27 resultados para Brazil, Rio Pardo

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


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Imposex is the development of male sexual characteristics, i.e., penis and/or vas deferens in females of dioecious gastropods. This phenomenon has been associated to the use of the organotin based marine antifouling paints and used worldwide as a bioindicator of pollution by the TBT (antifouling agent) as well as to evaluate the related ecological impact. This study reports imposex in Stramonita haemastoma at south coast of Rio de Janeiro State (Brazil), specifically at Sepetiba and Ilha Grande Bays. All the stations where snails were found have shown imposex. Ilha Grande Bay presented the highest values of imposex indices when compared to Sepetiba Bay. The results suggest that high concentration of shipping activities and coastal morphology are the principal causes at the most polluted sites.

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The HIV-1 subtype C has spread efficiently in the southern states of Brazil (Rio Grande do Sul, Santa Catarina and Parana). Phylogeographic studies indicate that the subtype C epidemic in southern Brazil was initiated by the introduction of a single founder virus population at some time point between 1960 and 1980, but little is known about the spatial dynamics of viral spread. A total of 135 Brazilian HIV-1 subtype C pol sequences collected from 1992 to 2009 at the three southern state capitals (Porto Alegre, Florianopolis and Curitiba) were analyzed. Maximum-likelihood and Bayesian methods were used to explore the degree of phylogenetic mixing of subtype C sequences from different cities and to reconstruct the geographical pattern of viral spread in this country region. Phylogeographic analyses supported the monophyletic origin of the HIV-1 subtype C clade circulating in southern Brazil and placed the root of that clade in Curitiba (Parana state). This analysis further suggested that Florianopolis (Santa Catarina state) is an important staging post in the subtype C dissemination displaying high viral migration rates from and to the other cities, while viral flux between Curitiba and Porto Alegre (Rio Grande do Sul state) is very low. We found a positive correlation (r(2) = 0.64) between routine travel and viral migration rates among localities. Despite the intense viral movement, phylogenetic intermixing of subtype C sequences from different Brazilian cities is lower than expected by chance. Notably, a high proportion (67%) of subtype C sequences from Porto Alegre branched within a single local monophyletic sub-cluster. These results suggest that the HIV-1 subtype C epidemic in southern Brazil has been shaped by both frequent viral migration among states and in situ dissemination of local clades.

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Leporinus obtusidens Valenciennes, 1837 and L. elongatus Valenciennes, 1850 are redescribed based on the type specimens, including those of their junior synonyms, and recently collected specimens. Leporinus obtusidens is considered to be widespread, occuring in the river drainages of La Plata, São Francisco, and Parnaíba. Leporinus aguapeiensis Campos, 1945, described from the upper Rio Paraná, and L. silvestrii Boulenger, 1902, described from the Rio Paraguay, are considered junior synonyms of L. obtusidens. Leporinus elongatus is endemic to the Rio Jequitinhonha and Rio Pardo, two eastern Brazilian river basins, and the locality cited for the lectotype, Rio São Fransico, likely to be erroneous. Leporinus crassilabris Borodin, 1929, and L. crassilabris breviceps Borodin, 1929, both described from the Rio Jequitinhonha, are considered junior synynoms of L. elongatus. A new species of Leporinus, endemic to the upper Rio Paraná, very similar and sometimes mistaken with L. obtusidens, is formally described. In addition, comments on Leporinus pachyurus Valenciennes, 1850 and on L. bimaculatus Castelnau, 1855 are provided, and a lectotype for L. bimaculatus is selected.

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Novos táxons descritos: Acanthoderini, Nesozineus osorioensis sp. nov., do Brasil (Rio Grande do Sul); Calliini, Drycothaea clara sp. nov., do Brasil (Rondônia) e Drycothaea hovorei sp. nov., do Equador (Napo); Forsteriini, Itacolomi gen. nov., espécie-tipo I. letiziae sp. nov., do Brasil (Minas Gerais); Yapyguara gen. nov., espécie-tipo Y. fusca sp. nov., da Bolívia (Santa Cruz); Xenofreini, Xenofrea zischkai sp. nov., do Equador (Napo) e da Bolívia (Santa Cruz).

