scholarly journals A brief survey of bryological studies in the Subantarctic, including Macrocoma tenue (Orthotrichaceae), a moss genus and species newly found in Îles Kerguelen

2018 ◽  
Vol 87 (4) ◽  
Author(s):  
Halina Bednarek-Ochyra ◽  
Vítězslav Plášek ◽  
Shui-Liang Guo
Keyword(s):  
Southern Ocean ◽  
First Record ◽  
Global Distribution ◽  
Current State ◽  
Glacial Epoch ◽  
Break Up ◽  
Local Plants ◽  
The Antarctic ◽  
Kerguelen Archipelago ◽  
Ocean Islands

Studies on the bryophyte flora of the Southern Ocean islands and in the Antarctic are briefly reviewed and the current state of knowledge of the moss flora of Îles Kerguelen is discussed. <em>Macrocoma tenue</em> (Hook. &amp; Grev.) Vitt is recorded from the Îles Kerguelen archipelago and this constitutes the first record of the genus <em>Macrocoma</em> (Müll. Hal.) Grout from the Subantarctic. The local plants of the species are characterized and illustrated and their ecology is discussed. Global distribution of <em>M. tenue</em> is reviewed and mapped. It is suggested that the type subspecies of <em>M. tenue</em> is a Gondwanan relictual taxon, which could have evolved on this supercontinent prior to its break-up and, subsequently, it reached Îles Kerguelen where it survived during the Pleistocene glacial epoch.

First record and description of male of Metavargula adinothrix Kornicker, 1975 (Ostracoda: Myodocopina) from the Southern Ocean

Zootaxa ◽  
2010 ◽  
Vol 2434 (1) ◽  
pp. 33 ◽  
Author(s):  
VLADIMIR G. CHAVTUR ◽  
DIETMAR KEYSER ◽  
ALEXANDER G. BASHMANOV
Keyword(s):  
Southern Ocean ◽  
First Record ◽  
Morphological Comparison ◽  
Atlantic Sector ◽  
Male And Female ◽  
The Antarctic ◽  
Unknown Male

Previously unknown male and some juveniles of Metavargula adinothrix Kornicker, 1975 were identified in material which was collected by Germany R/V Polarstern from bathyal and abyssal depth of the Atlantic Sector of the Southern Ocean. Diagnosis, description and detailed illustrations of male of this species are presented. Morphological comparison is made between male and female of this species. The distribution of M. adinothrix in the Antarctic and Subantarctic waters is shown.

scholarly journals First Record of a living Platycopida (Crustacea, Ostracoda) from Antarcticwaters and a Discussion on Cytherella serratula (Brady, 1880)

Zootaxa ◽  
2008 ◽  
Vol 1866 (1) ◽  
pp. 349 ◽  
Author(s):  
SIMONE N. BRANDÃO
Keyword(s):  
New Species ◽  
Southern Ocean ◽  
Intraspecific Variation ◽  
Late Cretaceous ◽  
First Record ◽  
Review Of The Literature ◽  
Antarctic Region ◽  
Fossil Species ◽  
O2 Concentration ◽  
The Antarctic

Previous records of Platycopida (Ostracoda) from the Antarctic region of the Southern Ocean include only a few fossil species from the Late Cretaceous to the Palaeocene: Cytherelloidea megaspirocostata Majoran & Widmark, 1998, [sic] Cytherella serratula (Brady, 1880), plus seven species left in open nomenclature. The present study documents the first record of a living platycopid from the Antarctic region and describes Cytherella rwhatleyi sp. nov. as new. Comparison among specimens collected at stations 60° longitude and 10° of latitude apart from each other show that very little intraspecific variation in outline and ornamentation of the valves, as well as on the hemipenis is presented by this new species. Otherwise, clear differences on valve and hemipenis are observed between different species (herein, Jellinek & Swanson 2003). Review of the literature indicates that several species (with great differences in valve outline and ornamentation) have been erroneously assigned to Cytherella serratula (Brady, 1880) demonstrating that this so-called cosmopolitan taxon is in truth most probably restricted to bathyal depths of the Northwestern Atlantic. Finally, the abundances of Cytherella rwhatleyi sp. nov. in the samples studied herein (considering O2 concentration measurements) contradict the proposed relationship between Platycopida and O2 concentration in water masses (Whatley et al. 2003).

