971 resultados para SE Brazilian continental shelf


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The present paper reports on 22 species collected by the Brazilian Program of Living Resources in the Exclusive Economic Zone (REVIZEE). A new genus and species of Cribrilinidae, Corbuliporina crepida n. gen. et sp., is described, along with seventeen other new species: Chaperia brasiliensis n. sp., Amastigia aviculifera n. sp., Isosecuriflustra pinniformis n. sp., Cellaria subtropicalis n. sp., Melicerita brasiliensis n. sp., Arachnopusia haywardi n. sp., Smittina migottoi n. sp., Hippomenella amaralae n. sp., Rogicka joannae n. sp., Malakosaria atlantica n. sp., Turbicellepora winstonae n. sp., Rhynchozoon coalitum n. sp., Stephanollona angusta n. sp., Stephanollona arborescens n. sp., Aulopocella americana n. sp., Conescharellina cookae n. sp. and Conescharellina bocki n. sp. Chorizopora brongniartii (Audouin, 1826) is recorded for the first time in Brazilian waters and a new combination for Rhynchozoon arborescens Canu & Bassler, 1928 is established. New illustrations and taxonomic remarks are included for two little-known species from Brazil, Rogicka scopae (Canu & Bassler, 1928) and Fenestrulina ampla Canu & Bassler, 1928. A compilation of species recorded from deeper waters of the Brazilian coast is included.

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A new genus and species of Normanellidae (Copepoda, Harpacticoida), Paranaiara inajae gen. et sp. nov., is described from the continental shelf off the northern coast of Sao Paulo State, Brazil. The new genus differs from the type genus Normanella Brady, 1880 and Sagamiella Lee & Huys, 1999 in its presence of lamelliform caudal rami, a maxillulary endopod represented by 2 setae, an unarmed maxillipedal syncoxa, and reduced setation on P2 enp-2 (without outer spine) and P3 enp-2 (with only 2 inner setae). All these apomorphic character states are shared with the genus Pseudocletodes Scott & Scott, 1893, formerly placed in the family Nannopodidae (ex Huntemanniidae) and here assigned to the Normanellidae. Pseudocletodes can be differentiated from Paranaiara by the loss of the P1 endopod and of the inner seta on P2-P4 enp-1, the presence of only 2 inner setae on P2 enp-2 (instead of 3) and only 1 inner seta on P4 exp-3 (instead of 2), the presence of a second inner seta on P4 enp-2 (instead of 1), the morphology of the fifth pair of legs which are not medially fused and have only 3 endopodal elements (instead of 4) in the male, and the well developed caudal ramus seta V (instead of rudimentary). It is postulated that prehensility of the P1 endopod was secondarily lost in the common ancestor of Paranaiara and Pseudocletodes. An updated family diagnosis of the Normanellidae and a dichotomous identification key to the 22 currently valid species are presented.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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This paper provides information on the morphology and occurrence of extant diatoms of the family Asterolampraceae and Azpeitia species of the southernmost Brazilian continental shelf and slope waters in the Southwestern Atlantic Ocean (28 - 34°S), under the influence of Tropical, Subtropical, Subantarctic Waters, terrestrial discharges from La Plata River and Lagoa dos Patos lagoon. Plankton was sampled (20 µm net; vertical hauls) at the same 27 stations in winter 2005 and summer 2007. Among Asterolampraceae, Asteromphalus flabellatus was the most frequent species (57% of samples) observed mainly in winter samples (92%) in Subtropical Shelf Water but also under the influence of La Plata River plume (salinity <35). Lower frequencies were observed for Asterolampra marylandica, Asteromphalus elegans, Asteromphalus heptactis and Spatangidium arachne. Four species of Azpeitia were observed: A. barronii and A. neocrenulata for the first time in the South Atlantic Ocean while A. africana and A. nodulifer had already been registered in equatorial and southern areas of Brazil. All Azpeitia species were rare (19%) in offshore samples (100-200 m depth. Remarks on the morphology based on light and scanning electron microcopy observations are provided along with their distribution in the study area.

