614 resultados para tuna


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A survey of Pacific coral reef fishes for sanguinicolids revealed that two species of Lutjanidae (Lutjanus argentimaculatus, L. bohar), six species of Siganidae (Siganus corallinus, S. fuscescens, S. lineatus, S. margaritiferus, S. punctatus, S. vulpinus), seven species of Chaetodontidae (Chaetodon aureofasciatus, C. citrinellus, C. flavirostris, C. lineolatus, C. reticulatus, C. ulietensis, C. unimaculatus), three species of Scombridae (Euthynnus affinis, Scomberomorus commerson, S. munroi) and three species of Scaridae (Chlorurus microrhinos, Scarus frenatus, S. ghobban) were infected with morphologically similar sanguinicolids. These flukes have a flat elliptical body, a vestigial oral sucker, a single testis, separate genital pores and a post-ovarian uterus. However, these species clearly belong in two genera based on the position of the testis and genital pores. Sanguinicolids from Lutjanidae, Siganidae, Chaetodontidae and Scombridae belong in Cardicola Short, 1953; the testis originates anteriorly to, or at the anterior end of, the intercaecal field and does not extend posteriorly to it, the male genital pore opens laterally to the sinistral lateral nerve chord and the female pore opens near the level of the ootype ( may be anterior, lateral or posterior to it) antero-dextral to the male pore. Those from Scaridae are placed in a new genus, Braya; the testis originates near the posterior end of the intercaecal field and extends posteriorly to it, the male pore opens medially at the posterior end of the body and the female pore opens posterior to the ootype, antero-sinistral to the male pore. The second internal transcribed spacer (ITS2) of ribosomal DNA from these sanguinicolids and a known species, Cardicola forsteri Cribb, Daintith & Munday, 2000, were sequenced, aligned and analysed to test the distinctness of the putative new species. Results from morphological comparisons and molecular analyses suggest the presence of 18 putative species; 11 are described on the basis of combined morphological and molecular data and seven are not because they are characterised solely by molecular sequences or to few morphological specimens (n= one). There was usually a correlation between levels of morphological and genetic distinction in that pairs of species with the greatest genetic separation were also the least morphologically similar. The exception in this regard was the combination of Cardicola tantabiddii n. sp. from S. fuscescens from Ningaloo Reef ( Western Australia) and Cardicola sp. 2 from the same host from Heron Island ( Great Barrier Reef). These two parasite/ host/location combinations had identical ITS2 sequences but appeared to differ morphologically ( however, this could simply be due to a lack of morphological material for Cardicola sp. 2). Only one putative species ( Cardicola sp. 1) was found in more than one location; most host species harboured distinct species in each geographical location surveyed ( for example, S. corallinus from Heron and Lizard Islands) and some ( for example, S. punctatus, S. fuscescens and Chlorurus microrhinos) harboured two species at a single location. Distance analysis of ITS2 showed that nine species from siganids, three from scombrids and five from scarids formed monophyletic clades to the exclusion of sanguinicolids from the other host families. Cardicola milleri n. sp. and C. chaetodontis Yamaguti, 1970 from lutjanids and chaetodontids, respectively, were the only representatives from those families that were sequenced. Within the clade formed by sanguinicolids from Siganidae there wasa further division of species; species from the morphologically similar S. fuscescens and S. margaritiferus formed a monophyletic group to the exclusion of sanguinicolids from all other siganid species.

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The failures of traditional target-species management have led many to propose an ecosystem approach to fisheries to promote sustainability. The ecosystem approach is necessary, especially to account for fishery-ecosystem interactions, but by itself is not sufficient to address two important factors contributing to unsustainable fisheries: inappropriate incentives bearing on fishers and the ineffective governance that frequently exists in commercial, developed fisheries managed primarily by total-harvest limits and input controls. We contend that much greater emphasis must be placed on fisher motivation when managing fisheries. Using evidence from more than a dozen natural experiments in commercial fisheries, we argue that incentive-based approaches that better specify community and individual harvest or territorial rights and price ecosystem services and that are coupled with public research, monitoring, and effective oversight promote sustainable fisheries.

