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1.
PLoS One ; 14(10): e0224249, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31648244

RESUMO

Natural history collections are fundamental for biodiversity research as well as for any applied environment-related research. These collections can be seen as archives of earth´s life providing the basis to address highly relevant scientific questions such as how biodiversity changes in certain environments, either through evolutionary processes in a geological timescale, or by man-made transformation of habitats throughout the last decades and/or centuries. A prominent example is the decline of the European flat oyster Ostrea edulis Linneaus, 1758 in the North Sea and the concomitant invasion of the common limpet slipper Crepidula fornicata, which has been implicated to have negative effects on O. edulis. We used collections to analyse population changes in both species in the North Sea. In order to reconstruct the change in distribution and diversity over the past 200 years, we combined the temporal and spatial information recorded with the collected specimens contained in several European natural history collections. Our data recover the decline of O. edulis in the North Sea from the 19th century to the present and the process of invasion of C. fornicata. Importantly, the decline of O. edulis was nearly completed before C. fornicata appeared in the North Sea, suggesting that the latter had nothing to do with the local extinction of O. edulis in the North Sea.

2.
Sci Rep ; 9(1): 9303, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31243329

RESUMO

Global scale analyses have recently revealed that the latitudinal gradient in marine species richness is bimodal, peaking at low-mid latitudes but with a dip at the equator; and that marine species richness decreases with depth in many taxa. However, these overall and independently studied patterns may conceal regional differences that help support or qualify the causes in these gradients. Here, we analysed both latitudinal and depth gradients of species richness in the NW Pacific and its adjacent Arctic Ocean. We analysed 324,916 distribution records of 17,414 species from 0 to 10,900 m depth, latitude 0 to 90°N, and longitude 100 to 180°N. Species richness per c. 50 000 km2 hexagonal cells was calculated as alpha (local average), gamma (regional total) and ES50 (estimated species for 50 records) per latitudinal band and depth interval. We found that average ES50 and gamma species richness decreased per 5° latitudinal bands and 100 m depth intervals. However, average ES50 per hexagon showed that the highest species richness peaked around depth 2,000 m where the highest total number of species recorded. Most (83%) species occurred in shallow depths (0 to 500 m). The area around Bohol Island in the Philippines had the highest alpha species richness (more than 8,000 species per 50,000 km2). Both alpha and gamma diversity trends increased from the equator to latitude 10°N, then further decreased, but reached another peak at higher latitudes. The latitudes 60-70°N had the lowest gamma and alpha diversity where there is almost no ocean in our study area. Model selection on Generalized Additive Models (GAMs) showed that the combined effects of all environmental predictors produced the best model driving species richness in both shallow and deep sea. The results thus support recent hypotheses that biodiversity, while highest in the tropics and coastal depths, is decreasing at the equator and decreases with depth below ~2000 m. While we do find the declines of species richness with latitude and depth that reflect temperature gradients, local scale richness proved poorly correlated with many environmental variables. This demonstrates that while regional scale patterns in species richness may be related to temperature, that local scale richness depends on a greater variety of variables.

3.
Sci Rep ; 9(1): 9260, 2019 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-31239511

RESUMO

Laonice Malmgren, 1867 (Annelida: Spionidae) is a common polychaete genus in the deep-sea. Although most species are quite well studied morphologically, fragmentation and other damage that occurs during sampling often hampers morphological species identification of deep-sea specimens. In this study, we employ three molecular markers (16S, COI and 18S) to study the biodiversity and the distribution patterns of Laonice from the tropical North Atlantic and the Puerto Rico Trench. Based upon different molecular analyses (Automated Barcode Gap Discovery, pairwise genetic distances, phylogenetics, haplotype networks) we were able to identify and differentiate eight Laonice species. Up to four of these species co-occurred sympatrically at the same station. The majority of species were found at multiple stations and two species in the eastern as well as western Atlantic had ranges of up to 4,000 km. Genetic differentiation across these extensive geographic distances was very low. Surprisingly, one 16S haplotype was shared between individuals 2,776 km apart and individuals from the Caribbean and the abyssal plain in the eastern Atlantic (>3,389 km) differed in only a single mutation in 16S. Our results suggest that members of this genus successfully disperse across large geographic distances and are largely unaffected by topographic barriers.

