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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Mechanism of metallothionein gene regulation in tilapia.

January 2007 (has links)
Chan, Wai Lun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 140-157). / Abstracts in English and Chinese. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgements --- p.v / Table of Contents --- p.1 / List of Tables --- p.4 / List of Figures --- p.5 / List of Abbreviations --- p.8 / Chapter 1. --- Introduction --- p.10 / Chapter 1.1 --- Biology of metals --- p.10 / Chapter 1.2 --- Metal detoxification systems --- p.11 / Chapter 1.3 --- Metallothionein --- p.13 / Chapter 1.4 --- Classification of MTs --- p.15 / Chapter 1.5 --- Biological roles of MT --- p.15 / Chapter 1.5.1 --- Homeostasis of essential transition metal ion --- p.15 / Chapter 1.5.2 --- Detoxification of non-essential heavy metal ion --- p.17 / Chapter 1.5.3 --- Protection against oxidative stress --- p.18 / Chapter 1.5.4 --- Role in neurodegenerative diseases --- p.19 / Chapter 1.6 --- Molecular biology of MT --- p.19 / Chapter 1.6.1 --- MT gene structure --- p.19 / Chapter 1.6.2 --- MT gene regulation --- p.21 / Chapter 1.7 --- MRE binding transcription factor-1 (MTF-1) --- p.30 / Chapter 1.8 --- Activation of MTF-1 --- p.31 / Chapter 1.9 --- Target genes of MTF-1 --- p.32 / Chapter 1.10 --- Fish MT gene and MTF-1 --- p.33 / Chapter 1.11 --- Tilapia --- p.39 / Chapter 1.12 --- Study of tilapia MT --- p.41 / Chapter 1.13 --- Aims and rationale of study --- p.43 / Chapter 2. --- Materials and Methods --- p.45 / Chapter 2.1 --- Cloning of tilapia MT gene 5'-flanking region --- p.45 / Chapter 2.1.1 --- Animals --- p.45 / Chapter 2.1.2 --- Preparation of tilapia genomic DNA --- p.45 / Chapter 2.1.3 --- DNA walking --- p.45 / Chapter 2.1.4 --- Amplification of whole tiMT gene --- p.50 / Chapter 2.2 --- Determination of transcription start site --- p.51 / Chapter 2.2.1 --- Total RNA extraction --- p.51 / Chapter 2.2.2 --- Rapid amplification of 5,complementary DNA ends (5' RACE) --- p.52 / Chapter 2.3 --- Transient transfection assay --- p.54 / Chapter 2.3.1 --- Cell culture --- p.54 / Chapter 2.3.2 --- Construction of pGL3-tiMT deletion mutants --- p.54 / Chapter 2.3.3 --- Preparation of heavy metal solutions --- p.56 / Chapter 2.3.4 --- Determination of heavy metal ion toxicities by alamarBlue´ёØ assay --- p.56 / Chapter 2.3.5 --- Transient transfection of plasmids to Hepa-T1 cells --- p.56 / Chapter 2.3.6 --- Metal ions treatment and study of tiMT promoter activities --- p.57 / Chapter 2.3.7 --- Transient gene expression studies of deletion mutants of tiMT promoter --- p.57 / Chapter 2.4 --- Site-directed mutagenesis of tiMT promoter --- p.58 / Chapter 2.4.1 --- Polymerase chain reaction (PCR)-based site-directed mutagenesis --- p.58 / Chapter 2.4.2 --- Transient transfection of plasmids to Hepa-T1 cells and study of tiMT promoter activities --- p.62 / Chapter 2.5 --- Electrophoretic mobility shift assay (EMSA) --- p.63 / Chapter 2.5.1 --- Extract preparation --- p.63 / Chapter 2.5.2 --- Preparation of radiolabeled tiMRE oligonucleotides --- p.63 / Chapter 2.5.3 --- Electrophoretic mobility shift assay (EMSA) --- p.64 / Chapter 3. --- Results --- p.66 / Chapter 3.1 --- "Cloning of tilapia MT (tiMT) gene 5,-flanking region and amplification of whole tiMT gene" --- p.66 / Chapter 3.2 --- Determination of transcription start site --- p.69 / Chapter 3.3 --- Cloning of tiMT promoter fragment into reporter vector --- p.72 / Chapter 3.4 --- Determination of heavy metal ion toxicities by alamarBlue´ёØ assay --- p.72 / Chapter 3.5 --- Study of tiMT promoter activities by heavy metal ions exposure..… --- p.72 / Chapter 3.6 --- Cloning of deletion mutants of tiMT promoter --- p.79 / Chapter 3.7 --- Transient gene expression studies of deletion mutants of tiMT promoter --- p.80 / Chapter 3.8 --- Cloning of mutants with site-directed mutagenesis in tiMT promoter --- p.88 / Chapter 3.9 --- Site-directed mutagenesis of tiMT promoter --- p.92 / Chapter 3.10 --- Electrophoretic Mobility Shift Assay (EMSA) --- p.97 / Chapter 4. --- Discussion --- p.102 / Chapter 4.1 --- Tilapia MT gene --- p.102 / Chapter 4.2 --- Resistance of tilapia to heavy metal ions --- p.107 / Chapter 4.3 --- Functional analysis of tiMT gene promoter by transient transfection --- p.111 / Chapter 4.4 --- DNA binding of metal responsive transcription factor in Hepa-T1 cells --- p.121 / Chapter 4.5 --- Conclusion --- p.138 / References --- p.140
22

