Benthic hydroids (Cnidaria, Hydrozoa) from the Weddell Sea (Antarctica)

Zootaxa ◽  
2019 ◽  
Vol 4570 (1) ◽  
pp. 1
Author(s):  
JOAN J. SOTO ÀNGEL ◽  
ÁLVARO L. PEÑA CANTERO
Keyword(s):  
Southern Ocean ◽  
New Records ◽  
Weddell Sea ◽  
Reproductive Phenology ◽  
Antarctic Region ◽  
Bathymetric Range ◽  
Eastern Sector ◽  
Number Of Species ◽  
The Antarctic

Hydrozoans are a conspicuous component of Antarctic benthic communitites. Recent taxonomic effort has led to a substantial increase in knowledge on the diversity of benthic hydroids from some areas of the Southern Ocean, including the Weddell Sea, the largest sea in the Antarctic region. However, the study of many hydrozoan taxa are still pending, and the diversity in this huge region is expected to be higher than currently known. In order to contribute to the knowledge of taxonomy, ecology and distribution of these cnidarians, a study of unpublished material collected by several German Antarctic expeditions aboard the RV Polarstern in the eastern sector of the Weddell Sea has been conducted. A total of 77 species belonging to 22 families and 28 genera of benthic hydroids have been inventoried, constituting the most prolific collection hitherto analyzed. Most species (81%) belong to Leptothecata, but the observed share of Anthoathecata (19%) is higher than in previous Antarctic hydrozoan studies. Symplectoscyphidae was the most speciose family with 16 representatives (22%), followed by Haleciidae with 10 (14%) and Staurothecidae with 8 (11%). The number of species known in the area was increased with 27 new records, including several species rarely documented. As a result, the Weddell Sea becomes the second Antarctic region in terms of hydrozoan diversity, with 89 species known to date. Novel data on the use of substrate, reproductive phenology, and bathymetric range are provided for the inventoried species. 

Molecular systematics of Thouarella (Octocorallia:Primnoidae) with the description of three new species from the Southern Ocean based on combined molecular and morphological evidence

2021 ◽  
Author(s):  
Mónica Núñez-Flores ◽  
Daniel Gomez-Uchida ◽  
Pablo J. López-González
Keyword(s):  
New Species ◽  
Southern Ocean ◽  
Species Delimitation ◽  
Nuclear Dna ◽  
Phylogenetic Analyses ◽  
Weddell Sea ◽  
Morphological Evidence ◽  
Three New Species ◽  
Taxonomic Framework ◽  
The Antarctic

Thouarella Gray, 1870, is one of the most speciose genera among gorgonians of the family Primnoidae (Cnidaria:Octocorallia:Anthozoa), being remarkably diverse in the Antarctic and sub-Antarctic seafloor. However, their diversity in the Southern Ocean is likely underestimated. Phylogenetic analyses of mitochondrial and nuclear DNA markers were integrated with species delimitation approaches as well as morphological colonial and polyps features and skeletal SEM examinations to describe and illustrate three new species within Thouarella, from the Weddell Sea, Southern Ocean: T. amundseni sp. nov., T. dolichoespinosa sp. nov. and T. pseudoislai sp. nov. Our species delimitation results suggest, for the first time, the potential presence of Antarctic and sub-Antarctic cryptic species of primnoids, based on the likely presence of sibling species within T. undulata and T. crenelata. With the three new species here described, the global diversity of Thouarella has increased to 41 species, 15 of which are endemic to the Antarctic and sub-Antarctic waters. Consequently, our results provide new steps for uncovering the shelf benthonic macrofauna’s hidden diversity in the Southern Ocean. Finally, we recommend using an integrative taxonomic framework in this group of organisms and species delimitation approaches because the distinctions between some Thouarella species based only on a superficial examination of their macro- and micromorphological features is, in many cases, limited.

scholarly journals New records of isopod species of the Antarctic Specially Managed Area No. 1, Admiralty Bay, South Shetland Islands

2017 ◽  
Vol 38 (3) ◽  
pp. 409-419
Author(s):  
Karol Zemko ◽  
Krzysztof Pabis ◽  
Jacek Siciński ◽  
Magdalena Błażewicz
Keyword(s):  
Southern Ocean ◽  
New Records ◽  
South Shetland Islands ◽  
Small Scale ◽  
King George Island ◽  
Admiralty Bay ◽  
Shetland Islands ◽  
The Antarctic ◽  
First Time ◽  
Marine Basins

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).