4.
Proc Biol Sci ; 285(1884)2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30068675

RESUMO

An understanding of the balance of interspecific competition and the physical environment in structuring organismal communities is crucial because those communities structured primarily by their physical environment typically exhibit greater sensitivity to environmental change than those structured predominantly by competitive interactions. Here, using detailed phylogenetic and functional information, we investigate this question in macrofaunal assemblages from Northwest Atlantic Ocean continental slopes, a high seas region projected to experience substantial environmental change through the current century. We demonstrate assemblages to be both phylogenetically and functionally under-dispersed, and thus conclude that the physical environment, not competition, may dominate in structuring deep-ocean communities. Further, we find temperature and bottom trawling intensity to be among the environmental factors significantly related to assemblage diversity. These results hint that deep-ocean communities are highly sensitive to their physical environment and vulnerable to environmental perturbation, including by direct disturbance through fishing, and indirectly through the changes brought about by climate change.


Assuntos
Organismos Aquáticos , Ecossistema , Pesqueiros , Animais , Oceano Atlântico , Mudança Climática , Filogenia , Temperatura
5.
Glob Chang Biol ; 24(10): 4667-4681, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29999582

RESUMO

How the abundant pelagic life of the Southern Ocean survives winter darkness, when the sea is covered by pack ice and phytoplankton production is nearly zero, is poorly understood. Ice-associated ("sympagic") microalgae could serve as a high-quality carbon source during winter, but their significance in the food web is so far unquantified. To better understand the importance of ice algae-produced carbon for the overwintering of Antarctic organisms, we investigated fatty acid (FA) and stable isotope compositions of 10 zooplankton species, and their potential sympagic and pelagic carbon sources. FA-specific carbon stable isotope compositions were used in stable isotope mixing models to quantify the contribution of ice algae-produced carbon (αIce ) to the body carbon of each species. Mean αIce estimates ranged from 4% to 67%, with large variations between species and depending on the FA used for the modelling. Integrating the αIce estimates from all models, the sympagic amphipod Eusirus laticarpus was the most dependent on ice algal carbon (αIce : 54%-67%), and the salp Salpa thompsoni showed the least dependency on ice algal carbon (αIce : 8%-40%). Differences in αIce estimates between FAs associated with short-term vs. long-term lipid pools suggested an increasing importance of ice algal carbon for many species as the winter season progressed. In the abundant winter-active copepod Calanus propinquus, mean αIce reached more than 50% in late winter. The trophic carbon flux from ice algae into this copepod was between 3 and 5 mg C m-2  day-1 . This indicates that copepods and other ice-dependent zooplankton species transfer significant amounts of carbon from ice algae into the pelagic system, where it fuels the food web, the biological carbon pump and elemental cycling. Understanding the role of ice algae-produced carbon in these processes will be the key to predictions of the impact of future sea ice decline on Antarctic ecosystem functioning.


Assuntos
Carbono/metabolismo , Ecossistema , Camada de Gelo , Fitoplâncton/metabolismo , Estações do Ano , Zooplâncton/metabolismo , Animais , Regiões Antárticas , Ciclo do Carbono , Isótopos de Carbono , Ácidos Graxos/metabolismo , Cadeia Alimentar
6.
PeerJ ; 6: e4887, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29892501

RESUMO

The bathyal to hadal deep sea of north-west Pacific Ocean was recently intensively sampled during four international expeditions (KuramBio I and II, SoJaBio and SokhoBio). A large amphipod, Rhachotropis saskia n. sp., was sampled in the Kuril-Kamchatka Trench and increases the number of described hadal species of that area to eight. A detailed description of the new species is provided, including illustrations, scanning-microscope images and molecular analysis. This predatory species was sampled at both continental and ocean abyssal margins of the Kuril-Kamchatka Trench as well as at hadal depths of the trench. The wide bathymetric distribution of the new species over more than 3,000 m is confirmed by molecular analysis, indicating that the Kuril Kamchatka Trench is not a distribution barrier for this species. However, the molecular analysis indicated the presence of isolation by distance of the populations of the studied taxon.

