696 resultados para Linnaeus
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The starfish, Asterias rubens, preys on mussels (Mytilus edulis), which are relaid during benthic cultivation processes. Starfish mops, a modified dredge used to remove starfish from mussel cultivation beds, are used in several fisheries today but few studies have attempted to quantify the effectiveness of this method in removing starfish. This study tested the effectiveness of starfish mopping to reduce starfish numbers on mussel beds in Belfast Lough, Northern Ireland. Video surveys to determine starfish densities on mussel beds were conducted between October 2013 and December 2014 using a GoPro™ camera attached to starfish mops. This allowed us to firstly test whether starfish density varied among mussel beds and to investigate how fluctuations in starfish numbers may vary in relationship to starfish ecology. We then estimated the efficiency of mops at removing starfish from mussel beds by comparing densities of starfish on beds, as determined using video footage, with densities removed by mops. Starfish abundance was similar among different mussel beds during this study. The efficiency of mops at removing estimated starfish aggregations varied among mussel beds (4–78%) and the mean reduction in starfish abundance was 27% (± SE 3.2). The effectiveness of mops at reducing starfish abundance was shown to decline as the initial density of starfish on mussel beds increased. It can be recommended that the exact deployment technique of mops on mussel beds should vary depending on the density of starfish locally. The area of mussel bed covered by mops during a tow, for example, should be less when starfish densities are high, to maintain efficiencies throughout the full length of tows and to optimise the removal of starfish from mussel beds. This strategy, by reducing abundance of a major predator, could assist in reducing losses in the mussel cultivation industry.
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Fish belonging to the genus Macroramphosus are distributed throughout the Atlantic, Indian and PaciWc oceans. Some authors consider this genus monotypic, Macroramphosus scolopax being the only valid species. Other authors consider (based on several morphological and ecological characters) that another species (Macroramphosus gracilis) exists and occurs frequently in sympatry with the Wrst one. Intermediate forms are also reported in literature. In this paper, using the mitochondrial control region and the nuclear Wrst S7 intron markers, we failed to Wnd genetic diVerences between individuals considered to belong to both species as well as the intermediate forms. Our results suggest that in the northeastern Atlantic, Macroramphosus is represented by a single species, M. scolopax, with diVerent morphotypes interbreeding in the sampling areas.
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Dissertação de Mestrado, Biologia Marinha, Especialização em Aquacultura e Pescas, Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve, 2008
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Dissertação de Mestrado, Aquacultura e Pescas, Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve, 2006
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Dissertação de mest., Biologia Marinha, Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve, 2009
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Dissertação de Mestrado, Biologia Marinha, Especialização em Biotecnologia Marinha, Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve, 2008
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Dissertação de mest., Tecnologia de Alimentos, Instituto Superior de Engenharia, Univ. do Algarve, 2013
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Dissertação de Mestrado, Recursos Biológicos do Mar, Unidade de Ciências e Tecnologias dos Recursos Aquáticos, Universidade do Algarve, 1998
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Dissertação de mestrado, Aquacultura e Pescas, Faculdade de Ciências e Tecnologia, Uniersidade do Algarve, 2015
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Tesis (Maestría en Ciencias con Especialidad en Microbiología Industrial) UANL
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Tesis (Maestría en Ciencias con Especialidad en Microbiología) UANL
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Tesis (Maestría en Ciencias con Especialidad en Química de Productos Naturales) UANL
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Tesis (Maestría en Ciencias con Especialidad en Entomología Médica) U.A.N.L.
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Tesis (Maestría en Ciencias con Especialidad en Entomología Médica) U.A.N.L.
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Tesis (Doctor en Ciencias con Acentuación en Entomología Médica) UANL, 2012