An account of the Mysidacea (Crustacea, Malacostraca) of the Southern Ocean

1998 ◽  
Vol 10 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Angelika Brandt ◽  
Ute Mühlenhardt-Siegel ◽  
Volker Siegel
Keyword(s):  
Southern Ocean ◽  
Present State ◽  
Distribution Patterns ◽  
Taxonomic Diversity ◽  
Shelf Break ◽  
Bathymetric Distribution ◽  
Antarctic Region ◽  
Magellan Region ◽  
Antarctic Shelf ◽  
The Antarctic

An inventory of Antarctic and Subantarctic mysid fauna is presented, together with a summary of the present state of knowledge of species and their taxonomic diversity, geographic and bathymetric distribution patterns. Fifty nine species of Mysidacea (Crustacea, Peracarida) are now known. Of these, 37 were reported for the Antarctic region and 31 for the Magellan region; six species occur further north in the Southern Ocean, but south of 40°S. 51% of the Antarctic Mysidacea are endemic, and the figure for the Magellan region is 48%. Most of the species live hyperbenthically, but some also occur bathy- or mesopelagically. Mysidetes has the most species in the Southern Ocean, and Eucopia australis is the species with the widest bathymetric distribution (600–6000 m depth). It is concluded that an emergence of species onto the Antarctic shelf in the Neogene was quite unlikely, because none of the mysid species is a true deepsea species, and most species occur on the shelf or at the shelf break. It is more probable that present day species colonized the Southern Ocean via shallower waters. The examples of the distribution of different genera suggest that the Mysidacea of the Southern Ocean probably had various geographical origins.

A new species and new records of Lecanora (Lecanoraceae, lichenized Ascomycota) with usnic acid from the Antarctic region

Phytotaxa ◽  
2016 ◽  
Vol 261 (2) ◽  
pp. 185 ◽  
Author(s):  
IRIS NADIA DE LA ROSA ◽  
ALFREDO PASSO ◽  
JUAN MANUEL RODRÍGUEZ ◽  
JORGE OSCAR CHIAPELLA ◽  
MARÍA INÉS MESSUTI
Keyword(s):  
New Species ◽  
Secondary Metabolite ◽  
Antarctic Peninsula ◽  
New Records ◽  
Usnic Acid ◽  
Distribution Range ◽  
Antarctic Region ◽  
The Antarctic ◽  
First Time ◽  
A New Species

A new species of Lecanora, L. flavocrassa, is described from the Antarctic region. Additionally, L. stenotropa is registered for the first time from Antarctica and the distribution range of L. intricata is extended to the Antarctic Peninsula. A key to the species of Lecanora from Antarctica that contain usnic acid as secondary metabolite is presented.

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 Orange is the new white: taxonomic revision of Antarctic Tritonia species (Gastropoda: Nudibranchia)

2020 ◽  
Author(s):  
Maria Eleonora Rossi ◽  
Conxita Avila ◽  
Juan Moles
Keyword(s):  
Southern Ocean ◽  
Phylogenetic Analyses ◽  
Taxonomic Revision ◽  
Molecular Data ◽  
Molecular Techniques ◽  
Weddell Sea ◽  
Valid Species ◽  
Phylogenetic Position ◽  
Antarctic Species ◽  
The Antarctic

ABSTRACTAmong nudibranch molluscs, the family Tritoniidae gathers taxa with unclear phylogenetic position, such as some species of the genus Tritonia Cuvier, 1798. Currently, 35 valid species belong to this genus and only three of them are found in the Southern Ocean, namely T. challengeriana Bergh, 1884, T. dantarti Ballesteros & Avila, 2006, and T. vorax (Odhner, 1926). In this study, we shed light on the long-term discussed systematics and taxonomy of Antarctic Tritonia species using morpho-anatomical and molecular techniques. Samples from the Weddell Sea and Bouvet Island were dissected and prepared for scanning electron microscopy. The three molecular markers COI, 16S, and H3 were sequenced and analysed through maximum likelihood and Bayesian methods. The phylogenetic analyses and species delimitation tests clearly distinguished two species, T. challengeriana and T. dantarti, being widely-spread in the Southern Ocean, and endemic to Bouvet Island, respectively. Coloration seemed to be an unreliable character to differentiate among species since molecular data revealed both species can either have orange or white colour-morphotypes. This variability could be explained by pigment sequestration from the soft coral species they feed on. Morphological analyses reveal differences between Antarctic and Magellanic specimens of T. challengeriana, thus, we suggest the resurrection of T. antarctica Martens & Pfeffer, 1886 to encompass exclusively the Antarctic species. To progress further, additional molecular data from Magellanic specimens are required to definitely resolve their taxonomy and systematics.

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).