7.
Zootaxa ; 4139(3): 391-418, 2016 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-27470810

RESUMO

Ostracods have an extensive fossil record and are widely applied in palaeoenvironmental reconstructions. Here, we investigate the biogeography of two common and widespread genera, Abyssocythere and Dutoitella. Both appeared in the Cretaceous and are widely distributed in modern deep seas, but all species are restricted in distribution. The earliest record of Dutoitella is from shallow water, while the earliest Abyssocythere is from the deep sea. The Southern Ocean/Southern Atlantic seem to have been the area where both genera originated, and from which they eventually colonised other oceans. Dutoitella diversified into at least eleven species during Campanian-Eocene times, and by the end of the Eocene, the genus had spread to the Indian Ocean. This pattern continued after the establishment of the psychrosphere into the Neogene, with the development of numerous Miocene species. Abyssocythere, with 15 species, while also diversifying in the late Cretaceous South Atlantic, appears to have developed fewer species than Dutoitella. Finally, we describe three new species from the Southern Ocean (Abyssocythere bensoni sp. nov., Dutoitella karanovicae sp. nov. and Dutoitella richarddinglei  sp. nov.), re-illustrate the types of Abyssocythere squalidentata (Brady, 1880) and Dutoitella suhmi (Brady, 1880), and study the soft parts of the genus Dutoitella, which were previously undocumented.


Assuntos
Crustáceos/anatomia & histologia , Crustáceos/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Oceano Atlântico , Tamanho Corporal , Crustáceos/crescimento & desenvolvimento , Ecossistema , Fósseis/anatomia & histologia , Geografia , Oceano Índico , Masculino , Tamanho do Órgão
8.
PLoS One ; 9(7): e100551, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25032993

RESUMO

An international effort is underway to establish a representative system of marine protected areas (MPAs) in the Southern Ocean to help provide for the long-term conservation of marine biodiversity in the region. Important to this undertaking is knowledge of the distribution of benthic assemblages. Here, our aim is to identify the areas where benthic marine assemblages are likely to differ from each other in the Southern Ocean including near-shore Antarctica. We achieve this by using a hierarchical spatial classification of ecoregions, bathomes and environmental types. Ecoregions are defined according to available data on biogeographic patterns and environmental drivers on dispersal. Bathomes are identified according to depth strata defined by species distributions. Environmental types are uniquely classified according to the geomorphic features found within the bathomes in each ecoregion. We identified 23 ecoregions and nine bathomes. From a set of 28 types of geomorphic features of the seabed, 562 unique environmental types were classified for the Southern Ocean. We applied the environmental types as surrogates of different assemblages of biodiversity to assess the representativeness of existing MPAs. We found that 12 ecoregions are not represented in MPAs and that no ecoregion has their full range of environmental types represented in MPAs. Current MPA planning processes, if implemented, will substantially increase the representation of environmental types particularly within 8 ecoregions. To meet internationally agreed conservation goals, additional MPAs will be needed. To assist with this process, we identified 107 spatially restricted environmental types, which should be considered for inclusion in future MPAs. Detailed supplementary data including a spatial dataset are provided.


Assuntos
Organismos Aquáticos/classificação , Conservação dos Recursos Naturais , Monitoramento Ambiental , Biologia Marinha , Animais , Regiões Antárticas , Organismos Aquáticos/genética , Biodiversidade , Sedimentos Geológicos/análise , Camada de Gelo , Oceanos e Mares
9.
Proc Natl Acad Sci U S A ; 111(23): 8524-9, 2014 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-24912168

RESUMO

Explaining patterns of commonness and rarity is fundamental for understanding and managing biodiversity. Consequently, a key test of biodiversity theory has been how well ecological models reproduce empirical distributions of species abundances. However, ecological models with very different assumptions can predict similar species abundance distributions, whereas models with similar assumptions may generate very different predictions. This complicates inferring processes driving community structure from model fits to data. Here, we use an approximation that captures common features of "neutral" biodiversity models--which assume ecological equivalence of species--to test whether neutrality is consistent with patterns of commonness and rarity in the marine biosphere. We do this by analyzing 1,185 species abundance distributions from 14 marine ecosystems ranging from intertidal habitats to abyssal depths, and from the tropics to polar regions. Neutrality performs substantially worse than a classical nonneutral alternative: empirical data consistently show greater heterogeneity of species abundances than expected under neutrality. Poor performance of neutral theory is driven by its consistent inability to capture the dominance of the communities' most-abundant species. Previous tests showing poor performance of a neutral model for a particular system often have been followed by controversy about whether an alternative formulation of neutral theory could explain the data after all. However, our approach focuses on common features of neutral models, revealing discrepancies with a broad range of empirical abundance distributions. These findings highlight the need for biodiversity theory in which ecological differences among species, such as niche differences and demographic trade-offs, play a central role.