Dikwa andresi, a new amphipod crustacean (Dikwidae) from the Scotia Arc

2003 ◽  
Vol 83 (4) ◽  
pp. 785-788 ◽  
Author(s):  
Anne-Nina Lörz ◽  
Charles Oliver Coleman
Keyword(s):  
New Species ◽  
Southern Ocean ◽  
Water Depth ◽  
Southern Africa ◽  
First Record ◽  
Crustacean Species ◽  
The Family ◽  
Scotia Arc ◽  
Amphipod Crustacean ◽  
The Antarctic

The new amphipod crustacean species Dikwa andresi from the Scotia Arc is described in detail. This is the first record of the family Dikwidae in the Southern Ocean. The white species was caught in water depth of 270–290 metres during the Antarctic autumn, living on the red hydrocoral (Hydrozoa) Errinopsis reticulum. It has a carinate pereon and pleon, no eyes and the head is telescoped into the first pereon segment. The first gnathopod is propodochelate, the second gnathopod is simple. The only known species of the family is Dikwa acrania from southern Africa. The new species mainly differs from D. acrania in having dorsal processes on all pereonites and the first coxa being twice as long as the second. An intraspecific variation of the shape of the telson was observed.

scholarly journals Revision of Leucothoe (Amphipoda, Crustacea) from the Southern Ocean: a cosmopolitanism concept is vanishing

2014 ◽  
Author(s):  
Traudl Krapp-Schickel ◽  
Claude De Broyer
Keyword(s):  
Southern Ocean ◽  
First Record ◽  
Antarctic Species ◽  
Morphological Variants ◽  
The Antarctic

Among the 125 currently recognized species of the panoceanic genus Leucothoe, L. antarctica was described in 1888 from the Antarctic seas, but was soon synonymized with the so-called cosmopolitan Leucothoe spinicarpa Abildgaard, which was cited from the Southern Ocean about 70 times since this first record. After erecting a new Antarctic species again only in 1983, “morphological variants” were observed and discussed. In this paper, we revalidate the first defined Antarctic species (Leucothoe antarctica), redescribe the second one (L. orkneyi), describe 5 new Southern Ocean species (L. campbelli sp. nov., L. longimembris sp. nov., L. macquariae sp. nov., L. merletta sp. nov. and L. weddellensis sp. nov.) and provide a key to all Antarctic and sub-Antarctic species.

scholarly journals Exploring the microdiversity within marine bacterial taxa: Towards an integrated biogeography in the Southern Ocean

2021 ◽  
Author(s):  
G Schwob ◽  
NI Segovia ◽  
CA González-Wevar ◽  
L Cabrol ◽  
J Orlando ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Phylogeographic Structure ◽  
Rrna Gene ◽  
Antarctic Polar Front ◽  
Maritime Antarctica ◽  
Single Strain ◽  
Geographical Regions ◽  
Biogeographic Provinces ◽  
The Antarctic ◽  
Kerguelen Archipelago

AbstractThe phylogeography traditionally correlates the genetic relationships among individuals within a macroorganism species, to their spatial distribution. Most microbial phylogeographic studies so far have been restricted to narrow geographical regions, mainly focusing on isolated strains, either obtained by culture or single-strain natural enrichments. However, the laborious culture-based methodology imposes a low number of studied individuals, leading to poor resolution of haplotype frequency estimation, making difficult a realistic evaluation of the genetic structure of natural microbial populations in the environment.To tackle this limitation, we present a new approach to unravel the phylogeographic patterns of bacteria combining (i) community-wide survey by 16S rRNA gene metabarcoding, (ii) intra-species resolution through the oligotyping method, and (iii) genetic and phylogeographic indices, as well as migration parameters, estimated from populational molecular data as traditionally developed for macroorganisms as models.As a proof-of-concept, we applied this methodology to the bacterial genus Spirochaeta, classically reported as a gut endosymbiont of various invertebrates inhabiting the Southern Ocean (SO), but also described in marine sediment and in open waters. For this purpose, we centered our sampling into three biogeographic provinces of the SO; maritime Antarctica (King George Island), sub-Antarctic Islands (Kerguelen archipelago) and Patagonia in southern South America. Each targeted OTU was chaLRracterized by substantial intrapopulation microdiversity, a significant genetic differentiation and a robust phylogeographic structure among the three distant biogeographic provinces. Patterns of gene flow in Spirochaeta populations support the role of the Antarctic Polar Front (APF) as a biogeographic barrier to bacterial dispersal between Antarctic and sub-Antarctic provinces. Conversely, the Antarctic Circumpolar Current (ACC) appears as the main driver of connectivity between geographically distant sub-Antarctic areas such as Patagonia and Kerguelen archipelago, and between Kerguelen archipelago and maritime Antarctica. Additionnally, we found that historical processes (drift and dispersal limitation) together govern up to 86% of the spatial turnover among Spirochaeta populations. Overall, our approach represents a substantial first attempt to bridge the gap between microbial and macrobial ecology by unifying the way to study phylogeography. We revealed that strong congruency with macroorganisms patterns at the populational level shaped by the same oceanographic structures and ecological processes.

