Thesis (M. S. - Renewable Natural Resources & Wildlife and Fisheries Science.)--University of Arizona, 1997. / Includes bibliographical references (leaves 138-144).

Electrofishing is a sampling tool commonly used by fisheries researchers. While much is known about the effects of electroshock on fish physiology, consequences to the immune system and disease progression have not received attention. To understand the effects of electroshock on immune function we undertook a comparison of electroshock and handling stress in regards to selected immune functions and disease progression in juvenile spring chinook salmon (Oncorhynchus tshawytscha). The handling stress treatment was included to insure the responsiveness of the fish. Our objectives were to determine the effects of electroshock on immune function, determine the mechanism of any observed alteration, and to determine the effects of electroshock on disease progression. Skin mucous lysozyme concentrations were not affected by exposure to electroshock. Respiratory burst activity may be enhanced in leukocytes immediately after an in vitro electroshock. Any effect in vivo, however, appears to be brief given the lack of differences observed 3 h after exposure. The specific immune response, measured as the ability of anterior kidney leukocytes to generate antibody producing cells (APC), was suppressed 3 h after electroshock, but recovered within 24 h. This response was similar in timing and magnitude to that of fish subjected to an acute handling stress. The mechanism of suppression is hypothesized to be via elevation of plasma cortisol concentrations. The ability to generate APC may be suppressed 7 d after electroshock, but it is not evident what mechanism is responsible for this suppression. There was some evidence that the progression of a Renibacterium salmoninarum (RS) infection was altered after exposure to an electroshock. Exposure to electroshock did not have a clear affect on the severity of infection or the number of mortalities, but may have accelerated the time to death in infected fish that died. The limited duration of specific immune suppression and lack of effect on mortality in RS infected fish lead us to conclude that electrofishing under the conditions we tested is a safe procedure in regards to immunity and disease. / Graduation date: 2000

Thesis (M.S.), Natural Resources / Fisheries, University of Wisconsin--Stevens Point, 2004. / Includes bibliographical references (leaves 53-58).

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Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains vii, 65 p. : ill., maps (part col.). Includes abstract. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains vi, 97 p. : ill., maps. Includes abstract. Includes bibliographical references.

Made available in DSpace on 2016-08-10T10:44:55Z (GMT). No. of bitstreams: 1 NICELLY BRAUDES ARAUJO.pdf: 459324 bytes, checksum: 86c3d7c381647de67fdebaa900b6869a (MD5) Previous issue date: 2006-09-25 / The Ribeirão Ouvidor basin is located in the Southeast of the State of Goiás. This stream is formed by the junction of the Taquara I and Taquara II streams and belongs to the Paranaíba River basin, high Paraná River basin. This study aims to describe the fish assemblage using ecological descriptors and to determine the fish-environment interaction considering ten environmental parameters (presence of environmental impacts, channel substrate, water temperature, dissolved oxygen, pH, conductivity, turbidity, luminosity, water flow velocity, and channel width). Fish sampling and measurement of environmental parameters were carried out from August/2004 to June/2005) in a stretch 50m long of nine tributaries and in the main channel of the Ribeirão Ouvidor. Fishes were collected using electric fishing equipment. Four thousand forty-nine individuals were collected, reaching the saturation of species with a total richness of 35 species, from which 42.8% are constant in the sampled watercourses. The richness, diversity (Shannon-Wiener) and uniformity are highest in courses with greater water volume, as the Ribeirão Ouvidor, than in streams. This result was corroborated by the rarefaction analysis. The multivariate analysis of Co-inertia indicates that of the ten environmental parameters considered, the water flow velocity, channel width, pH and water temperature structure the fish assemblage. The interaction of the water flow velocity and channel width with the ichthyofauna is influenced by the anthropogenic activities, while that involving pH and water temperature is influenced by the regional seasonality. / A bacia do Ribeirão Ouvidor está localizada no sudeste do estado de Goiás. O ribeirão nasce da junção dos córregos Taquara I e Taquara II e deságua no rio Paranaíba, pertencendo assim, à bacia do rio Paraná. Este estudo tem como objetivo descrever ecologicamente a comunidade ictiofaunística e determinar a interação peixe-ambiente considerando dez parâmetros ambientais (presença de impactos ambientais, substrato da calha, temperatura da água, oxigênio dissolvido, pH, condutividade, turbidez, luminosidade, velocidade da água e largura da calha). As amostragens da ictiofauna e dos parâmetros ambientais foram realizadas bimestralmente (de Agosto/2004 a Junho/2005) num trecho de 50m de comprimento de nove afluentes e na calha principal do Ribeirão Ouvidor. A coleta dos peixes foi realizada utilizando-se a pesca elétrica. Foram coletados 4049 indivíduos, a saturação de espécies foi atinginda com uma riqueza total de 35 espécies, das quais 42,8% são constantes nos locais amostrados. A riqueza, diversidade (Shannon-Wiener) e uniformidade são maiores em cursos com maior volume de água, como o Ribeirão Ouvidor, que em córregos, resultado este corroborado pela análise de rarefação. A análise multivariada de Co-inércia indica que dos dez parâmetros ambientais considerados, a velocidade da água, largura da calha, pH e temperatura da água estruturam as assembléias de peixes. A interação da velocidade da água e largura da calha com a ictiofauna é influenciada pelas atividades antropogênicas, enquanto que as variáveis pH e temperatura tem influência da escala temporal regional.