Assuntos
Algoritmos , Biodiversidade , Biologia Marinha/métodos , Modelos Biológicos , Clima Frio , Geografia , Densidade Demográfica , Dinâmica Populacional , Especificidade da Espécie , Clima Tropical
10.
Glob Chang Biol ; 20(10): 3004-25, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24802817

RESUMO

Antarctic and Southern Ocean (ASO) marine ecosystems have been changing for at least the last 30 years, including in response to increasing ocean temperatures and changes in the extent and seasonality of sea ice; the magnitude and direction of these changes differ between regions around Antarctica that could see populations of the same species changing differently in different regions. This article reviews current and expected changes in ASO physical habitats in response to climate change. It then reviews how these changes may impact the autecology of marine biota of this polar region: microbes, zooplankton, salps, Antarctic krill, fish, cephalopods, marine mammals, seabirds, and benthos. The general prognosis for ASO marine habitats is for an overall warming and freshening, strengthening of westerly winds, with a potential pole-ward movement of those winds and the frontal systems, and an increase in ocean eddy activity. Many habitat parameters will have regionally specific changes, particularly relating to sea ice characteristics and seasonal dynamics. Lower trophic levels are expected to move south as the ocean conditions in which they are currently found move pole-ward. For Antarctic krill and finfish, the latitudinal breadth of their range will depend on their tolerance of warming oceans and changes to productivity. Ocean acidification is a concern not only for calcifying organisms but also for crustaceans such as Antarctic krill; it is also likely to be the most important change in benthic habitats over the coming century. For marine mammals and birds, the expected changes primarily relate to their flexibility in moving to alternative locations for food and the energetic cost of longer or more complex foraging trips for those that are bound to breeding colonies. Few species are sufficiently well studied to make comprehensive species-specific vulnerability assessments possible. Priorities for future work are discussed.


Assuntos
Organismos Aquáticos , Mudança Climática , Camada de Gelo , Regiões Antárticas , Biota , Ecossistema , Oceanos e Mares , Movimentos da Água , Vento
11.
Zootaxa ; 3786: 1-43, 2014 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-24869520

RESUMO

In the benthic samples collected during the deep-sea expeditions ANDEEP from the Weddell Sea and DIVA from the Argentine Basin the isopod family Munnopsidae was the most specious and numerous. Among the collected munnopsids three new species of Tytthocope Wilson & Hessler, 1981 have been discovered. Tytthocope is one of six genera of the subfamily Eurycopinae. It differs from other genera of the Eurycopinae by having a strongly reduced pereonite 7 and inflated pleotelson. Until now the genus consisted of five described species: four of them are known from the northern Atlantic and only one species, T. sulcifrons (Barnard, 1920) was described from the southern Atlantic off the South Africa coast. The five known species of Tytthocope have been recorded from depths less than 1461 m. Descriptions of three new species of Tytthocope collected in the South Atlantic and Southern Ocean at depths between 1530-4608 m, T. divae sp. nov., T. fahrbachi sp. nov. and T. longitelson sp. nov. are presented in the paper. T. sulcifrons is redescribed herein based on the type material.


Assuntos
Isópodes/anatomia & histologia , Isópodes/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Feminino , Isópodes/crescimento & desenvolvimento , Masculino , Oceanos e Mares
12.
PLoS One ; 9(3): e93018, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24663246

RESUMO

The skeleton of a natural whale fall discovered in the Southern Ocean at 1,445 m was densely covered by one small, janirid isopod. Jaera tyleri sp. nov. is the first of its genus found in the southern hemisphere and in the deep sea and is described herein. Morphological and molecular investigations revealed the systematic position of this species new to science. Phylogenetic analysis of the 18S locus confirms that this species falls in a strongly supported monophyletic clade of Jaera species. The whale bone habitat of J. tyleri sp. nov. is quite different from those of other species of the genus Jaera. The analysis of bathymetric and distribution patterns of the Janiridae in general and Jaera specifically confirm the unusualness of the habitat for this isopod species. The abundance of J. tyleri sp. nov. on the whale bones and its absence from other nearby habitats suggests it to be a whale-fall specialist. The analysis of the size-frequency distributions of J. tyleri sp. nov. suggests multimodal population structure with continuous breeding activity throughout the year. The fecundity of the species is low but in line with reduced fecundity observed in polar and small-sized isopods.


