scholarly journals Ultrastructure of Lobosphaera reniformis (Watanabe) Komárek et Fott (Chlorellales) from King George Island, South Shetland Islands, Antarctica

2014 ◽  
Vol 63 (2) ◽  
pp. 205-210 ◽  
Author(s):  
A. Massalski ◽  
T. Mrozińska ◽  
M. Olech

<i>Lobosphaera reniformis</i> (Wat.) Kom. et Fott (=<i>Chlorella reniformis</i> Wat.) so far known only from Japan, and Papua Island, was for the first time found in Antarctica (King George Island, South Shetland Islands). In laboratory cultures a complete life cycle was obtained, and most of its stages were followed by the electron microscopy. Reproduction is by morphologically different autospores. In some large vegetative cells two Golgi apparatuses lying side by side were observed.

2017 ◽  
Vol 38 (3) ◽  
pp. 409-419
Author(s):  
Karol Zemko ◽  
Krzysztof Pabis ◽  
Jacek Siciński ◽  
Magdalena Błażewicz

AbstractAdmiralty Bay (King George Island) is an Antarctic Specially Managed Area and one the most thoroughly studied small-scale marine basins in the Southern Ocean. Our study provides new data on the isopod fauna in this glacially affected fjord. Twelve species of isopods were recorded in this basin for the first time. Six of them were found for the first time in the region of the South Shetland Islands. The highest number of species new for Admiralty Bay were found in the families Munnopsidae (4 species) and Munnidae (3 species).


2018 ◽  
Vol 87 (4) ◽  
Author(s):  
Mariusz Wierzgoń ◽  
Tomasz Suchan ◽  
Michał Ronikier

<em>Tortella fragilis</em> (Drumm.) Limpr. (Pottiaceae) and <em>Bryum nivale</em> Müll. Hal. (Bryaceae) are recorded for the first time from the South Shetland Islands in the northern maritime Antarctic. They were discovered in the Admiralty Bay area on King George Island, the largest island of this archipelago. The two species are briefly characterized morphologically, their habitats are described, and their distribution in the Antarctic is mapped. Discovery of these species has increased the documented moss flora of King George Island to 67 species, strengthening it in the leading position among individual areas with the richest diversity of moss flora in Antarctica. Likewise, <em>T. fragilis</em> and <em>B. nivale</em> represent remarkable additions to the moss flora of the South Shetland Islands, which currently consists of 92 species and one variety, making this archipelago by far the richest bryofloristically amongst large geographic regions of the Antarctic. Comparison of recent (2018) and old (1985) photographs revealed a significant retreat of glacial cover and suggests that the collection site was likely opened for colonization only within the last several decades. The record of <em>T. fragilis</em> is biogeographically relevant, and constitutes an intermediate site between the species’ occurrences in the Antarctic Peninsula and southern South America. The present record of <em>B. nivale</em> is the fourth discovery of the species worldwide, which may be helpful for the future designation of the distribution of this extremely rare species.


2020 ◽  
Vol 47 (8) ◽  
pp. 6379-6384
Author(s):  
Marta Potocka ◽  
Ewa Krzemińska ◽  
Robert Gromadka ◽  
Jan Gawor ◽  
Joanna Kocot-Zalewska

Abstract Trichocera maculipennis, an invasive Diptera, was described for the first time in Antarctica in 2006 in a sewage system of one of the scientific stations on King George Island, South Shetland Islands, and started to increase its distribution within the island. To date, only taxonomical description of this species, based on morphological data has been available, as there were no molecular data recorded. In the present study, we present two methods of molecular identification of this species—based on partial cytochrome c oxidase subunit I (COI) and 16S ribosomal RNA (16S) genes. An appropriate and easy-to-use assay for proper and fast identification of invasive species is a key requirement for further management decisions, especially in such a fragile environment as found in terrestrial Antarctica.


2015 ◽  
Vol 36 (2) ◽  
pp. 163-174
Author(s):  
Joanna Czerwik-Marcinkowska ◽  
Andrzej Massalski ◽  
Maria Olech ◽  
Anna Wojciechowska

Abstract This paper offers a comparison of Muriella decolor specimens from different geographical regions and habitats (limestone caves in Poland and ice denuded areas near the Ecology Glacier, King George Island, South Shetland Islands, West Antarctic). Morphological and cytological variability, ecology and life strategies of M. decolor were studied in fresh samples, and also in cultures grown on agar plates. The complete life cycle, with detailed ultrastructural (LM and TEM) analysis are presented. The electron microscopic observations prove that materials identified as M. decolor collected in Poland and the Antarctic have distinct ultrastructural features. These include the chloroplast lamella arrangement, mitochondrial cristae structure and the cell wall thickness.


2020 ◽  
Vol 10 (2) ◽  
pp. 281-296
Author(s):  
Götz Palfner ◽  
Josefa Binimelis-Salazar ◽  
Sandra Troncoso Alarcón ◽  
Gustavo Torres-Mellado ◽  
Gloria Gallegos ◽  
...  