A further assessment of surface temperature changes at stations in the Antarctic and Southern Ocean, 1949–2002

2004 ◽  
Vol 39 ◽  
pp. 331-338 ◽  
Author(s):  
Tim H. Jacka ◽  
William F. Budd ◽  
Andrew Holder
Keyword(s):  
Southern Ocean ◽  
Antarctic Peninsula ◽  
Surface Air Temperature ◽  
Warming Trend ◽  
Temperature Record ◽  
Temperature Changes ◽  
Warming Rate ◽  
Mean Trend ◽  
The Antarctic ◽  
Ocean Islands

AbstractStatistical analyses are carried out, of the annual mean surface air temperature at occupied stations and automatic weather stations in the Antarctic and Southern and Pacific Oceans. The data are studied in four groupings: coastal Antarctica (excluding the Antarctic Peninsula), inland Antarctica, the Antarctic Peninsula and the Southern Ocean/Pacific Ocean islands. We find that within each of these four groupings the average trend indicates warming. For coastal Antarctica the trend is ∼0.8°C(100 a)–1. Inland, the results are less clear, but the mean trend is to a warming of ∼1.0°C(100 a)–1. For the Peninsula stations it is ∼4.4°C(100 a)–1, and for the ocean stations the average trend is ∼0.8°C(100 a)–1. The results indicate a reduction in the warming trend since our last analysis 6 years ago. While the Pinatubo (Philippines) volcanic eruption may have had some influence on this reduction in the warming rate, examination of the interannual variations in the temperature record shows variability has continued high since the recovery from any such effect. There has been a further period of cooler temperatures in coastal and inland Antarctica in that time, yet a warmer period in the Peninsula and ocean islands.

Conservation in the Antarctic

1977 ◽  
Vol 279 (963) ◽  
pp. 97-104 ◽  
Keyword(s):  
Southern Ocean ◽  
Control Measures ◽  
Falkland Islands ◽  
Voluntary Agreement ◽  
South Georgia ◽  
Tristan Da Cunha ◽  
Conservation Measures ◽  
Antarctic Seals ◽  
Antarctic Treaty ◽  
The Antarctic

Formidable legal and administrative complexities arise from conflicting claims to jurisdiction and the continued absence of generally recognized sovereignty over much of the region. Existing conservation measures fall into three groups: elaborate laws made by governments claiming Antarctic territories, more restricted laws, and simple instructions for particular expeditions. The Antarctic Treaty, 1959, made it possible to begin coordinating all these separate instruments. No claimed jurisdiction has been surrendered or recognized: each government has started to harmonize its own control measures with the ‘Agreed Measures for the Conservation of Antarctic Fauna and Flora’, 1964. This scheme applied only to land areas and has since been evolving in the light of experience. Although not yet formally approved by all the governments concerned, it is working effectively by voluntary agreement. Different approaches are necessary for conservation of Southern Ocean resources, especially krill. A start has been made with the ‘ Convention for the Conservation of Antarctic Seals’, 1972. There are many outstanding problems: all require effective cooperation between scientific and legal advisers, diplomats and politicians. Mention is made of recent British conservation legislation for South Georgia, the Falkland Islands and the Tristan da Cunha group. Some of the next steps are outlined.

Movements of southern elephant seals

1996 ◽  
Vol 74 (8) ◽  
pp. 1485-1496 ◽  
Author(s):  
B. J. McConnell ◽  
M. A. Fedak
Keyword(s):  
Southern Ocean ◽  
Continental Shelf ◽  
Antarctic Peninsula ◽  
Average Rate ◽  
Stationary Phases ◽  
Mirounga Leonina ◽  
Elephant Seals ◽  
South Georgia ◽  
Southern Elephant Seals ◽  
The Antarctic

Twelve southern elephant seals (Mirounga leonina) were tracked for an average of 119 days as they left their breeding or moulting beaches on the island of South Georgia between 1990 and 1994. Females travelled either eastward up to 3000 km away to the open Southern Ocean or to the continental shelf on or near the Antarctic Peninsula. Males either stayed close to South Georgia or used South Georgia as a base for shorter trips. The females all left South Georgia in a directed manner at an average rate of 79.4 km/day over at least the first 15 days. Thereafter travel was interrupted by bouts of slower travel or stationary phases. The latter were localized at sites on the continental shelf or along its edge. Three seals that were tracked over more than one season repeated their outward direction of travel and used some of the same sites in subsequent years. The magnitude of the movements makes most of the Southern Ocean potentially available to elephant seals.

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