Assuntos
Osso e Ossos , Loci Gênicos , Isópodes , Filogenia , RNA Ribossômico 18S/genética , Baleias , Animais , Isópodes/classificação , Isópodes/genética
13.
Zootaxa ; 3692: 1-258, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-26146684

RESUMO

The richness of life in parts of the earth that to us appear inhospitable and remote never fails to fascinate scientists and non-scientists alike. The largest ecosystem of the planet, the abyssal plains of the world ocean, makes up about 90 percent of the seafloor and thus nearly 78 percent of the Earth's surface, yet only a minor fraction of this huge environment has been investigated. Authors have questioned repeatedly "how many species would live on earth and in the ocean" (Mora et al. 2011; May 2011), and recent estimations predict ~ 8.7 million (+/- 1.3 million SE) eukaryotic species globally, with 2.2 million of these being marine (Mora et al. 2011). To date, 91 % of all marine species still await description. Other authors concluded that marine biodiversity is grossly underestimated (Bouchet 2006) because so far, only one-third of all species descriptions concerns marine biota (Reaka-Kudla 1997; Groombridge & Jenkins 2000, Grassle 2001, Boltovskoy et al. 2005). We know that marine live thrives even in hadal trenches (Jamieson et al. 2009), that biogeographic ranges in the deep sea are dynamic (McClain & Mincks Hardy 2010) and that the origin of the modern deep-sea fauna is ancient (Thuy et al. 2012). For example, the origin of Isopoda dates back to Permo-Triassic times (232­ 314 mya; Lins et al. 2012).


Assuntos
Distribuição Animal/fisiologia , Biodiversidade , Invertebrados/anatomia & histologia , Invertebrados/classificação , Animais , Regiões Antárticas , Feminino , Invertebrados/fisiologia , Masculino , Especificidade da Espécie
14.
Zootaxa ; 3670: 339-48, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-26438944

RESUMO

During the Victoria-Land Transect project two specimens of a new species, Fissarcturus walteri sp. nov., were found in the Ross Sea along the Victoria Land Coast, Antarctica, during the 19th Italica expedition in February 2004. This is the second species of Fissarcturus from the Ross Sea after F. rossi Brandt, 2007. F. walteri sp. nov. is most similar to Fissarcturus granulosus (Nordenstam, 1933) from South Georgia but can be distinguished by the blunt short, anteriorly directed supraocular spines and elevations and some other characters as described herewith.


Assuntos
Isópodes/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Isópodes/anatomia & histologia , Isópodes/crescimento & desenvolvimento , Masculino , Oceanos e Mares , Tamanho do Órgão
15.
Ecol Evol ; 2(2): 453-85, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22423336

RESUMO

Because of the unique conditions that exist around the Antarctic continent, Southern Ocean (SO) ecosystems are very susceptible to the growing impact of global climate change and other anthropogenic influences. Consequently, there is an urgent need to understand how SO marine life will cope with expected future changes in the environment. Studies of Antarctic organisms have shown that individual species and higher taxa display different degrees of sensitivity to environmental shifts, making it difficult to predict overall community or ecosystem responses. This emphasizes the need for an improved understanding of the Antarctic benthic ecosystem response to global climate change using a multitaxon approach with consideration of different levels of biological organization. Here, we provide a synthesis of the ability of five important Antarctic benthic taxa (Foraminifera, Nematoda, Amphipoda, Isopoda, and Echinoidea) to cope with changes in the environment (temperature, pH, ice cover, ice scouring, food quantity, and quality) that are linked to climatic changes. Responses from individual to the taxon-specific community level to these drivers will vary with taxon but will include local species extinctions, invasions of warmer-water species, shifts in diversity, dominance, and trophic group composition, all with likely consequences for ecosystem functioning. Limitations in our current knowledge and understanding of climate change effects on the different levels are discussed.

16.
Zookeys ; (144): 1-19, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22207784

RESUMO

Dubinectes infirmussp. n., Munnopsidae, is described from the Argentine Basin, southwest Atlantic, at depths between 4586-4607 m. The new species is distinguished by a narrow rim of the pleotelson posterior margin which is not raising over its dorsal surface; article 3 of the antennula is subequal in length to article 2; distomedial lobes of male pleopod 1 are of same size as distolateral lobes; stylet of male pleopod 2 is subequal in length to protopod; uropod exopod is more than a half of endopod length. Some generic characters which are weakly pronounced in the new species or have different state are defined more precisely in the revised diagnosis of Dubinectes. The modified diagnosis of the genus, a key to the species of Dubinectes as well as the distribution of the genus are presented.