Made available in DSpace on 2016-08-10T10:45:10Z (GMT). No. of bitstreams: 1 ALESANDRA MARTINS DIAS.pdf: 2070475 bytes, checksum: 9cb727e03fa9ee325a8c09b309b99cb5 (MD5) Previous issue date: 2008-08-18 / This study was conducted in the basin of the João Leite River, which integrates the high Paraná River basin in the southwest of the Goiás State. This river has origin in the Ouro Verde county and it empties in the Meia Ponte River, its basin shelter about 1.600.000 inhabitants distributed in seven counties. The weather is classified as hot and sub-humid with four or five dry months. The predominant covering vegetation is the Cerrado, a savanna vegetation type. This study aims to i) compare the fish assemblages of four creeks located into a conservation unit (Altamiro de Moura Pacheco Ecological State Park) with this of six creeks presents in not preserved areas in the same basin; and ii) determine the fish-environment interaction considering 24 creeks of the sub-basin of the River João Leite. Fish sampling was carried through in the low water period using electric fishing in stretches of 50m, where the environmental parameters were measured with portable equipment (pH, conductivity, turbidity) and through satellite s images (size of the drainage, grazing, urban and covering vegetation areas). The comparison of fish assemblages was given through a cluster analysis followed by a Morisita-Horn index, and the quality of the aquatic environment was evaluated by the method of ABC curves , whereas the relation fish-environment was determined by multiple regression analysis, method stepwise. The preserved creeks present a richness average bigger than this in creeks not preserved, but in both the assemblages suffer influence of natural or anthropogenic disturbances. The multiple regression analysis indicates that of the seven parameters analyzed, only the pH and covering vegetation of the basin structure the ichthyofauna of the creeks and is related to the changes of the landscape of anthropic origin in this studied basin. / A sub-bacia do ribeirão João Leite faz parte do alto da bacia do rio Paraná no sudoeste do estado de Goiás. Este ribeirão nasce no município de Ouro Verde e deságua no rio Meia Ponte, abrigando cerca de 1.600.000 habitantes distribuídos em sete municípios goianos. Este estudo objetiva: i) comparar a ictiofauna de quatro riachos localizados numa unidade de conservação (Parque Ecológico Altamiro de Moura Pacheco) com a de seis riachos presentes em áreas não preservadas da bacia em estudo e ii) determinar a interação peixe-ambiente considerando sete parâmetros ambientais em 24 riachos da sub-bacia do ribeirão João Leite. A coleta da ictiofauna foi realizada no período da estiagem utilizando-se a pesca elétrica em trechos de 50 m, sendo que os parâmetros ambientais foram medidos com equipamentos portáteis (pH, condutividade, turbidez) e através de imagens de satélite (tamanho da área de drenagem, de pastagens, solo exposto ou áreas urbanas e da cobertura vegetal). A comparação da ictiofauna deu-se através de uma análise de agrupamento seguida de um índice de Morisita-Horn. A qualidade do ambiente aquático foi avaliada utilizando-se o método de curvas ABC , enquanto que a relação peixe-ambiente foi determinada através de uma análise de regressão múltipla tipo stepwise. Os riachos preservados apresentam a média da riqueza maior do que esta em riachos não preservados, porém em ambos os casos as assembléias sofrem influência de perturbações naturais ou antropogênicas. A análise multivariada de regressão indica que dos sete parâmetros analisados, somente o pH e cobertura vegetal da bacia estruturam a ictiofauna do ribeirão João Leite e estão relacionadas às modificações da paisagem de origem antrópica presentes na bacia em estudo.