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The Restinga of Marambaia is an emerged sand bar located between the Sepetiba Bay and the South Atlantic Ocean, on the south-east coast of Brazil. The objective of this study was to observe the geomorphologic evolution of the coastal zone of the Restinga of Marambaia using multitemporal satellite images acquired by multisensors from 1975 to 2004. The images were digitally segmented by a region growth algorithm and submitted to an unsupervised classification procedure (ISOSEG) followed by a raster edit based on visual interpretation. The image time-series showed a general trend of decrease in the total sand bar area with values varying from 80.61km(2) in 1975 to 78.15km(2) in 2004. The total area calculation based on the 1975 and 1978 Landsat MSS data was shown to be super-estimated in relation to the Landsat TM, Landsat ETM+, and CBERS-2 CCD data. These differences can also be associated to the relatively poorer spatial resolution of the MSS data, nominally 79m, against the 20m of the CCD data and 30m of the TM and ETM+ data. For the estimates of the width in the central portion of the sand bar the variation was from 158m (1975) to 100m (2004). The formation of a spit in the northern region of the study area was visually observed. The area of the spit was estimated, with values varying from 0.82km(2) (1975) to 0.55km(2) (2004).

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Hemigrommus silimoni is described from the Rio Juruena, upper Rio Tapajos basin, Mato Grosso State, Brazil. The new species is distinguished from all congeners, and in fact from the remaining Characidae, by the autapomorphic presence of an ocellus-like blotch on the caudal-fin dorsal lobe. The high level of fish endemicity In the Rio Juruena (upper Rio Tapajos basin) is discussed.

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A new species of the thorny catfish genus Leptodoras (family Doradidae) is described. The new species shares three characters with its congeners, the modified oral hood with distinct upper labial extensions, the first gill arch with enlarged accessory lamellae extending well onto medial face of gill filaments, and the pelvic fin inserted in anterior half of body. The new species is distinguished from congeners by having a large dark submarginal blotch on distal half of dorsal-fin spine and anteriormost dorsal-fin branched rays, lower labial extension of modified oral hood extending more posteriorly than upper labial extension, relatively few midlateral scutes, gas bladder moderately sized (not reduced), paired bony capsules on anteriormost vertebrae reduced to paired cup-like laminar ossifications separated by a triangular septum, pair of small, swelling-like diverticula on each side of the anterior chamber of gas bladder, a well-developed anterior nuchal plate, and nuchal foramina present. The new species was discovered from a single specimen collected in the rio Fresco, a tributary of the rio Xingu, and is described based on this and on additional material recently collected in the same area. A discussion of its placement within Leptodoras is also presented.

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A new species of Moenkhausia is described from Rio Xingu and Rio Tapajos basins, Brazil. The new species is distinguished from its congeners, except from Moenkhausia moisae, by having more scales in the lateral series, 43-47 (v. 23-41 in the remaining congeners). The new species is distinguished from M. moisae by its colour pattern, which consists of a dark midlateral stripe, and an asymmetrical caudal blotch (inconspicuous or faded in specimens from the Rio Arinos) continuous with the midlateral stripe (v. narrow dark midlateral line and conspicuous, regularly rounded and symmetrical blotch not continuous with the midlateral line). The new species is putatively assumed to be mimetic to Jupiaba apenima, in the Rio Xingu and Rio Teles Pires drainages, and to Jupiaba yarina in the Rio Arinos. The two species of Jupiaba are sympatric and remarkably similar in size, general external morphology and colouration to the new species. A small difference occurs in the colouration between the two species of Jupiaba and is also observed in the two respectively sympatric morphotypes of the new species of Moenkhausia. The occurrence of polymorphic Batesian mimicry is therefore discussed for neotropical freshwater fishes. (C) 2009 The Authors Journal compilation (C) 2009 The Fisheries Society of the British Isles