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We thank Sean Tracey and Jaime McAllister for supplying albacore and southern bluefin tuna samples, Eva Giacomello for collecting the skipjack tuna sample, Elena Sarropoulou for providing the Atlantic bonito assembly, Helen Hipperson for assistance in the lab, Barbara Block and Ziheng Yang for advice, the editors and reviewers for comments, and the Leverhulme Trust and BBSRC for funding

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Four marine fish species are among the most important on the world market: cod, salmon, tuna, and sea bass. While the supply of North American and European markets for two of these species - Atlantic salmon and European sea bass - mainly comes from fish farming, Atlantic cod and tunas are mainly caught from wild stocks. We address the question what will be the status of these wild stocks in the midterm future, in the year 2048, to be specific. Whereas the effects of climate change and ecological driving forces on fish stocks have already gained much attention, our prime interest is in studying the effects of changing economic drivers, as well as the impact of variable management effectiveness. Using a process-based ecological-economic multispecies optimization model, we assess the future stock status under different scenarios of change. We simulate (i) technological progress in fishing, (ii) increasing demand for fish, and (iii) increasing supply of farmed fish, as well as the interplay of these driving forces under different sce- narios of (limited) fishery management effectiveness. We find that economic change has a substantial effect on fish populations. Increasing aquaculture production can dampen the fishing pressure on wild stocks, but this effect is likely to be overwhelmed by increasing demand and technological progress, both increasing fishing pressure. The only solution to avoid collapse of the majority of stocks is institutional change to improve management effectiveness significantly above the current state. We conclude that full recognition of economic drivers of change will be needed to successfully develop an integrated ecosystem management and to sustain the wild fish stocks until 2048 and beyond.

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This collection contains measurements of abundance and diversity of different groups of aboveground invertebrates sampled on the plots of the different sub-experiments at the field site of a large grassland biodiversity experiment (the Jena Experiment; see further details below). In the main experiment, 82 grassland plots of 20 x 20 m were established from a pool of 60 species belonging to four functional groups (grasses, legumes, tall and small herbs). In May 2002, varying numbers of plant species from this species pool were sown into the plots to create a gradient of plant species richness (1, 2, 4, 8, 16 and 60 species) and functional richness (1, 2, 3, 4 functional groups). Plots were maintained by bi-annual weeding and mowing. The following series of datasets are contained in this collection: 1. Measurements of ant abundance (number of individuals attracted to baits) and ant occurrence (binary data) in the Main Experiment in 2006 and 2013. Ants where sampled using two types of baited traps receiving ~10g of Tuna or ~10g of honey/Sucrose. After 30min the occurrence (presence = 1 / absence = 0) and abundance (number) of ants at the two types of baits was recorded and pooled per plot.

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This data set contains measurements of ant abundance (number of individuals observed at the baits) and ant occurrence (binary data) measured in the Main Experiment plots of a large grassland biodiversity experiment (the Jena Experiment; see further details below). Ants were sampled in 80 plots of the Main Experiment using baited traps in July 2006. In each plot two petri dishes were set on the ground, one received ~10g of Tuna the other ~10g of sugar (Sucrose). After 30min the occurrence (presence = 1 / absence = 0) and abundance (number) of ants at the two baits was recorded. Given is, per plot, the sum of ants attracted to the two different baits. In the Main Experiment, 82 grassland plots of 20 x 20 m were established from a pool of 60 species belonging to four functional groups (grasses, legumes, tall and small herbs). In May 2002, varying numbers of plant species from this species pool were sown in the plots to create a gradient of plant species richness (1, 2, 4, 8, 16 and 60 species) and functional richness (1, 2, 3, or 4 functional groups). Plots were maintained by bi-annual weeding and mowing.

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This data set contains measurements of ant abundance (number of individuals attracted to baits) and ant occurrence (binary data) measured in the Main Experiment plots of a large grassland biodiversity experiment (the Jena Experiment; see further details below). In the Main Experiment, 82 grassland plots of 20 x 20 m were established from a pool of 60 species belonging to four functional groups (grasses, legumes, tall and small herbs). In May 2002, varying numbers of plant species from this species pool were sown in the plots to create a gradient of plant species richness (1, 2, 4, 8, 16 and 60 species) and functional richness (1, 2, 3, or 4 functional groups). Plots were maintained by bi-annual weeding and mowing. Ants where sampled in 80 plots of the Main Experiment using baited traps end of July/ beginning of August 2013. Sampling took place 36 days after the end of a major flooding of the field site that lasted for several weeks (see DOI flood descriptor). In each plot two petri dishes were set on the ground, one received ~10g of Tuna the other ~10g of Honey. After 30min the occurrence (presence = 1 / absence = 0) and abundance (number) of ants at the two baits was recorded. Given is, per plot, the sum of ants attracted to the two different baits.