Total sulfur amino acid requirement and its application to practical diets for juvenile Tilapia (Oreochromis spp.)

Nguyen, Tri N., January 2007 (has links) (PDF)
Thesis (Ph.D.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 96-105)
23

A comparative study of the immunological properties of extracellular products between virulent and less virulent Edwardsiella tarda

Wiedenmayer, Alyssa Ann, Klesius, Phillip H. January 2006 (has links) (PDF)
Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references.
24

Imunomodulação por Actigen® em tilápia-do-nilo (Oreochromis niloticus): Respostas fisiológicas e desempenho produtivo após desafio com LPS

Ha, Natalia [UNESP] 02 March 2015 (has links) (PDF)
Made available in DSpace on 2015-08-20T17:10:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-03-02. Added 1 bitstream(s) on 2015-08-20T17:26:03Z : No. of bitstreams: 1 000843914.pdf: 1658836 bytes, checksum: 2abc2c67b74bfe3e90f08338f80c9efc (MD5) / Actigen® (ACT) é um prebiótico contendo frações ativas de mananoproteínas (FAMP) e devido ao seu papel na imunomodulação melhora o desempenho produtivo e a saúde intestinal. As frações ativas de mananoproteínas que são derivadas da parede celular e podem ser facilmente adicionados à dieta dos peixes. A sua administração nos sistemas de produção de peixes têm promovido melhores índices de desempenho além de compensar os efeitos indesejáveis do estresse, comuns na piscicultura. Os estudos dos efeitos da administração de FAMP em dietas para peixes ainda são recentes, principalmente com relação à padronização da forma de administração, dosagem e regime alimentar para cada espécie. O objetivo do presente trabalho foi avaliar os efeitos de diferentes concentrações de ACT sobre o desempenho zootécnico, respostas imunológicas e fisiológicas em tilápia-do-Nilo após desafio com o lipopolissacarídeo (LPS). O experimento foi realizado no Laboratório de Aquicultura da Unesp de Dracena, onde foram utilizados 288 juvenis de tilápias (12 animais/caixa) e foi conduzido em um delineamento inteiramente casualizado com 4 tratamentos (0%; 0,04%; 0,06% e 0,08% de ACT) e 6 repetições. Foram realizados dois experimento, sendo que no primeiro foram realizadas duas biometrias aos 30 e 60 dias de experimento, com coletas de amostras de sangue de dois peixes por caixa em cada período. O segundo experimento foi realizado após os 60 dias, no qual os peixes foram desafiados com injeção intraperitoneal com LPS e após 5 e 12 dias da inoculação, foram coletadas amostras sanguíneas de dois peixes por caixa. Foram avaliados o desempenho zootécnico, parâmetros imunológicos, hematológicos e bioquímicos. Os resultados obtidos foram submetidos à análise de variância (ANOVA) e as médias comparadas pelo teste de Tukey (5%), pelo programa estatístico SAS, versão 9.0. O uso de frações... / Actigen® is a prebiotic containing active fractions of mannan rich proteins and due to its role in immunomodulation improves growth performance and intestinal health. The active fractions of mannan rich proteins are derived from the cell wall of yeast Saccharomyces cerevisiae, easily added to the diet of fish, and their use in fish production systems has promoted better performance indices beyong compensating the common undesirable effects of stress in fish farming. Studies of the effects of active fractions of mannan rich proteins in diets for fish are still recent especially regard the standardization of administration route, dosage and diet for each species. The aim of this study was to evaluate the effects of different concentrations of ACT on the immune responses of livestock, physiological and performance of Nile tilapia after challenge with lipopolysaccharide (LPS). The experiment was carried out in the Aquaculture Laboratory of UNESP, Dracena, where 288 juvenile tilapia (12 animals/box) were used in a completely randomized design with 4 treatments (0%, 0.04%, 0.06% and 0.08% ACT) and 6 replications. Two experiments were conducted, in the first were two biometrics at 30 and 60 days of experiment, with collections of two fish blood samples per box in each period. The second experiment was carried out after 60 days, in which the fish were challenged by intraperitoneal injection with LPS and after 5 and 12 days after inoculation, blood samples were collected from two fish per box. The growth performance, immunological, hematological and biochemical parameters were measured. The results obtained were subjected to analysis of variance (ANOVA) and means compared by Tukey test (5%), using the statistical program SAS, version 9.0. The active fractions of mannan rich proteins administration showed some positive effects on the immune parameters, indicating a possible beneficial action in order to ...
25

Avaliação econômica e produtiva de tilápia do Nilo, revertida e não revertida, na fase de recria/

