The tanaidacean fauna of the Beagle Channel (southern Chile) and its relationship to the fauna of the Antarctic continental shelf

2001 ◽  
Vol 13 (4) ◽  
pp. 420-429 ◽  
Author(s):  
Anja Schmidt ◽  
Angelika Brandt
Keyword(s):  
Adjacent Area ◽  
Systematic Account ◽  
Bathymetric Range ◽  
Beagle Channel ◽  
Epibenthic Sledge ◽  
Magellan Strait ◽  
Antarctic Continental Shelf ◽  
Magellan Region ◽  
The Antarctic ◽  
First Time

In November 1994 epibenthic sledge samples were taken in the Beagle Channel. This study presents the first systematic account of Tanaidacea of the Beagle Channel and an adjacent area on the Atlantic continental slope. The material of this part from the Magellan Strait comprised 2175 specimens and 27 species of eight families of Tanaidomorpha and two families of Apseudomorpha. Eleven species were sampled in the Magellan region for the first time. The genus Stenotanais (Anarthruridae) was reported for the first time in the Southern Hemisphere and, the bathymetric range of seven species was extended. The tanaidacean fauna in the Beagle Channel is highly heterogeneous with 36 tanaidacean species now known from the Magellan region. On the basis of a zoogeographic comparison of the Magellan region with sub-Antarctica and Antarctica, Sieg's (1988) hypothesis of a phylogenetically young, derived Antarctic tanaidacean fauna is examined and the zoogeographic relationship between the Magellanic Tanaidacea and the Antarctic tanaidaceans is discussed.

Stylasterids (Hydrozoa: Stylasteridae) from Mar del Plata submarine canyon and adjacent area (southwestern Atlantic), with a key to the species off Argentina

Zootaxa ◽  
2021 ◽  
Vol 4969 (3) ◽  
pp. 401-452
Author(s):  
M.C. BERNAL ◽  
S.D. CAIRNS ◽  
P.E. PENCHASZADEH ◽  
D. LAURETTA
Keyword(s):  
South Africa ◽  
New Zealand ◽  
New Caledonia ◽  
Submarine Canyon ◽  
Adjacent Area ◽  
Southwestern Atlantic ◽  
Antarctic Region ◽  
Bathymetric Range ◽  
Deep Waters ◽  
The Antarctic

The Argentine continental margin is a poorly explored area as regards its benthic biodiversity. Few works have been made near the Brazil-Malvinas confluence (around 38° S) regarding corals, especially in deep waters (over 1000 m). Hitherto 17 species of stylasterids are known from southwestern Atlantic (SWA) off Argentina. Fourteen species of stylasterids collected from the Mar del Plata submarine canyon and adjacent area in years 2012 and 2013 at depths between 800 and 2200 m are discussed, including the descriptions of 13 of them. The geographic distribution of six species and bathymetric range of occurrence of two species are broadened in this work. Stations where most specimens were collected are located in areas where sedimentation is known to be scarce. Species in common between the study area and the Antarctic region, south of Chile, South Africa, New Zealand and New Caledonia suggest the Circumpolar Antarctic Current and the Malvinas Current are the means for dispersion. A key of identification of all stylasterid species off Argentina is included. 

scholarly journals On some shallow-water Tanaidomorpha (Crustacea: Peracarida: Tanaidacea) of Chilean fjords, with description of a new species of Zeuxoides Sieg, 1980

Zootaxa ◽  
2012 ◽  
Vol 3257 (1) ◽  
pp. 38 ◽  
Author(s):  
PATRICIA ESQUETE ◽  
ROGER BAMBER ◽  
CRISTIAN ALDEA
Keyword(s):  
New Species ◽  
Shallow Water ◽  
Intraspecific Variation ◽  
Beagle Channel ◽  
Magellan Strait ◽  
First Time ◽  
Interspecific And Intraspecific Variation ◽  
Rocky Bottoms ◽  
A New Species

Magellanic tanaidacean faunas have been mainly studied in the Magellan Strait and Beagle Channel, the latter restricted to bot-toms deeper than 40m. As a result, the shallow rocky bottoms of the Magellanic fjords remain largely under-studied, and theirtanaidacean diversity is poorly known. In this study, tanaidacean species sampled from shallow rocky bottoms of Chilean fjordsare investigated, and morphological and taxonomic considerations included. A new species of the Tanaidae, Zeuxoides tronco-soi sp. nov. is described. The genus Leptochelia is recorded for the first time in Chile, and the distribution of Pancoloides lito-ralis is extended northwards. Specimens collected of Pancoloides litoralis and Nototanais dimorphus present morphologicaldifferences with previous descriptions, which are at present attributed to intraspecific variation derived from geographical iso-lation among populations, until sufficient material can be examined to determine what constitutes interspecific and intraspecific variation.