Relatively few macrofungi have been historically described from terrestrial environments of the Antarctic Peninsula and its associated archipelagos which are characterized by a moss-dominated vegetation, most of them preferentially or obligatorily associated with bryophytes. During the study of the influence of penguin rockeries to moss communities on the South Shetland Islands, the bryophilous basidiomycetes Rimbachia bryophila and Arrhenia cf. lilacinicolor were found for the first time on King George Island, growing on carpets of Sanionia uncinata. Other bryophilous fungi previously recorded in the same region are Arrhenia antarctica, Omphalina pyxidata and the rare Simocybe antarctica. The detection of the supposedly parasitic R. bryophila, together with other new observations of macrofungi on different hosts in the Antarctic bryoflora could indicate increased sexual reproduction. The likely increase of reproduction as an effect of warming on the terrestrial antarctic tundra should be proven by follow up field studies.


2021 ◽  
pp. 1-10
Author(s):  
Micheline Carvalho-Silva ◽  
Luiz Henrique Rosa ◽  
Otávio H.B. Pinto ◽  
Thamar Holanda Da Silva ◽  
Diego Knop Henriques ◽  
...  

Abstract The few Antarctic studies to date to have applied metabarcoding in Antarctica have primarily focused on microorganisms. In this study, for the first time, we apply high-throughput sequencing of environmental DNA to investigate the diversity of Embryophyta (Viridiplantae) DNA present in soil samples from two contrasting locations on Deception Island. The first was a relatively undisturbed site within an Antarctic Specially Protected Area at Crater Lake, and the second was a heavily human-impacted site in Whalers Bay. In samples obtained at Crater Lake, 84% of DNA reads represented fungi, 14% represented Chlorophyta and 2% represented Streptophyta, while at Whalers Bay, 79% of reads represented fungi, 20% represented Chlorophyta and < 1% represented Streptophyta, with ~1% of reads being unassigned. Among the Embryophyta we found 16 plant operational taxonomic units from three Divisions, including one Marchantiophyta, eight Bryophyta and seven Magnoliophyta. Sequences of six taxa were detected at both sampling sites, eight only at Whalers Bay and two only at Crater Lake. All of the Magnoliophyta sequences (flowering plants) represent species that are exotic to Antarctica, with most being plausibly linked to human food sources originating from local national research operator and tourism facilities.


Polar Record ◽  
2000 ◽  
Vol 36 (196) ◽  
pp. 3-18 ◽  
Author(s):  
P. Prosek ◽  
M. Janouch ◽  
K. Láska

AbstractThis article presents the results of measurements of the components of ground-surface energy balance (radiation balance, sensible heat flux, latent heat flux, and ground heat flux) taken during the 1994/95 summer season at Poland's Henryk Arctowski Station, King George Island, South Shetland Islands (62°09'42”S, 58°28'10”W). This was the first time that these complex measurements had been taken in the central part of the South Shetlands archipelago. The results are evaluated at the level of daily and seasonal fluctuations. The consequences of energy balance on the temperature conditions of the soil substrata are highlighted. The verification of the degree of influence of a subset of energy-balance components on soil temperature allowed analysis of the relationships among soil temperature, radiation balance, and sensible heat flux. This analysis leads to the conclusion that there is a rapid reaction of the soil temperature to the radiation balance and sensible heat flux to a depth of 5 cm. The boundary atmosphere and soil substrate represent the basic components of the ecotops of the Antarctic vegetation oasis, so these results are interpreted in pedological or botanical studies in the search for environmental influences on the vegetation.


2009 ◽  
Vol 21 (5) ◽  
pp. 439-448 ◽  
Author(s):  
Wojciech Majewski ◽  
Andrzej Tatur

AbstractCribroelphidium webbi sp. nov. is the only adequately described sub-Recent elphidiid foraminifer from Antarctica. In Admiralty Bay (King George Island, South Shetland Islands), it is found at several locations within inner fiord setting at water depths between 33 and 165 m, but most commonly shallower than 100 m. In outer basins this foraminifer is absent. In the cores analysed, C. webbi sp. nov. is present in well-constrained sub-Recent horizons that are clearly related to climate warming and deglaciation. These horizons represent a diachronous facies marker rather than a single stratigraphic layer. Cribroelphidium webbi sp. nov. shows clear association with retreating tidewater glaciers, therefore it is an important sensitive glacier-proximal indicator. It appears that it shares similar ecologic affinities with Cribroelphidium excavatum clavatum, which is widely distributed throughout the Arctic.


2021 ◽  
pp. 1-9
Author(s):  
Paulo E.A.S. Câmara ◽  
Láuren M.D. De Souza ◽  
Otávio Henrique Bezerra Pinto ◽  
Peter Convey ◽  
Eduardo T. Amorim ◽  
...  

Abstract Antarctic lakes have generally simple periphyton communities when compared with those of lower latitudes. To date, assessment of microbial diversity in Antarctica has relied heavily on traditional direct observation and cultivation methods. In this study, sterilized cotton baits were left submerged for two years in two lakes on King George Island and Deception Island, South Shetland Islands (Maritime Antarctic), followed by assessment of diversity by metabarcoding using high-throughput sequencing. DNA sequences of 44 taxa belonging to four kingdoms and seven phyla were found. Thirty-six taxa were detected in Hennequin Lake on King George Island and 20 taxa were detected in Soto Lake on Deception Island. However, no significant difference in species composition was detected between the two assemblages (Shannon index). Our data suggest that metabarcoding provides a suitable method for the assessment of periphyton biodiversity in oligotrophic Antarctic lakes.


Sign in / Sign up

Export Citation Format

Share Document