Squassoni, Gustavo Henrique. January 2010 (has links)
Orientador: Maria Célia Portella / Coorientador: Dalton José Carneiro / Banca: Cláudio Angelo Agostinho / Banca: Maria Inêz Espagnolli Geraldo Martins / Resumo: A piscicultura nacional passa por um momento delicado onde a maior preocupação é o mercado. O desenvolvimento deste setor produtivo depende de adaptações nos diferentes sistemas de produção adotados atualmente, sendo necessário adequar-se às restrições impostas pelo mercado, bem como analisar a viabilidade econômica de produções alternativas. O presente estudo teve como objetivo avaliar o desempenho produtivo e econômico da tilápia do Nilo durante a fase de recria, submetida ou não ao processo de reversão sexual, em três diferentes sistemas de cultivo: semi-intensivo com utilização de fertilização orgânica de viveiros, semi-intensivo com utilização de dieta formulada e sistema intensivo em hapas com oferecimento de dieta formulada. Utilizou-se um delineamento inteiramente casualizado, com seis tratamentos em esquema fatorial 3 x 2, referente aos três sistemas de produção e aos dois grupos de animais. Para a realização do experimento, foram utilizados 12.920 juvenis de tilápia do Nilo, com peso médio inicial de 0,3 g, distribuídos em 12 viveiros escavados e 6 hapas, na densidade de 20 e 600 peixes/m3, respectivamente. Não foram observadas diferenças no desempenho de peixes revertidos ou não revertidos. Os peixes dos tratamentos submetidos ao sistema semi-intensivo com dieta formulada apresentaram melhores (p<0,05) ganho em peso, conversão alimentar aparente e taxa de crescimento específico (42,3g; 1,17; 3,71%, respectivamente). Os itens de maior importância na participação dos custos totais foram os relacionados à aquisição de juvenis e alimentação, respectivamente. De maneira geral, o período desfavorável (inverno) e o custo elevado da ração utilizada (R$2,33/kg) proporcionaram prejuízos. Na simulação da produção, verificaram-se maiores lucros operacionais para os tratamentos semi-intensivos em viveiros com dieta formulada, com utilização... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The national aquaculture is currently in a period in which part of the market is changing. To be successful, the aquaculture should be able to adapt its production systems aiming at to adjust and meet the market restrictions. The new trends point to different possibilities of aquaculture production that potentially increase the incomes. The objective of this study was to evaluate the growth, economic performance and microbiological characteristics of Nile tilapia reared in different production systems during the initial growth phase. Specifically, mono and mixed-sex Nile tilapia juvenile were raised in three farming systems: semi-intensive using only organic fertilization (swine manure), semi-intensive using formulated diet, and intensive system in hapas using diet formulated. The experiment was developed in two factorial design (3 x 2); considering as factors, three production systems and two groups of fish submitted or not to the process of sex reversal. In the experiment, 12,920 Nile tilapia juvenile (initial weight 0.3g) were distributed into 12 ponds and 6 hapas at the densities of 20 and 600 fish/m3, respectively. There were no differences of growth performance of the mono or mixed-sex fish. The fish subjected to semiintensive system with formulated diet have shown better (p <0.05) weight gain, feed conversion ratio and specific growth rate (42.3 g, 1.17 and 3.71%, respectively). The items of highest importance in the composition of the total costs were related to the acquisition of juveniles and feed, respectively. In general, the unfavorable period (winter) and the high cost of the feed used (R$ 2.33 / kg) resulted in losses. In the analysis of the production simulation, the treatments with mono-sex tilapia in semi-intensive ponds fed with formulated diet resulted in higher operating profits, due to the higher survival rates and growth observed in this group... (Complete abstract click electronic access below) / Mestre
26

Imunomodulação por Actigen® em tilápia-do-nilo (Oreochromis niloticus): Respostas fisiológicas e desempenho produtivo após desafio com LPS /