Paleogene Polar Plankton and export productivity changes between the Eocene and Oligocene

2020 ◽  
Author(s):  
Gabrielle Rodrigues de Faria ◽  
David Lazarus ◽  
Ulrich Struck ◽  
Gayane Asatryan ◽  
Johan Renaudie ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Carbon Isotope ◽  
Ocean Circulation ◽  
Deep Sea ◽  
Fine Fraction ◽  
Weddell Sea ◽  
Oxygen And Carbon Isotope ◽  
The Antarctic ◽  
The Impact ◽  
Export Productivity

<p>Aiming to support the prediction of future climate developments, this project investigates the role on geological timescale of the ocean plankton in reducing atmospheric carbon concentration by exporting carbon to the deep-sea. While it is well-known that the transition from the Eocene to the Oligocene brought significant climate changes and, in connection, also a change of the oceans’ carbon export production, the important role of phytoplankton and the links to changing ocean circulation are still poorly understood, as is, similarly, the impact on those changes on the diversity of the plankton contributing to the carbon pump. Investigating the nature of this interaction will provide significant insight into the functions of the oceans as climate regulators.</p><p>To address those question, we are generating diversity and absolute abundance data for diatoms and radiolarians, biogeographic data for radiolarians, as well as oxygen and carbon isotope data on planktic and benthic foraminifera, and on the fine fraction (<45µm, i. e. coccoliths), as well as other proxies to estimate surface and deep ocean temperatures and export productivity. These will be generated as paired data from individual samples in various deep-sea drilling sites in and around the Southern Ocean (as it is the focal point of the climatic/oceanographic changes at that period). These data will then be compiled and confronted to an ocean circulation model.</p><p>Here we will present our results so far (oxygen and carbon isotope on the bulk fine fraction, as well as radiolarian and diatom diversity estimates), based on two main localities from the antarctic (ODP Site 689B from the Weddell Sea) and the subantarctic (ODP Site 1090B on the southern flank of the Agulhas ridge) South Atlantic. A comparison with a newly generated, database-driven diversity analysis of the same groups in the same region, using the Neptune (NSB) database, will also be shown. While the exhaustive taxonomical compilation made on these two sites for the diatoms records three times more species than what was recorded in the literature for the Southern Ocean biome, it still shows an evolutionary turnover at the Eocene-Oligocene, just as the classic, NSB-driven analysis does. The fine fraction oxygen isotope at both sites 689B and 1090B show a pattern similar to that recorded in planktonic foraminifera in neighbour sites, indicating a significant drop in SST close to the Eocene-Oligocene boundary, while the fine fraction carbon isotope signal in the antarctic site shows a subsequent decrease indicating changes in exported productivity 2Myr after the global cooling.</p>

scholarly journals A global compilation of dissolved iron measurements: focus on distributions and processes in the Southern Ocean

2012 ◽  
Vol 9 (6) ◽  
pp. 2333-2349 ◽  
Author(s):  
A. Tagliabue ◽  
T. Mtshali ◽  
O. Aumont ◽  
A. R. Bowie ◽  
M. B. Klunder ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Future Research ◽  
Ocean Water ◽  
Missing Measurements ◽  
Antarctic Region ◽  
Dissolved Iron ◽  
Limiting Nutrient ◽  
Modelling Studies ◽  
The Antarctic ◽  
Subantarctic Region

Abstract. Due to its importance as a limiting nutrient for phytoplankton growth in large regions of the world's oceans, ocean water column observations of concentration of the trace-metal iron (Fe) have increased markedly over recent decades. Here we compile >13 000 global measurements of dissolved Fe (dFe) and make this available to the community. We then conduct a synthesis study focussed on the Southern Ocean, where dFe plays a fundamental role in governing the carbon cycle, using four regions, six basins and five depth intervals as a framework. Our analysis highlights depth-dependent trends in the properties of dFe between different regions and basins. In general, surface dFe is highest in the Atlantic basin and the Antarctic region. While attributing drivers to these patterns is uncertain, inter-basin patterns in surface dFe might be linked to differing degrees of dFe inputs, while variability in biological consumption between regions covaries with the associated surface dFe differences. Opposite to the surface, dFe concentrations at depth are typically higher in the Indian basin and the Subantarctic region. The inter-region trends can be reconciled with similar ligand variability (although only from one cruise), and the inter-basin difference might be explained by differences in hydrothermal inputs suggested by modelling studies (Tagliabue et al., 2010) that await observational confirmation. We find that even in regions where many dFe measurements exist, the processes governing the seasonal evolution of dFe remain enigmatic, suggesting that, aside from broad Subantarctic – Antarctic trends, biological consumption might not be the major driver of dFe variability. This highlights the apparent importance of other processes such as exogenous inputs, physical transport/mixing or dFe recycling processes. Nevertheless, missing measurements during key seasonal transitions make it difficult to better quantify and understand surface water replenishment processes and the seasonal Fe cycle. Finally, we detail the degree of seasonal coverage by region, basin and depth. By synthesising prior measurements, we suggest a role for different processes and highlight key gaps in understanding, which we hope can help structure future research efforts in the Southern Ocean.

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