Sponges of the Lazarev and Weddell Sea, Antarctica: explanations for their patchy occurrence

1995 ◽  
Vol 7 (3) ◽  
pp. 227-234 ◽  
Author(s):  
Julian Gutt ◽  
Vladimir M. Koltun
Keyword(s):  
Continental Shelf ◽  
Weddell Sea ◽  
Small Scale ◽  
Atlantic Sector ◽  
Investigation Area ◽  
Antarctic Continental Shelf ◽  
The Individual ◽  
Environmental Events ◽  
The Antarctic ◽  
First Time

Seventy-three sponge species were caught at 23 stations on the continental shelf of the Lazarev and Weddell Sea (Atlantic sector of the Southern Ocean). Tedania tantula was the most often found species amongst the 63 demosponge species caught and among the five hexactinellid species Rossella racovitzae was most common. The stations were classified according to their species inventory, and so the individual stations of the resulting four groups were rather uniformly dispersed over the entire investigation area. The species composition of adjacent stations varied considerably. There was no discernible relationship between the biological set of data and any combination of the available environmental characteristics of the stations. The sponge fauna of the, so far very poorly investigated, Lazarev Sea did not differ considerably from that of the adjacent Weddell Sea. The only species to be recorded for the first time on the Antarctic continental shelf were Homaxinella flagelliformis and Hyrtios arenosa. Small scale environmental events such as iceberg scouring, or biological characteristics such as extremely slow growth and budding reproduction are thought to generate the patchy distribution pattern.

Lichens of the Oasis Molodyozhnyi and adjacent areas (Enderby Land, Antarctic)

2013 ◽  
Vol 47 ◽  
pp. 167-178 ◽  
Author(s):  
M. P. Andreev
Keyword(s):  
Liquid Water ◽  
Climate Conditions ◽  
Water Ice ◽  
Buellia Frigida ◽  
Antarctic Continent ◽  
Harsh Climate ◽  
The Antarctic ◽  
First Time ◽  
Lichen Flora

Lichen flora and vegetation in the vicinity of the Russian base «Molodyozhnaya» (Enderby Land, Antarctica) were investigated in 2010–2011 in details for the first time. About 500 specimens were collected in 100 localities in all available ecotopes. The lichen flora is the richest in the region and numbers 39 species (21 genera, 11 families). The studied vegetation is very poor and sparse, but typical for coastal oases of the Antarctic continent. The poorness is caused by the extremely harsh climate conditions, insufficient availability of liquid water, ice-free land, and high insolation levels. The dominant and most common lichens are Rinodina olivaceobrunnea, Amandinea punctata, Candelariella flava, Physcia caesia, Caloplaca tominii, Lecanora expectans, Caloplaca ammiospila, Lecidea cancriformis, Pseudephebe minuscula, Lecidella siplei, Umbilicaria decussata, Buellia frigida, Lecanora fuscobrunnea, Usnea sphacelata, Lepraria and Buellia spp.

Pathways and timescales of connectivity around the Antarctic continental shelf 

2021 ◽  
Author(s):  
Hannah Dawson ◽  
Adele Morrison ◽  
Veronica Tamsitt ◽  
Matthew England
Keyword(s):  
Continental Shelf ◽  
Ross Sea ◽  
Coastal Current ◽  
West Antarctica ◽  
Source Regions ◽  
Freshwater Forcing ◽  
Antarctic Continental Shelf ◽  
Antarctic Continent ◽  
Antarctic Slope Current ◽  
The Antarctic