Ha, Natalia. January 2015 (has links)
Orientador: Leonardo Susumu Takahashi / Co-orientador: Jaqueline Dalbello Biller Takahashi / Banca: Urbano dos Santos Ruiz / Banca: Fabiana Pilarski / Resumo: Actigen® (ACT) é um prebiótico contendo frações ativas de mananoproteínas (FAMP) e devido ao seu papel na imunomodulação melhora o desempenho produtivo e a saúde intestinal. As frações ativas de mananoproteínas que são derivadas da parede celular e podem ser facilmente adicionados à dieta dos peixes. A sua administração nos sistemas de produção de peixes têm promovido melhores índices de desempenho além de compensar os efeitos indesejáveis do estresse, comuns na piscicultura. Os estudos dos efeitos da administração de FAMP em dietas para peixes ainda são recentes, principalmente com relação à padronização da forma de administração, dosagem e regime alimentar para cada espécie. O objetivo do presente trabalho foi avaliar os efeitos de diferentes concentrações de ACT sobre o desempenho zootécnico, respostas imunológicas e fisiológicas em tilápia-do-Nilo após desafio com o lipopolissacarídeo (LPS). O experimento foi realizado no Laboratório de Aquicultura da Unesp de Dracena, onde foram utilizados 288 juvenis de tilápias (12 animais/caixa) e foi conduzido em um delineamento inteiramente casualizado com 4 tratamentos (0%; 0,04%; 0,06% e 0,08% de ACT) e 6 repetições. Foram realizados dois experimento, sendo que no primeiro foram realizadas duas biometrias aos 30 e 60 dias de experimento, com coletas de amostras de sangue de dois peixes por caixa em cada período. O segundo experimento foi realizado após os 60 dias, no qual os peixes foram desafiados com injeção intraperitoneal com LPS e após 5 e 12 dias da inoculação, foram coletadas amostras sanguíneas de dois peixes por caixa. Foram avaliados o desempenho zootécnico, parâmetros imunológicos, hematológicos e bioquímicos. Os resultados obtidos foram submetidos à análise de variância (ANOVA) e as médias comparadas pelo teste de Tukey (5%), pelo programa estatístico SAS, versão 9.0. O uso de frações... / Abstract: Actigen® is a prebiotic containing active fractions of mannan rich proteins and due to its role in immunomodulation improves growth performance and intestinal health. The active fractions of mannan rich proteins are derived from the cell wall of yeast Saccharomyces cerevisiae, easily added to the diet of fish, and their use in fish production systems has promoted better performance indices beyong compensating the common undesirable effects of stress in fish farming. Studies of the effects of active fractions of mannan rich proteins in diets for fish are still recent especially regard the standardization of administration route, dosage and diet for each species. The aim of this study was to evaluate the effects of different concentrations of ACT on the immune responses of livestock, physiological and performance of Nile tilapia after challenge with lipopolysaccharide (LPS). The experiment was carried out in the Aquaculture Laboratory of UNESP, Dracena, where 288 juvenile tilapia (12 animals/box) were used in a completely randomized design with 4 treatments (0%, 0.04%, 0.06% and 0.08% ACT) and 6 replications. Two experiments were conducted, in the first were two biometrics at 30 and 60 days of experiment, with collections of two fish blood samples per box in each period. The second experiment was carried out after 60 days, in which the fish were challenged by intraperitoneal injection with LPS and after 5 and 12 days after inoculation, blood samples were collected from two fish per box. The growth performance, immunological, hematological and biochemical parameters were measured. The results obtained were subjected to analysis of variance (ANOVA) and means compared by Tukey test (5%), using the statistical program SAS, version 9.0. The active fractions of mannan rich proteins administration showed some positive effects on the immune parameters, indicating a possible beneficial action in order to ... / Mestre
27

Avaliação econômica e produtiva de tilápia do Nilo, revertida e não revertida, na fase de recria