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Highlights • We study diel behavioural differences in activity patterns in bigeye tuna. • Daytime activity patterns showed scale free movements consistent with searching. • Night-time activity showed simpler movements indicative of rich patch exploitation. • The results confirm predictions of the Lévy foraging hypothesis.

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Highlights • We study diel behavioural differences in activity patterns in bigeye tuna. • Daytime activity patterns showed scale free movements consistent with searching. • Night-time activity showed simpler movements indicative of rich patch exploitation. • The results confirm predictions of the Lévy foraging hypothesis.

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Nos últimos dois anos letivos o Conselho Pedagógico da Escola Superior de Enfermagem de Coimbra (ESEnfC) implementou um Programa de integração de estudantes do 1º ciclo de estudos em Enfermagem, tendo como objetivos promover a sua integração na ESEnfC, seu funcionamento e serviços, contribuir para a integração na vida académica e comunidade educativa, facilitar a interação com professores, outros estudantes e funcionários. Em parceria com a coordenação do 1º ano, organizaram-se e dinamizaram-se 3 dias de atividades na primeira semana do ano letivo, sob o lema "À descoberta da ESEnfC à luz dos seus valores matriciais" em setembro de 2013 e "À descoberta da ESEnfC à luz dos seus Projetos" em setembro de 2014. Abrangeram-se cerca de 320 estudantes (2013 e 2014) e envolveram-se professores (32/2013; 36/2014) e estudantes (30/2013; 30/2014) de referência, estruturas estudantis (Associação Estudantes, Comissão Praxe e Tuna), Unidades Diferenciadas, Gabinetes e Serviços (e.g. Gabinete Apoio Projetos, Conselho Qualidade e Avaliação, Unidade Investigação). Metodologicamente organizaram-se grupos de 15 estudantes do 1º ano orientados respetivamente por 2 professores e 2 estudantes nas sessões de acolhimento com os presidentes dos órgãos, nas visitas aos 3 polos e aos principais pontos estratégicos (e.g. Centro Simulação, Biblioteca) e nas atividades integrativas. Em 2013 propôs-se a realização de sessões de brainstorming, atribuindo a cada grupo um valor matricial da ESEnfC, que resultou numa síntese reflexiva e 'nuvem de palavras' por grupo e apresentada em plenário. Em 2014, a cada grupo foi apresentado um Projeto da ESEnfC propondo-se a construção de cartaz digital representativo e respetiva síntese reflexiva, com apresentação em plenário. Dos estudos de opinião (inicial em setembro e de impacto em fevereiro) realizados pelo Conselho Qualidade e Avaliação, em 2013 e 2014, a satisfação dos estudantes (expressa numa escala de Muito Baixo a Muito Elevado) situa-se sobretudo nos níveis Elevado e Muito Elevado relativamente ao Programa e ao seu contributo na integração à Escola, ensino superior e novo ambiente, facilitando a interação, comunicação e relação entre estudantes e comunidade escolar. No estudo inicial 80% dos estudantes atribuíram Muita Importância a este tipo de atividades e 90% dos estudantes gostaria de participar futuramente no Programa. Registou-se a sugestão de melhoria futura na integração dos estudantes da 2ª e 3ª fase de colocação no ensino superior. Ressalta a importância que este Programa assume na integração dos estudantes no Ensino Superior, na ESEnfC e na prossecução dos objetivos estratégicos propostos de promover um ambiente institucional de proximidade e de trabalho colaborativo de toda a comunidade educativa, envolvendo estudantes, docentes e funcionários não docentes.

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In order to clear up possibilities to get bluefin tuna of various age in Eastern Atlantic, main conclusions on availability of bluefin in Eastern Atalntic are given, using results of International Commission for Conservation of Atlantic Tuna.