17.
Zookeys ; (82): 45-57, 2011 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-21594056

RESUMO

A new species of Coulmannia, Coulmannia rossensis, is described from the Ross Sea, Antarctica. It is most similar to Coulmannia ramosae Castelló, 2004, but can easily be distinguished from this species bythe males yielding a pair of granulate humps on the dorsum of the pereonites 1-6 and a single granulate hump on the pereonite 7 and the free pleonite. Coulmannia rossensissp. n. is sexually dimorphic. The dorsal sculpture of the female bodies yield a single granulate hump on all the pereonites and free pleonite. The species of the genus Coulmannia are restricted to the Southern Ocean, and Coulmannia rossensissp. n. is the fourth species included in it.

18.
Zookeys ; (57): 9-49, 2010 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-21594187

RESUMO

Descriptions of Macrostylis antennamagnasp. n. and Macrostylis uniformissp. n. are presented with notes on intraspecific variability and sexual dimorphism. Macrostylis uniformissp. n. showes differences to Macrostylis antennamagnasp. n. in the length of the antenna 2, the shape of the pleotelson and length of uropods.The genus Desmostylis Brandt, 1992 (formerly including the two species Desmostylis obscurus Brandt, 1992 and Desmostylis gerdesi Brandt, 2002) is synonymised with the genus Macrostylis. Based on type material additional remarks and additions to the original descriptions are provided for both species. Results lead to following nomenclatorial changes: Macrostylis obscurus (Brandt, 1992), comb. n. and Macrostylis gerdesi (Brandt, 2002), comb. n. A setal nomenclature is proposed and the diagnosis for the family is revised.

19.
Curr Biol ; 18(23): R1104-6, 2008 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-19081047

RESUMO

Deep seas cover more than half the planet and depend due to their lack of light on inflow of nutrients from above. Viruses play a critical role for the trophic supply of the deep-sea environments.


Assuntos
Bactérias , Ecossistema , Cadeia Alimentar , Invertebrados/crescimento & desenvolvimento , Água do Mar , Animais , Bactérias/crescimento & desenvolvimento , Bactérias/virologia , Biodiversidade , Biomassa , Sedimentos Geológicos/microbiologia , Sedimentos Geológicos/virologia , Lisogenia , Biologia Marinha , Compostos Orgânicos/metabolismo , Água do Mar/microbiologia , Água do Mar/virologia
20.
Nature ; 447(7142): 307-11, 2007 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-17507981

RESUMO

Shallow marine benthic communities around Antarctica show high levels of endemism, gigantism, slow growth, longevity and late maturity, as well as adaptive radiations that have generated considerable biodiversity in some taxa. The deeper parts of the Southern Ocean exhibit some unique environmental features, including a very deep continental shelf and a weakly stratified water column, and are the source for much of the deep water in the world ocean. These features suggest that deep-sea faunas around the Antarctic may be related both to adjacent shelf communities and to those in other oceans. Unlike shallow-water Antarctic benthic communities, however, little is known about life in this vast deep-sea region. Here, we report new data from recent sampling expeditions in the deep Weddell Sea and adjacent areas (748-6,348 m water depth) that reveal high levels of new biodiversity; for example, 674 isopods species, of which 585 were new to science. Bathymetric and biogeographic trends varied between taxa. In groups such as the isopods and polychaetes, slope assemblages included species that have invaded from the shelf. In other taxa, the shelf and slope assemblages were more distinct. Abyssal faunas tended to have stronger links to other oceans, particularly the Atlantic, but mainly in taxa with good dispersal capabilities, such as the Foraminifera. The isopods, ostracods and nematodes, which are poor dispersers, include many species currently known only from the Southern Ocean. Our findings challenge suggestions that deep-sea diversity is depressed in the Southern Ocean and provide a basis for exploring the evolutionary significance of the varied biogeographic patterns observed in this remote environment.


Assuntos
Biodiversidade , Geografia , Água do Mar , Animais , Regiões Antárticas , Invertebrados/classificação , Invertebrados/fisiologia , Biologia Marinha , Oceanos e Mares , Filogenia
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