Squassoni, Gustavo Henrique [UNESP] 09 June 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-06-09Bitstream added on 2014-06-13T18:56:20Z : No. of bitstreams: 1 squassoni_gh_me_jabo.pdf: 417643 bytes, checksum: 2b7f2ef0b5e020632b1db1603aa276ca (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A piscicultura nacional passa por um momento delicado onde a maior preocupação é o mercado. O desenvolvimento deste setor produtivo depende de adaptações nos diferentes sistemas de produção adotados atualmente, sendo necessário adequar-se às restrições impostas pelo mercado, bem como analisar a viabilidade econômica de produções alternativas. O presente estudo teve como objetivo avaliar o desempenho produtivo e econômico da tilápia do Nilo durante a fase de recria, submetida ou não ao processo de reversão sexual, em três diferentes sistemas de cultivo: semi-intensivo com utilização de fertilização orgânica de viveiros, semi-intensivo com utilização de dieta formulada e sistema intensivo em hapas com oferecimento de dieta formulada. Utilizou-se um delineamento inteiramente casualizado, com seis tratamentos em esquema fatorial 3 x 2, referente aos três sistemas de produção e aos dois grupos de animais. Para a realização do experimento, foram utilizados 12.920 juvenis de tilápia do Nilo, com peso médio inicial de 0,3 g, distribuídos em 12 viveiros escavados e 6 hapas, na densidade de 20 e 600 peixes/m3, respectivamente. Não foram observadas diferenças no desempenho de peixes revertidos ou não revertidos. Os peixes dos tratamentos submetidos ao sistema semi-intensivo com dieta formulada apresentaram melhores (p<0,05) ganho em peso, conversão alimentar aparente e taxa de crescimento específico (42,3g; 1,17; 3,71%, respectivamente). Os itens de maior importância na participação dos custos totais foram os relacionados à aquisição de juvenis e alimentação, respectivamente. De maneira geral, o período desfavorável (inverno) e o custo elevado da ração utilizada (R$2,33/kg) proporcionaram prejuízos. Na simulação da produção, verificaram-se maiores lucros operacionais para os tratamentos semi-intensivos em viveiros com dieta formulada, com utilização... / The national aquaculture is currently in a period in which part of the market is changing. To be successful, the aquaculture should be able to adapt its production systems aiming at to adjust and meet the market restrictions. The new trends point to different possibilities of aquaculture production that potentially increase the incomes. The objective of this study was to evaluate the growth, economic performance and microbiological characteristics of Nile tilapia reared in different production systems during the initial growth phase. Specifically, mono and mixed-sex Nile tilapia juvenile were raised in three farming systems: semi-intensive using only organic fertilization (swine manure), semi-intensive using formulated diet, and intensive system in hapas using diet formulated. The experiment was developed in two factorial design (3 x 2); considering as factors, three production systems and two groups of fish submitted or not to the process of sex reversal. In the experiment, 12,920 Nile tilapia juvenile (initial weight 0.3g) were distributed into 12 ponds and 6 hapas at the densities of 20 and 600 fish/m3, respectively. There were no differences of growth performance of the mono or mixed-sex fish. The fish subjected to semiintensive system with formulated diet have shown better (p <0.05) weight gain, feed conversion ratio and specific growth rate (42.3 g, 1.17 and 3.71%, respectively). The items of highest importance in the composition of the total costs were related to the acquisition of juveniles and feed, respectively. In general, the unfavorable period (winter) and the high cost of the feed used (R$ 2.33 / kg) resulted in losses. In the analysis of the production simulation, the treatments with mono-sex tilapia in semi-intensive ponds fed with formulated diet resulted in higher operating profits, due to the higher survival rates and growth observed in this group... (Complete abstract click electronic access below)
28