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Chemical speciation in foodstuffs is of uttermost importance since it is nowadays recognized that both toxicity and bioavailability of an element depend on the chemical form in which the element is present. Regarding arsenic, inorganic species are classified as carcinogenic while organic arsenic, such as arsenobetaine (AsB) or arsenocholine (AsC), is considered less toxic or even non-toxic. Coupling a High Performance Liquid Chromatographer (HPLC) with an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) combines the power of separation of the first with the selectivity and sensitivity of the second. The present work aims at developing a method, using HPLC-ICP-MS technique, to identify and quantify the chemical species of arsenic present in two food matrices, rice and fish. Two extraction methods, ultrasound and microwave, and different settings were studied. The best method was chosen based on recovery percentages. To ensure that no interconversion of species was occurring, individual spikes of each species of arsenic were made in both matrices and recovery rates were calculated. To guaranty accurate results reference material BCR-627 TUNA FISH, containing certified values for AsB and DMA, was analyzed. Chromatographic separation was achieved using an anion exchange column, HAMILTON-PRP X-100, which allowed to separate the four arsenic species for which standards were available (AsB, dimethylarsenic (DMA), arsenite (AsIII), arsenate (AsV). The mobile phase was chosen based on scientific literature and adjusted to laboratory conditions. Different gradients were studied. As a result we verified that the arsenic species present in both matrices were not the same. While in fish 90% of the arsenic present was in the form of arsenobetaine, in rice 80% of arsenic was present as DMA and 20% as inorganic arsenic.

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Seafood products fraud, the misrepresentation of them, have been discovered all around the world in different forms as false labeling, species substitution, short-weighting or over glazing in order to hide the correct identity, origin or weight of the seafood products. Due to the value of seafood products such as canned tuna, swordfish or grouper, these species are the subject of the commercial fraud is mainly there placement of valuable species with other little or no value species. A similar situation occurs with the shelled shrimp or shellfish that are reduced into pieces for the commercialization. Food fraud by species substitution is an emerging risk given the increasingly global food supply chain and the potential food safety issues. Economic food fraud is committed when food is deliberately placed on the market, for financial gain deceiving consumers (Woolfe, M. & Primrose, S. 2004). As a result of the increased demand and the globalization of the seafood supply, more fish species are encountered in the market. In this scenary, it becomes essential to unequivocally identify the species. The traditional taxonomy, based primarily on identification keys of species, has shown a number of limitations in the use of the distinctive features in many animal taxa, amplified when fish, crustacean or shellfish are commercially transformed. Many fish species show a similar texture, thus the certification of fish products is particularly important when fishes have undergone procedures which affect the overall anatomical structure, such as heading, slicing or filleting (Marko et al., 2004). The absence of morphological traits, a main characteristic usually used to identify animal species, represents a challenge and molecular identification methods are required. Among them, DNA-based methods are more frequently employed for food authentication (Lockley & Bardsley, 2000). In addition to food authentication and traceability, studies of taxonomy, population and conservation genetics as well as analysis of dietary habits and prey selection, also rely on genetic analyses including the DNA barcoding technology (Arroyave & Stiassny, 2014; Galimberti et al., 2013; Mafra, Ferreira, & Oliveira, 2008; Nicolé et al., 2012; Rasmussen & Morrissey, 2008), consisting in PCR amplification and sequencing of a COI mitochondrial gene specific region. The system proposed by P. Hebert et al. (2003) locates inside the mitochondrial COI gene (cytochrome oxidase subunit I) the bioidentification system useful in taxonomic identification of species (Lo Brutto et al., 2007). The COI region, used for genetic identification - DNA barcode - is short enough to allow, with the current technology, to decode sequence (the pairs of nucleotide bases) in a single step. Despite, this region only represents a tiny fraction of the mitochondrial DNA content in each cell, the COI region has sufficient variability to distinguish the majority of species among them (Biondo et al. 2016). This technique has been already employed to address the demand of assessing the actual identity and/or provenance of marketed products, as well as to unmask mislabelling and fraudulent substitutions, difficult to detect especially in manufactured seafood (Barbuto et al., 2010; Galimberti et al., 2013; Filonzi, Chiesa, Vaghi, & Nonnis Marzano, 2010). Nowadays,the research concerns the use of genetic markers to identify not only the species and/or varieties of fish, but also to identify molecular characters able to trace the origin and to provide an effective control tool forproducers and consumers as a supply chain in agreementwith local regulations.

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Tuna fishing is practiced on the Vietnamese coast between Nha-Trang, Phan-rang-and Bindh-dinh (Qui-nhon). This note is focused on the fishing techniques used in the mentioned area.