135 resultados para Amazon River Valley
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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In Brazil, postharvest diseases caused by pathogenic microorganisms are a major problem that causes damage to around 80% of the total fruit production. In the lower middle Sao Francisco river valley numerous studies on identification and control of fungal diseases during postharvest of grapes are needed, in order to minimize losses in this step. In this context, bunches of seedless varieties 'Crimson', 'Sonaka'; 'Superior' and 'Thompson' were collected from July to November 2009, in order to identify and quantify the incidence of pathogenic fungi. The grapes were collected on five farms which specialize in the production of table grapes for export, all located in Juazeiro - BA and Petrolina - PE. During this period, 10 samples were taken. In the fruit farm five plants were used for sampling, and removal of two bunches of grapes per plant, totaling 10 bunches per variety. Subsequently, they were sent to the laboratory of Plant Pathology at UNEB/DTCS where they were placed separately in a moist chamber for 48 hours at an average temperature of 23 degrees C. After this period, isolations of berries and stems in Petri plates containing PDA - potato-dextrose-agar were carried out with 10 repetitions, which were placed on benches under laboratory conditions. From the 8th day on, the presence of Aspergillus niger, Alternaria alternata, Cladosporium herbarum, Lasiodiploidia theobromae was observed, which presented the highest incidence, as well as Rhizopus stolonifer, Penicillium expansum.
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New data are presented on the sex chromosomes of the fish species Eigenmannia virescens (Gymnotiformes, Sternopygidae). A new finding, involving the occurrence of ZZ/ ZW sex chromosomes, is described in specimens sampled from the Sao Francisco and Amazon river basins in Brazil. All individuals had a chromosome number of 2n = 38. The homologs of the sex chromosome pair from the Sao Francisco river basin sample differed only in their morphology, while those from the Amazonian sample differed both in morphology and heterochromatin pattern. A possible model for the evolution of the sex chromosomes in E virescens is proposed, including data from populations from the Parana (Brazil) river basin, in which male heterogamety has already been described. The occurrence of different sex chromosome systems in species and populations of the neotropical freshwater fish fauna is discussed. Copyright (C) 2002 S. Karger AG, Basel.
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The importance of genetic evaluations in aquaculture programmes has been increased significantly not only to improve effectiveness of hatchery production but also to maintain genetic diversity. In the present study, wild and captive populations of a commercially important neotropical freshwater fish, Brycon cephalus (Amazonian matrincha), were analyzed in order to evaluate the levels of genetic diversity in a breeding programme at a Brazilian research institute of tropical fish. Random Amplified Polymorphic DNA fingerprinting was used to access the genetic variability of a wild stock from the Amazon River and of three captive stocks that correspond to consecutive generations from the fishery culture. Although farmed stocks showed considerably lower genetic variation than the wild population, a significantly higher level of polymorphism was detected in the third hatchery generation. The results seem to reflect a common breeding practice on several hatchery fish programmes that use a small number of parents as broodstocks, obtaining reproductive success with few non-identified mating couples. The obtained data were useful for discussing suitable strategies for the genetic management and biodiversity conservation of this species.
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In this paper, the occurrence and new morphological data of Unilatus unilatus Mizelle et Kritsky, 1967 from the gills of Hypostomus strigaticeps (Regan, 1907), Hypostomus regani (Ihering, 1905), and Hypostomus iheringii (Regan, 1908) from the Chavantes reservoir, So Paulo State, Brazil are reported. Unilatus unilatus from this reservoir presents differences in relation to the holotype previously described such as, eggs with no bifid or trifid filament and a rounded termination, anterior bar slightly curved with a posterior projection, and posterior bar which may present three shapes. This is the first record of U. unilatus in southeastern Brazil outside the Amazon River Basin, with H. strigaticeps, H. regani and H. iheringii as new hosts.
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Marine biological invasions have been regarded as one of the major causes of native biodiversity loss, with shipping and aquaculture being the leading contributors for the introductions of alien species in aquatic ecosystems. In the present study, five aquatic alien species (one mollusk, three crustaceans and one fish species) were detected during dives, shore searches and from the fisheries on the coast of the Delta do Parnaiba Environmental Protection Area, in the States of Piaui and Maranhao, Northeastern Brazil. The species were the bicolor purse-oyster Isognomon bicolor, the whiteleg shrimp Litopenaeus vannamei, the giant river prawn Macrobrachium rosenbergii, the Indo-Pacific swimming crab Charybdis hellerii and, the muzzled blenny Omobranchus punctatus. Ballast water (I. bicolor, C. hellerii, and O. punctatus) and aquaculture activities (L. vannamei and M. rosenbergii) in adjacent areas are the most likely vectors of introduction. All exotic species found have potential impact risks to the environment because they are able to compete against native species for resources (food and habitat). Isognomon bicolor share the same habitat and food items with the native bivalve species of mussels and barnacles. Litopenaeus vannamei share the same habitat and food items with the native penaeids such as the pinkspot shrimp Farfantepenaeus brasiliensis, the Southern brown shrimp Farfantepenaeus subtilis, and the Southern white shrimp Litopenaeus schmitti, and in the past few years L. vannamei was responsible for a viral epidemics in the cultivation tanks that could be transmitted to native penaeid shrimps. Charybdis hellerii is also able to cause impacts on the local fisheries as the species can decrease the populations of native portunid crabs which are commercialized in the studied region. Macrobrachium rosenbergii may be sharing natural resources with the Amazon River prawn Macrobrachium amazonicum. Omobranchus punctatus shares habit with the native redlip blenny Ophioblennius atlanticus and other fishes, such as the frillfin goby Bathigobius soporator. Some immediate remedial measures to prevent further introductions from ballast water and shrimp farm ponds should be: (i) to prevent the release of ballast water by ship/vessels in the region; (ii) to reroute all effluent waters from shrimp rearing facilities through an underground or above-ground dry well; (iii) to install adequate sand and gravel filter which will allow passage of water but not livestock; (iv) outdoor shrimp pounds located on floodable land should be diked, and; (v) to promote environmental awareness of those directly involved with ballast water (crews of ship/vessels) and shrimp farms in the region. Rev. Biol. Trop. 58 (3): 909-923. Epub 2010 September 01.
