203 research outputs found

    Parasitos do matrinxã Brycon amazonicus Spix & Agassiz, 1829 (Characidae: Bryconinae) na Amazônia Central.

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    Neste capítulo descrevem-se os parasitos de matrinxã Brycon amazonicus cultivado em diferentes modalidades na Amazônia Central. Estudos demonstram que com a intensificação do cultivo deste peixe os problemas com as infecções parasitárias também podem mostrar incremento, devido às condições sanitárias, transporte e manejo inadequados. O transporte de peixes é uma maneira rápida de propagação de doenças, quando os cuidados com profilaxia e quarentena não são mantidos na piscigranja. Nestes estabelecimentos de cultivo, os estudos de parasitofauna podem auxiliar no controle e proliferação dos parasitos, evitando assim perdas econômicas significativas para o produtor.bitstream/item/211044/1/CPAF-AP-Parasitos-de-matrinxa.pd

    Ocorrência de monogenóides na engorda de tambaqui (Colossoma macropomum).

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    O tambaqui (Colossoma macropomum) é a espécie mais criada na região Norte do Brasil e na sua criação há o registro de vários parasitos com potencial patogênico. Entre eles encontram-se protozoários, mixosporídeos, crustáceos, acantocéfalos e os monogenóides. Este último grupo apresenta altos valores de intensidade parasitária em peixes cultivados, sendo caracterizados pela presença de um aparelho de fixação, o haptor, que provoca uma série de reações, podendo culminar em hipersecreção de muco, o que pode levar os animais à morte por asfixia, ou ainda provocar lesões facilitando a penetração de agentes secundários, sendo, portanto considerado este parasita um obstáculo à produtividade dos animais em criação intensiva. Assim, este estudo teve por objetivo avaliar a ocorrência de monogenóides na engorda de tambaqui (Colossoma macropomum)

    Caracterização sanitária em cultivos de tambaqui no Estado do Amazonas - polo de produção de Rio Preto da Eva.

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    Introdução. Dados gerais da região onde se encontram as propriedades aquícolas. Caracterização das propriedades e manejos adotados. Características da localização e infraestrutura da propriedade. Estruturas de cultivo. Qualidade da água e preparação de viveiros. Aquisição de formas jovens. Manejo. Alimentação. Doenças. Mão-de-obra e assistência técnica. Comercialização. Considerações finais. Referências.bitstream/item/150133/1/CNPASA-2016-doc27.pd

    Rising from the Sea: Correlations between Sulfated Polysaccharides and Salinity in Plants

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    High salinity soils inhibit crop production worldwide and represent a serious agricultural problem. To meet our ever-increasing demand for food, it is essential to understand and engineer salt-resistant crops. In this study, we evaluated the occurrence and function of sulfated polysaccharides in plants. Although ubiquitously present in marine algae, the presence of sulfated polysaccharides among the species tested was restricted to halophytes, suggesting a possible correlation with salt stress or resistance. To test this hypothesis, sulfated polysaccharides from plants artificially and naturally exposed to different salinities were analyzed. Our results revealed that the sulfated polysaccharide concentration, as well as the degree to which these compounds were sulfated in halophytic species, were positively correlated with salinity. We found that sulfated polysaccharides produced by Ruppia maritima Loisel disappeared when the plant was cultivated in the absence of salt. However, subjecting the glycophyte Oryza sativa Linnaeus to salt stress did not induce the biosynthesis of sulfated polysaccharides but increased the concentration of the carboxylated polysaccharides; this finding suggests that negatively charged cell wall polysaccharides might play a role in coping with salt stress. These data suggest that the presence of sulfated polysaccharides in plants is an adaptation to high salt environments, which may have been conserved during plant evolution from marine green algae. Our results address a practical biological concept; additionally, we suggest future strategies that may be beneficial when engineering salt-resistant crops

    Fungal diversity associated to the olive moth, prays oleae Bernard : a survey for potential entomopathogenic fungi

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    Olive production is one of the main agricultural activities in Portugal. In the region of Trás-os-Montes this crop has been considerably affected by Prays oleae. In order to evaluate the diversity of fungi on P. oleae population of Trás-os-Montes olive orchards, larvae and pupae of the three annual generations (phyllophagous, antophagous and carpophagous) were collected and evaluated for fungal growth on their surface. From the 3828 larvae and pupae, a high percentage of individuals exhibited growth of a fungal agent (40.6%), particularly those from the phyllophagous generation. From all the moth generations, a total of 43 species from 24 genera were identified, but the diversity and abundance of fungal species differed between the three generations. Higher diversity was found in the carpophagous generation, followed by the antophagous and phyllophagous generations. The presence of fungi displaying entomopathogenic features was highest in the phyllophagous larvae and pupae, being B. bassiana the most abundant taxa. The first report of B. bassiana presence on P. oleae could open new strategies for the biocontrol of this major pest in olive groves, since the use of an already adapted species increases the guarantee of success of a biocontrol approach. The identification of antagonistic fungi able to control agents that cause major olive diseases, such as Verticillium dahliae, will benefit future biological control approaches for limiting this increasingly spreading pathogen.This work was supported by Science and Technology Foundation (Fundação para a Ciência e Tecnologia – FCT) project PTDC/AGR-AAM/102600/2008 “Entomopathogenic fungi associated to olive pests: isolation, characterization and selection for biological control”. The first author is grateful to the Science and Technology Foundation for the PhD grant SFRH/BD/44265/2008
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