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Two new species of Jupiaba Zanata are described from Brazil. Jupiaba iasy, new species, is described from rio Teles Pires and rio Jamanxim, tributaries of rio Tapajos, and from rio Aripuana, in the rio Madeira drainage. It is distinguished from its congeners by its color pattern consisting of a single posteriorly displaced dark crescent-shaped humeral blotch, situated over the first 5 to 7 lateral line scales, and an inconspicuous dark spot at the end of caudal peduncle. It also differs from all remaining Jupiaba for the following combination of characters: 34-36 lateral line scales, 19-21 branched anal-fin rays, 8-10 predorsal scales arranged in a regular row, 6 horizontal series of scales above and 4 series below lateral line, body depth 32.3-36.1% of SL, and absence of filamentous rays in the first dorsal and anal-fin rays. Jupiaba paranatinga, new species, is described from rio Teles Pires, tributary of rio Tapajos. It is distinguished by having 34-35 lateral line scales, two vertically elongated humeral blotches, a conspicuous caudal spot at the end of the caudal peduncle, extending over 8-10 median caudal-fin rays, eye diameter 43.7-46.9% of HL, and relatively low body depth (31.3-35.5% of SL). Additionally, comments on the putative relationships of the new species with their congeners and an updated key to the species of the genus are provided.

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Gymnotus tiquie, new species, is described from the Rio Tiquie, a tributary of the Uaupes (Vaupes) in the upper Negro basin, Amazonas, Brazil. The new species was collected in non-floodplain (terra firme) streams, where it occurs sympatrically and syntopically with two geographically widespread congeners, the type species of the genus, G. carapo, and G. coropinae. The new species is diagnosed by a unique combination of morphometric, meristic, and osteological traits, and by a characteristic color pattern in which the dark oblique pigment bands, diverse in shape and design, are divided into band-pairs along the length of the body, in which the band-pairs are often recurved (dorsally concave), more variable, and often reticulated in the abdominal region, and in which the pale inter-bands meet at the dorsal midline along most of the length of the body. Gymnotus tiquie is a member of the G. pantherinus species group, with which it shares the presence of one (vs. two) pore in the dorsolateral portion of the preopercle (except in G. pantanal and G. anguillaris), needle-shaped (vs. conical or arrowhead-shaped) teeth on the dentary and premaxilla, and a slender body (BD 5.6-10.6% HL vs. deep 8.7-13.5%, except G. chaviro, G. curupira, G. varzea, G. chimarrao, G. maculosus, G. henni, and G. inaequilabiatus that also have a slender body). Gymnotus tiquie is most similar in overall appearance to G. cataniapo of the upper Orinoco. These two species share three unique features within the G. pantherinus group: dark band-pairs with wavy irregular margins along the length of the body, a long body cavity with 45 or more pre-caudal vertebrae, and a darkly pigmented membrane in the caudal region of the anal fin.

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Thirty-eight stations were sampled in Guanabara Bay, Rio de Janeiro, Brazil, to assess the spatio-temporal diversity and biomass of sublittoral polychaetes. Samples were collected during the dry (September 2000) and rainy season (May 2001) in shallow sublittoral sediments. The polychaete spatial composition showed a heterogeneous distribution throughout the bay. A negative gradient of diversity and biomass was observed towards the inner parts of the bay and sheltered areas. A wide azoic area was found inside the bay. Some high-biomass and low-diversity spots were found near a sewage-discharge point. In these areas, the polychaete biomass increased after the rainy season. A diversified polychaete community was identified around the bay mouth, with no dramatic changes of this pattern between the two sampling periods. Deposit-feeders were dominant in the entire study area. The relative importance of carnivores and omnivores increased towards the outer sector, at stations with coarse sediment fractions. Guanabara Bay can be divided into three main zones with respect to environmental conditions and polychaete diversity and biomass patterns: A) High polychaete diversity, hydrodynamically exposed areas composed of sandy, oxidized or moderately reduced sediments with normoxic conditions in the water column. B) Low diversity and high biomass of deposit and suspension-feeding polychaete species in the middle part of the bay near continental inflows, comprising stations sharing similar proportions of silt, clay and fine sands. C) Azoic area or an impoverished polychaete community in hydrodynamically low-energy areas of silt and clay with extremely reduced sediments, high total organic matter content and hypoxic conditions in the water column, located essentially from the mid-bay towards the north sector. High total organic matter content and hypoxic conditions combined with slow water renewal in the inner bay seemed to play a key role in the polychaete diversity and biomass. Sedimentation processes and organic load coming from untreated sewage into the bay may have negatively affected the survivorship of the fauna.