Caracterização de indivíduos hesitantes e ousados na tilápia-do-Nilo /

Silva, Graziela Valença da. January 2010 (has links)
Orientador: Gilson Luiz Volpato / Banca: Eleonora Trajano / Banca: Rodrigo Egydio Barreto / Resumo: Nos identificamos percentuais de individuos que se distribuem no continuo hesitayaoousadia na tihipia-do-Nilo, Oreochromis niloticus (Linnaeus, 1758). Avaliamos a reayao de peixes isolados (100 peixes, 22.1 ± 5.9 g) a urn objeto-estimulo introduzido subitamente no aquario. Dividimos a parede frontal do aquario em quatm regioes iguais, atraves de linhas externas verticais. Apos isolamento por 24 h nesse aquario, assim que o peixe estava numa das duas extremidades, introduziamos subitamente 0 objetoestimulo (cilindro de PVC de 10 em diametro) na extremidade oposta (~ 30 em do peixe). Nos 5 min seguintes registravamos: a) tempo para sair da regiao inicial; b) tempo para chegar a regiao do objeto-estimulo; e c) tempo em locomoyao. Identificamos dois perfis extremos de resposta: permanencia na regiao inicial (peixes hesitantes) e aproximayao do objeto-estimulo em ate 40 s (peixes ousados). Este criterio resultou em 20% de individuos hesitantes, 29% de ousados e 51% de intermediarios, sendo os peixes ousados os mais ativos. Esses perfIS nao tiveram associayao com 0 sexo dos animais. Para testar a associayao dos perfis hesitante e ousado com a agressividade, uma nova amostra de peixes foi avaliada (115 peixes) como descrito acima, porem 24h horas depois urn segundo teste foi realizado, mas com outro objeto-estimulo introduzido no aquario. Os peixes considerados hesitantes ou ousados nos dois testes consecutivos foram submetidos a anaIise da agressividade. Esta foi avaliada atraves do teste do espelho (20 peixes de cada perfil) e pareamento entre coespecificos (10 duplas de cada perfil). Os peixes ousados foram mais agressivos que os hesitantes. Em urn terceiro estudo, esses peixes foram submetidos a estresse de confinamento por 30 min e o estresse foi avaliado pe1a mudanya na frequencia ventilatoria e colorayao do olho. Peixes ousados foram mais responsivos ao estresse. Conc1uimos que os perfis hesitante e ousado ocorrem na tilápia-do-Nilo, .... / Abstract: We identified percentage of fish III the shy-bold continuum III the Nile tilapia, Oreochromis niloticus (Linnaeus, 1758). This was achieved from the reaction of isolated fish (100 fish, 22.1 ± 5.9 g) to a stimulus-object suddenly introduced into the aquarium. The frontal glass of the test aquarium was divided in four regions of same area by vertical lines outside the aquaria. After 24-h isolation in the test aquarium, when the fish was in one of the extremities of the aquarium, the stimulus-object (1O-cm diameter PVC cylinder) was suddenly immersed into the aquarium in the opposite side (- 30 cm from the fish). We registered in the next 5 min: a) latency to the fish exit from the initial area; b) time to reach the stimulus-object area; and c) time spent in locomotion. We could identify two extreme responses: staying in the initial area (fish considered shy) and approaching the stimulus-object in up to 40 s (bold fish). This criterion