peninsula, maritime and sub-Antarctica, Tierra del Fuego and other worldwide locations in order to recognise operational taxonomic units (OTUs). From 439 new tardigrade COI sequences, we identified 98 unique haplotypes (85 from Antarctica) belonging to Acutuncus, Diphascon, Echiniscus, Macrobiotus, Milnesium and unidentified Parachela. Operational taxonomic units were delimited by Poisson tree processes and general mixed Yule coalescent methods, resulting in 58 and 55 putative species, respectively. Most tardigrades appear to be locally endemic (i.e. restricted to a single geographic region), but some (e.g. Acutuncus antarcticus (Richters, 1904)) are widespread across continental Antarctica. Our molecular results reveal: (i) greater diversity than has previously been appreciated with distinct OTUs that potentially represent undescribed species, and (ii) a lack of connectivity between most OTUs from continental Antarctica and those from other Antarctic geographical zones. [ABSTRACT FROM AUTHOR]

Molecular variation among Antarctic Collembola has been well appreciated over the last decade. The majority of studies have focussed on the Transantarctic Mountains and Antarctic Peninsula, and more recently Dronning Maud Land, which now accounts for all known continental species. Within most species, mean mitochondrial DNA (mtDNA) sequence divergence has not been more than around 2%, but in 2010 far greater levels of infraspecific sequence divergence (9.2–10.9%) were discovered in three species:Friesea grisea(10.2%),Gressittacantha terranova(10.4%) andCryptopygus antarcticus(9.2%). Here, we present the first phylogeographic study onCryptopygus sverdrupifrom Dronning Maud Land. We found that mtDNACOIand16Shaplotypes clustered into two lineages with a meanCOIsequence divergence of around 7.1%. The mixing of haplotypes between nearby nunataks separated by up to 15 km revealed support for ongoing (but rare) dispersal, although a single site, the most geographically isolated (by 40–58 km) was also the most genetically divergent. These levels of sequence divergence indicate persistence of biota throughout the Miocene and Pliocene isolated in glacial refugia. Expanding sampling ofC. sverdrupifrom additional ice-free refugia throughout Dronning Maud Land will be important to further our understanding of the evolutionary processes that have influenced the Antarctic continent, its landscape and biota. [ABSTRACT FROM PUBLISHER]

Recent studies have suggested that some resident Antarctic biota are of ancient origin and may have been isolated for millions of years. The phylum Tardigrada, which is part of the Antarctic terrestrial meiofauna, is of particular interest due to an impressive array of biochemical abilities to withstand harsh environmental conditions. Tardigrades are one of the few widespread Antarctic terrestrial animals that have the potential to be used as a model for evolution and biogeography on the Antarctic continent. We isolated 126 individual tardigrades from four geographically isolated soil samples from two remote nunataks in the êslash;r Rondane Mountains, Dronning Maud Land, Antarctica. We examined genetic variation among individuals utilising three gene regions: cytochrome c oxidase subunit I gene (COI), 18S rDNA (18S), and the wingless (Wg) gene. Comparison of sequences from worldwide and Antarctic tardigrades indicated long-term survival and isolation over glacially dominated periods in ice-free habitats in the êslash;r Rondane Mountains. [ABSTRACT FROM AUTHOR]

Gomphiocephalus hodgsoni Carpenter was only the second collembolon to be described from the Antarctic continent. It was collected first in 1902 from Granite Harbour, southern Victoria Land, Eastern Antarctica, by the British National Antarctic Expedition (1901-1904). Since then several studies have investigated the distribution, ecology, ecophysiology and molecular composition of the species. Despite two morphological redescriptions and an absence of detailed evolutionary phylogenetic studies, the genus Gomphiocephalus was recently reduced to a subgenus of Schoettella Schäffer. Here, we redescribe the species in detail and use morphological and molecular (cytochrome c oxidase subunit I and 28S) data to indicate its generic relationships within Hypogastruridae. Characters of Gomphiocephalus do not conform with those of any extant genus in the family, including Schoettella. In addition, the only Schoettella species described from the southern hemisphere, Schoettella subcorta Salmon, is shown here to belong in the genus Xenylla. Furthermore, molecular data indicates the genus has no close relationship to any other in Poduromorpha, and in particular Hypogastruridae. Therefore, we restore Gomphiocephalus to generic status. Our results reinforce the already recognized high level of endemism in the Antarctic fauna at both species and generic levels, and emphasise the necessity of using both morphological and molecular data in determining the systematics and evolutionary relationships of the fauna. [ABSTRACT FROM AUTHOR]