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Population structure of the lancelet Branchiostoma caribaeum Sandevall, 1853 was studied in four surveys, corresponding to austral seasons, in a tropical bay, southeast of Brazil. Abundance was higher in the spring and was positively correlated to coarse sediments, limiting its occurrence to some sectors of the sampling area. Body length and biomass differed seasonally but not between sexes. Sexually mature individuals occurred in all seasons, suggesting continuous breeding that is typical of tropical species. Variation in the frequency of small specimens indicates temporal differences in the intensity of breeding. The body length of recruits differed from other population of lancelets and the small length which B. caribaeum attained sexual maturity in Guanabara Bay may be related to local environmental stress or the great availability of food.

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Molecular findings that confirmed the participation of ovine herpesvirus 2 (OVH-2) in the lesions that were consistent with those observed in malignant catarrhal fever of cattle are described. Three mixed-breed cattle from Rio Grande do Norte state demonstrated clinical manifestations that included mucopurulent nasal discharge, corneal opacity and motor incoordination. Routine necropsy examination demonstrated ulcerations and hemorrhage of the oral cavity, corneal opacity, and lymph node enlargement. Significant histopathological findings included widespread necrotizing vasculitis, non-suppurative meningoencephalitis, lymphocytic interstitial nephritis and hepatitis, and thrombosis. PCR assay performed on DNA extracted from kidney and mesenteric lymph node of one animal amplified a product of 423 base pairs corresponding to a target sequence within the ovine herpesvirus 2 (OVH-2) tegument protein gene. Direct sequencing of the PCR products, from extracted DNA of the kidney and mesenteric lymph node of one cow, amplified the partial nucleotide sequences (423 base pairs) of OVH-2 tegument protein gene. Blast analysis confirmed that these sequences have 98-100% identity with similar OVH-2 sequences deposited in GenBank. Phylogenetic analyses, based on the deduced amino acid sequences, demonstrated that the strain of OVH-2 circulating in ruminants from the Brazilian states of Rio Grande do Norte and Minas Gerais are similar to that identified in other geographical locations. These findings confirmed the active participation of OVH-2 in the classical manifestations of sheep associated malignant catarrhal fever.

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A new armored catfish species of the genus Hypostomus is described from the upper rio Xingu basin, Mato Grosso State, Brazil. The new species is diagnosed from congeners by having high number of teeth (58 to 101, mean 77 on premaxilla, and 58 to 105, mean 80 on dentary), dark spots over body and fins, and abdomen mostly naked. The new species is known from the rapids of the rio Culuene, where it is sympatric with Hypostomus faveolus.

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The occurrence of ochratoxin A (OTA) in wine from 2002 to 2008 harvest, traded in Rio de Janeiro State, was evaluated by analysing 43 national and 37 imported wines from Argentina (32) and Chile (5), adding up to 80 samples in total. OTA determination was performed using immunoaffinity columns and high-performance liquid chromatography. In 80 wine samples analysed, 25 (31.3%) were positive, presenting levels greater than 0.020 ng OTA mL(-1). It was not detected in imported wines. Within national wines, 58.1% of the samples were contaminated, with levels ranging from 0.020 to 0.050 ng mL(-1). The toxin was detected in 18 (69.2%) of 26 samples analysed of red table wine. Wines from 2008 harvest presented 84.6% of samples contaminated in 13 samples analysed. Despite the levels found in this study, they are below Brazilian tolerance limits. Nevertheless, the presence of OTA as found contributes to the human exposure to this toxin.