New data on the mayflies (Ephemeroptera) of North-Western Yakutia

New data on the fauna of mayflies in the Anabar River basin are given. A total of eight species of Ephemeroptera have been identified in the fauna of North-Western Yakutia for the first time. Though the mayfly fauna in this region consists mainly of East Palaearctic species, the only seven of them are characterized by arctic-alpine distribution. In general, mayfly species richness of the studied subarctic and southern rivers of Yakutia is similar.

Candidatus Nitrosopolaris, a genus of putative ammonia-oxidizing archaea with a polar/alpine distribution

Ammonia-oxidizing archaea (AOA) are key players in the nitrogen cycle. Here, we report four novel metagenome-assembled genomes (MAGs) assigned to the genus “UBA10452”, an uncultured lineage of putative AOA in the family Nitrososphaeraceae. Analysis of other eight previously reported MAGs and publicly available amplicon sequencing data revealed that the UBA10452 lineage is predominantly found in acidic polar and alpine soils. We propose a novel Candidatus genus, Ca. Nitrosopolaris, with four species representing clear biogeographical/habitat clusters. In addition to the presence of genes involved in cold adaptation, we hypothesize that the distribution of Ca. Nitrosopolaris across the cold biosphere might also be due to the combination of a polar origin and limited dispersal capabilities throughout geological time.

Arctic-Alpine species in the bryoflora of the Altai-Sayan mountain region

In the bryoflora the Altai-Sayan mountain region, 125 species have a predominantly Arctic-alpine distribution. A table of the locations geo-coordinates and habitat types in EUNI terms is compiled. The most common and rare species have been identified. The peculiarities of ecology and distribution of the species are discussed.

The most latent cladoceran in the Holarctic revealed—sinking Unapertura Sarmaja-Korjonen, Hakojärvi & Korhola, 2000 into the genus Rhynchotalona Norman, 1903 (Branchiopoda: Cladocera: Chydoridae)

The morphology of one of the smallest chydorid cladocerans in the world, Unapertura latens Sarmaja-Korjonen, Hakojärvi & Korhola, 2000 (Branchiopoda: Cladocera: Anomopoda) is studied herein. External features and postabdomen of the adult parthenogenetic female are discussed in detail for the first time, based on an intact specimen from northern Finland. Originally described on Quaternary fossil remains, we investigate the validity of the monotypic genus Unapertura and its position within the Aloninae subfamily, in particular in relation to Rhynchotalona Norman, 1903. As a result, we rename the taxon as Rhynchotalona latens comb. nov., based on morphology. The species, a glacial relict, seems one of the rarest cladocerans in contemporary waters in Finland, yet intact specimens are clearly overlooked and recent remains in surface sediments suggest an Arctic-Alpine distribution in oligotrophic habitats in the Holarctic.

Comparative study of structural and ecophysiological features of lichens of different ecological groups in rocky forest communities of northernmost boreal zone (Karelia, Russia)

The anatomical (thickness of layers of fungal and algal symbionts) and ecophysiological parameters (the content of photosynthetic pigments) of two lichen species (Hypogymnia physodes and Umbilicaria hyperborea) from rocky forest communities of northernmost boreal zone (North-West of Russia) were studied. H. physodes is a lichen with foliose thallus morphology and circumpolar distribution which colonizes almost every substrate. U. hyperborea is strictly epilithic lichen with umbilicate type of thallus morphology and arcto-alpine distribution. Despite the fact that the photobiont in two species are closely related taxa (unicellular green algae of the genus Trebouxia) a high variability of photosynthetic pigments content in H. physodes thalli has been revealed, whereas in U. hyperborea, the mycobiotic showed high structural variability. It can be concluded that both mycobiont and photobiont contribute to their adaptation to environmental factors. In the present study it was obtained that the proportion of variation in anatomical structures and the content of photosynthetic pigments probably less depends on taxonomic position of photobiont and more determined by the plasticity of the individual components of the symbiotrophic organism.

Molecular phylogeny of the Kosciuscola grasshoppers endemic to the Australian alpine and montane regions

Diversity and speciation in Australia’s alpine biota are poorly understood. Here we present a molecular phylogeny of the Australian alpine grasshopper genus Kosciuscola (Sjösted) that currently includes five described species. These grasshoppers are of interest not only because of their alpine distribution but also for the extraordinary colour change exhibited by the species K. tristis, whose males turn turquoise when their body temperature exceeds 25°C. We reconstructed the phylogeny with two fragments of the mitochondrial genome using parsimony, maximum likelihood and Bayesian analyses and our data support the current taxonomy. Further, our data show little geographic structuring within some clades, which is puzzling since members of Kosciuscola are brachypterous. Finally, our data coupled with our observations on colouration provide evidence for a genetically distinct clade of K. tristis in the Victorian Alps. This is among the first molecular studies of an alpine invertebrate and one of a few on non-endangered, widespread Australian alpine species. More phylogenetic studies in the Australian Alps are required if we are to understand the evolution of alpine fauna and establish baseline data to monitor their response to climate change.

ECOPHYSIOLOGY OF SEED GERMINATION IN ENDEMIC LABIATES OF CRETE

Ecophysiological aspects of seed germination were investigated in four aromatic labiate plants of Crete Origanum dictamnus (dittany), Sideritis syriaca L. ssp. syriaca (Cretan mountain tea), Salvia pomifera L. ssp. pomifera (gall-bearing sage), and Salvia fruticosa (three-lobed sage). Experiments were performed both at constant temperatures and darkness as well as under temperature and light conditions simulating those prevailing in nature during the main germination periods (i.e., start and middle of the rainy season, November and February-March, respectively). In three out of the four species, no particular dormancy was revealed and germination occurred rather promptly, although in a rather narrow range of cool temperatures and at a relatively slow rate; both characteristics determine and/or support an early, autumn seed germination and seedling establishment. In the fourth plant, Sideritis syriaca, germination was manifested at relatively warm temperatures and at a considerably faster rate, in accordance with its alpine distribution favoring spring seedling emergence and establishment. All four species tested showed an intermediate response towards light, as a result of their intermediate levels of active phytochrome maintained in darkness. Therefore seed germination was partially manifested in darkness but it was significantly enhanced (particularly at suboptimal temperatures) by white or red light; on the other hand, illumination with far-red light (simulating light conditions under a canopy) resulted in significant inhibition compared to dark controls.