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Fossils of terrestrial mammals preserved in submarine environment have been recorded in several places around the world. In Brazil such fossils are rather abundant in the southernmost portion of the coast, associated to fossiliferous concentrations at depths up to 10 m. Here is presented a review of such occurrences and the first record of fossils in deeper areas of the continental shelf. The fossils encompass several groups of both extinct and extant mammals, and exhibit several distinct taphonomic features, related to the marine environment. Those from the inner continental shelf are removed and transported from the submarine deposits to the coast during storm events, thus forming large konzentrat-lagerstatte on the beach, called "Concheiros". The only fossils from deeper zones of the shelf known so far are a portion of a skull, a left humerus and of a femur of Toxodon sp. and a lower right molar of a Stegomastodon waringi, all collected by fishermen at depths around 20 m. The presence of fossils at great depths and distances from the present coastline, without signs of abrasion and far from areas of fluvial discharges does indicate that these remains have not been transported from the continent to the shelf, but have been preserved directly on the area that today correspond to the continental shelf. These remains indicate the existence of large fossiliferous deposits that have developed during periods of sea-level lowstand (glacial maxima) and have been submerged and reworked by the sea-level rise at the end of the last glaciation. (C) 2010 Elsevier Ltd. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Sedimentological and benthic foraminifera analyses carried out on a core (length 4.15 in, collected at 22 degrees 56`31 `` S and 41 degrees 58`48 `` W, at a water depth of 43 in) sampled from the inner shelf of Cabo Frio, southeastern Brazilian continental margin, allowed identification of different hydrodynamic and productivity regimes related to sea-level fluctuations and/or climatic changes, during the last 9.4 ka cal BP. Prior to 7.0 ka cal BP, a less intense hydrodynamic and lower productivity regime occurred at lower sea levels and under drier climatic conditions. Between 7.0 and 5.0 ka cal BP, relatively stronger local oceanic circulation and relatively high productivity were observed, in a scenario of rising sea levels and more humid conditions. From 5.0 to 3.0 ka cal BP, bottom currents weakened and input of nutrients increased, with productivity levels similar to the previous phase at lower sea level and in a drier climate. From 3.0 ka cal BP up to the present, stronger hydrodynamic conditions and a higher productivity regime are linked to the establishment of the upwelling process in Cabo Frio. From 2.5 ka cal BP to the present, upwelling enhancement has been recognized, resulting from the combined action of NE winds and the intensification of the meandering pattern of the Brazil Current (BC). (C) 2008 Elsevier Ltd and INQUA. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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A total number of 4824 Mustelus schmitti was sampled. Females ranged from 25 to 93 em in spring and from 28 to 90 cm in summer. Males ranged from 34 to 82 and from 28 to 77 cm, respectively. Length composition of the population showed significant differences between spring and summer being females larger than males. Total length distribution did not show significant differences between cruises. Males density varied significantly between cruises while for the females no significant variation was observed. In the spring cruise, both sexes occurred at depths lower than 50 in. Females occurred in the whole area with adult occurrence only above 35 degrees 30'S. Mature males occurred throughout the area, immature males occurring in two trawls in Samborombon Bay. The summer cruise showed a discontinuous distribution of the species along the study area resulting in spatial segregation in two groups with immature females predominating in both of them.

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Um total de 4824 Mustelus schmitti foi amostrado. As fêmeas apresentaram comprimento total de 25-93 cm na primavera e 28-90 cm no verão enquanto os machos apresentaram 34-82 e de 28-77 cm, respectivamente. A composição de comprimentos da população mostrou diferenças significativas entre primavera e verão sendo as fêmeas maiores do que os machos. A distribuição de comprimento total não variou significativamente entre cruzeiros. A densidade variou significativamente entre cruzeiros nos machos sendo que a variação não foi expressiva nas fêmeas. No cruzeiro da primavera, ambos os sexos ocorreram em profundidades menores do que 50 m, as fêmeas ocorrendo em toda a área de estudo, as adultas somente acima da latitude 35°30'S. Os machos adultos foram observados em toda a área sendo que os imaturos somente em dois arrastos na Bahia de Samborombón. O cruzeiro de verão mostrou uma distribuição descontínua da espécie ao longo da área de estudo, resultando na segregação espacial em dois grupos, com predominância de fêmeas imaturas em ambos.

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Until recently, the rhynchonelliform (articulated) brachiopod fauna from the Brazilian continental shelf (western South Atlantic) was represented only by the endemic species Bouchardia rosea (Mawe), reported from coastal waters of the states of São Paulo and Rio de Janeiro. The present study, based on samples from coastal (<30 m), shelf, and continental slope waters (99-485 m), documents the South Atlantic brachiopod fauna and shows that this fauna is more widespread, diverse, and cosmopolitan than previously thought. Based on a total of 16,177 specimens, the following brachiopods have been identified: Bouchardia rosea (Family Bouchardiidae), Platidia anomioides (Family Platidiidae), Argyrotheca cf. cuneata (Family Megathyrididae), and Terebratulina sp. (Family Cancellothyrididae). In coastal settings, the fauna is overwhelmingly dominated by Bouchardia rosea. Rare juvenile (<2 mm) specimens of Argyrotheca cf. cuneata were also found at two shallow-water sites. In shelf settings (100-200 m), the fauna is more diverse and includes Bouchardia rosea, Terebratulina sp., Argyrotheca cf. cuneata, and Platidia anomioides. Notably, Bouchardia rosea was found in waters as deep as 485 m, extending the known bathymetric range of this genus. Also, the record of this brachiopod in waters of the state of Parana is the southernmost known occurrence of this species. The genera Platidia and Terebratulina are documented here for the first time for the western South Atlantic. The Brazilian brachiopod fauna shares similarities with those from the Atlantic and Indian shelves of southern Africa, and from the Antarctic, Caribbean and Mediterranean waters. The present-day brachiopods of the western South Atlantic are much more cosmopolitan than previously thought and their Cenozoic palaeobiogeographic history has to be reconsidered from that perspective.

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A new species of Ophiomisidium is described and regards about reproduction are presented. It is the first species in the genus to posses, apparently,. a brooding development. Very few specimens of species of Ophiomisidium have previously been collected, but over 3000 specimens of the new species were collected on the continental shelf and slope (60-810 m depth) off southern Brazil. They were obtained during the REVIZEE Programme, the first extensive surveys to examine Brazilian ophiuroids from depths greater than 200 m.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)