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É estudado o relacionamento entre a fisiografia e os solos evoluídos a partir de sedimentos cenozóicos, de textura e composição variáveis, depositados sob a ação do rio São Francisco e tributários. A região (vale do rio Jequitai, MG) é caracterizada por um clima sub-úmido, onde o regime de umidade do solo é ústico e o de temperatura isotérmico. Foram coletados 5 pedons dispostos numa topossequência. Na posição mais antiga (pleistocênica), o solo apresenta-se em um estágio de intensa alteração (Typic Haplustox). Os demais solos encontram-se sobre sedimentos holocênicos, compondo a planície aluvial do rio São Francisco e são, mineralogicamente, mais jovens, com horizonte argílico, representado por ultissol e molissol, ocorrência esta pouco comum em situações de planície aluvial recente. No pedon 1 (Typic Haplustox), os minerais primários intemperizáveis inexistem na fração grosseira. O pedon 2 (Plinthic Haplustult) apresenta na fração areia um acréscimo em profundidade de minerais de fácil alteração. Na fração silte, os feldspatos já estão em fase de alteração. Os pedons 3 (Oxic Plintaquult), 4 (Fluventic Plinthustult) e 5 (Fluventic Argiustol) mostram elevadas proporções de minerais primários de fácil alteração (placioclásios calco-sódicos, hornblenda), principalmente nas frações areia e silte. A ocorrência destes minerais associa-se a um processo deposicional recente, aliado às condições de clima e drenagem locais.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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1. Until the late 1960s, Euterpe edulis was the most important edible palm species in the Brazilian markets. Since then, overharvesting of natural stands and the limited scope of plantations have caused the industry to shift to the multistemmed E, oleracea from the Amazon river estuary.2, As a result of the relocation of the industry, the structure of the palm harvesting industry has changed and illegal trade has continued to exploit the remaining natural stands of E, edulis.3, it is suggested that, to avoid the total harvesting of E. edulis and to achieve sustainable management of the palm heart, it will be necessary to diversify the local economy, create incentives for small land owners to improve their management practices, while keeping their competitiveness against the illegal trade, create the incentive of new sources of palm hearts and create a 'green stamping' For management palms.4, Transformation of the illegal structure of the palm heart industry is probably the only solution to avoid the total depletion of the wild stands of E. edulis.
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Dolphins of the genus Sotalia are found along the Caribbean and Atlantic coasts of Central and South America and in the Amazon River and most of its tributaries. At present, the taxonomy of these dolphins remains unresolved. Although five species were described in the late 1800s, only one species is recognized currently (Sotalia fluviatilis) with two ecotypes or subspecies, the coastal subspecies (Sotalia fluviatilis guianensis) and the riverine subspecies (Sotalia fluviatilis fluviatilis). Recent morphometric analyses, as well as mitochondrial DNA analysis, suggested recognition of each subspecies as separate species. Here we review the history of the classification of this genus and present new genetic evidence from ten nuclear and three mitochondrial genes supporting the elevation of each subspecies to the species level under the Genealogical/Lineage Concordance Species Concept and the criterion of irreversible divergence. We also review additional evidence for this taxonomic revision from previously published and unpublished genetic, morphological, and ecological studies. We propose the common name costero for the coastal species, Sotalia guianensis (Van Beneden 1864), and accept the previously proposed tucuxi dolphin, Sotalia fluviatilis (Gervais, 1853), for the riverine species.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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This paper presents the gravity survey refinement of the Paraíba do Sul river valley, east region of São Paulo state, by acquisition of 646 gravity stations. Further than the traditional Free-Air and Bouguer corrections, it was necessary to apply the Terrain Correction due the proximity of the Mantiqueira and Mar mountain ranges. An enhanced understanding of Taubaté Basin structural framework was the main objetive of this work. As result, we present the Bouguer Gravity Map of the east region of São Paulo State and the Residual Bouguer Gravity Map generated by Upward Continuation and High-pass filtering. The 2D Gravity Modeling was applied in 4 sections, using bi-dimensional models for the bodies that produced the anomalies (Talwani Method). After integrating the gravity data with the interpretation of 11 seismic sections, it was possible to delineate the Taubate Basin structural framework, which shows an utmost sedimentary thickness of 800 m in the depocenters. It was also interpreted an ultramaphic alkaline plug in the subsurface of Caçapava city.
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Distribution patterns of most of the 20 Neotropical freshwater turtles belonging to the family Chelidae are usually based on few locality records. We here report on vouchered records of three species of the chelid genus Mesoclemmys in the Brazilian state of Mato Grosso. Presence of M. vanderhaegei is confirmed for the Amazon River Basin, and M. gibba and M. raniceps are recorded in Mato Grosso for the first time. © 2012 Check List and Authors.