<p><span xml:lang="EN-US" data-contrast="auto"><span>The Antarctic margin is surrounded by two westward flowing currents: the Antarctic Slope Current and the Antarctic Coastal Current. The former influences key processes near the Antarctic margin by regulating the flow of heat and nutrients onto and off the continental shelf, while together they </span></span><span xml:lang="EN-US" data-contrast="auto"><span>advect</span></span><span xml:lang="EN-US" data-contrast="auto"><span> nutrients, biological organisms, and temperature and salinity anomalies around the coastline, providing a connective link between different shelf regions. However, the extent to which these currents transport water from one sector of the continental shelf to another, and the timescales over which this occurs, remain poorly understood. Concern that crucial water formation sites around the Antarctic coastline could respond to non-local freshwater forcing </span></span><span><span xml:lang="EN-US" data-contrast="auto"><span>from ice shel</span></span></span><span><span xml:lang="EN-US" data-contrast="auto"><span>f meltwater</span></span></span> <span xml:lang="EN-US" data-contrast="auto"><span>motivates a more thorough understanding of zonal connectivity around Antarctica. In this study, we use daily velocity fields from a global high-resolution ocean-sea ice model, combined with the <span>Lagrangian</span> tracking software Parcels, to investigate the pathways and timescales connecting different regions of the Antarctic continental shelf<span> with a view to understanding</span><span> the timescales of meltwater transport around the continent</span>. Virtual particles are released over the continental shelf, poleward of the 1000 <span>metre</span> isobath, and are tracked for 20 years. Our results show a strong seasonal cycle connecting different sectors of the Antarctic continent, with more particles arriving further downstream during winter than during summer months. Strong advective links exist between West Antarctica and the Ross Sea while shelf geometry in some other regions acts as barriers to transport. We also highlight the varying importance of the Antarctic Slope Current and Antarctic Coastal Current in connecting different sectors of the coastline. Our results help to improve our understanding of circum-Antarctic connectivity <span>and the timescales </span><span>of meltwater transport from source regions to downstream </span><span>shelf locations. </span><span>Further</span><span>more, t</span><span>he timescales and pathways we </span><span>present </span><span>p</span>rovide a baseline from which to assess long-term changes in Antarctic coastal circulation due to local and remote forcing.<br></span></span></p>

scholarly journals Sesquiterpenoids From the Antarctic Fungus Pseudogymnoascus sp. HSX2#-11

2021 ◽  
Vol 12 ◽  
Author(s):  
Ting Shi ◽  
Xiang-Qian Li ◽  
Li Zheng ◽  
Ya-Hui Zhang ◽  
Jia-Jia Dai ◽  
...  
Keyword(s):  
Pathogenic Fungi ◽  
Antibacterial Activities ◽  
Aeromonas Salmonicida ◽  
Systematic Research ◽  
Cytotoxic Activities ◽  
Hepg2 Cell Lines ◽  
New Compounds ◽  
The Antarctic ◽  
First Time ◽  
Hepatoma Hepg2

The fungal strains Pseudogymnoascus are a kind of psychrophilic pathogenic fungi that are ubiquitously distributed in Antarctica, while the studies of their secondary metabolites are infrequent. Systematic research of the metabolites of the fungus Pseudogymnoascus sp. HSX2#-11 led to the isolation of six new tremulane sesquiterpenoids pseudotremulanes A–F (1–6), combined with one known analog 11,12-epoxy-12β-hydroxy-1-tremulen-5-one (7), and five known steroids (8–12). The absolute configurations of the new compounds (1–6) were elucidated by their ECD spectra and ECD calculations. Compounds 1–7 were proved to be isomeride structures with the same chemical formula. Compounds 1/2, 3/4, 1/4, and 2/3 were identified as four pairs of epimerides at the locations of C-3, C-3, C-9, and C-9, respectively. Compounds 8 and 9 exhibited cytotoxic activities against human breast cancer (MDA-MB-231), colorectal cancer (HCT116), and hepatoma (HepG2) cell lines. Compounds 9 and 10 also showed antibacterial activities against marine fouling bacteria Aeromonas salmonicida. This is the first time to find terpenoids and steroids in the fungal genus Pseudogymnoascus.

The United Nations and Antarctica, 1994: the restoration of consensus?

Polar Record ◽  
1995 ◽  
Vol 31 (179) ◽  
pp. 419-424 ◽  
Author(s):  
Peter J. Beck
Keyword(s):  
United Nations ◽  
Major Change ◽  
International Community ◽  
Consensus Approach ◽  
Future Role ◽  
Change Of Direction ◽  
Antarctic Treaty ◽  
Environment And Development ◽  
The Antarctic ◽  
First Time

ABSTRACTThe twelfth successive UN session on the ‘Question of Antarctica,’ held at the close of 1994, saw a major change of direction. One brief session of the First Committee, followed by the General Assembly's adoption of resolution A49/80 without a vote, signified the restoration of a consensus approach towards the ‘Question of Antarctica’ for the first time since 1985. Resolution A49/80 stressed the need for Antarctic Treaty Parties (ATPs) to meet commitments undertaken at the 1992 United Nations Conference on Environment and Development, and particularly to continue providing the wider international community with information about Antarctic developments. The ‘Question of Antarctica’ will not be placed on the UN agenda again until 1996, thereby breaking the sequence of annual UN discussions started in 1983. On the surface, consensus was restored, but it is debatable how far the outcome represented merely a papering over of the cracks rather than the basis for an enduring solution to the problems dividing ATPs and their critics. The key point at issue remains the nature and extent of the UN's future role in Antarctic affairs, particularly as ATPs will only accept a limited UN role performed within the context of the Antarctic Treaty System.

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