resulted in 20% shy, 29% bold and 51% intermediate fish, with the bold fish being more active. These profiles were not associated with fish sex. To test the association of shy and bold fish with aggression, these fish were identified in other sample (115 fish) as described above; 24 h later a second test was performed (but now with another object introduced). Fish considered shy or bold in these two consecutive testes were then tested for aggression. Aggression was evaluated by the mirror test (20 fish each profile) and also pairing with conspecific fish (10 pairs in each profile). Bold fish were more aggressive than the shy fish. In a third study, these fish were subjected to stress confinement for 30 min and stress evaluated in terms of changes in ventilation rate and eye color. Bold fish were the most responsive to stress. In conclusion, shy and bold profiles occur in the Nile tilapia, can be identified by reaction to a sudden stimulus and ... / Mestre
29

Effects of sublethal concentrations of pesticides on tropical freshwater fish quality

Perez-Camargo, Gerardo January 1995 (has links)
No description available.
30

Copper uptake and toxicity in tilapia Oreochromis niloticus exposed to copper sulphate

Bell, Thomas Allen January 1996 (has links)
The copper uptake and toxicity of young and market-size tilapia, Oreochromis niloticus, exposed to copper sulP'hate were investigated. A series of preliminary experiments were conducted to provide requisite information for the final experiment. Preliminary experiments established uptake by the culture systems, feed and/or faeces, and. the impact of fish nutritional state on uptake. Other experiments established the median lethal concentration of copper to this species, an extrapolated minimal lethal concentration, and the optimum exposure duration and concentration for copper uptake. The remaining preliminary experiments defined the relationship between toxicity and uptake in small compared to market-size tilapia, and between muscle location (within the fillet) and copper uptake. The final experiment established the amount of copper uptake in the edible tissue of market-size tilapia after a worst-case exposure to copper sulphate. The worst-case was defined as the maximum non-lethal concentration for a period significantly exceeding that encountered in commercial production systems. The worst-case experiment comprised market-size fish (350 to 570 g) being exposed at a nominal concentration of 365 ppb copper for nine days. This study demonstrated that copper did not accumulate in the edible tissue of tilapia above that measured in non-exposed control fish. A mean level of copper in the edible muscle of non-exposed fish, as measured by atomic absorption spectometry, was 2.14 pprn (dry page weight basis), while in fish exposed to a nominal concentration of 365 ppb of copper it was found to be 2.31 ppm. These data are suitable for incorporation into a United States Food and Drug Administration, New Animal Drug Approval application for the approval of copper sulphate use as a drug for aquatic species.

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