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Made available in DSpace on 2014-06-11T19:22:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-10Bitstream added on 2014-06-13T19:27:36Z : No. of bitstreams: 1 urbinati_ec_me_jabo.pdf: 438124 bytes, checksum: ec3f06e377e44a119086563d92e6f440 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os relatos de produtores e pesquisadores sobre problemas na fase de ovulação do pacu Piaractus mesopotamicus durante a reprodução artificial nos conduziu a avaliar o uso da prostaglandina F2α. O estudo foi realizado em duas estações reprodutivas (2009/2010 e 2010/2011), com dois experimentos na estação 2009/2010 (T1 e T2) um experimento na estação 2010/2011 (T3). Foi amostrado um total de 45 fêmeas. As fêmeas do grupo controle foram induzidas apenas com extrato bruto de hipófise de carpa (EC, 6mg/kg), enquanto as do grupo tratado receberam prostaglandina F2α (PGF - 2ml/fêmea na estação 2009/2010 e 5ml/fêmea na estação 2010/2011), além da dose de EC. Nas duas estações observou-se 100% de fêmeas desovadas no grupo tratado com PGF enquanto no grupo controle a desova ocorreu em 52,94% e 83,33% no primeiro e segundo experimentos da estação 2009/2010, respectivamente. Em 2010/2011, somente 25% das fêmeas controle desovaram. As taxas de fecundidade, fertilização e eclosão não diferiram (p>0,05) entre os grupos de fêmeas. A análise da freqüência de volume de ovócitos nas diferentes fases de desenvolvimento mostrou, nos ovários analisados pós-desova, valores significativamente maiores (p<0,05) de ovócitos vitelogênicos com quebra de vesícula germinativa, mas não ovulados no grupo controle e maior ocorrência de ovócitos pré-vitelogênicos no grupo tratado com PGF. Independente do tratamento, as maiores taxas de fertilidade ocorreram ao redor de 275 UTA, enquanto a maior parte das fêmeas desovou entre 276 e 323 UTA. Do mesmo modo, independente do tratamento, houve um decréscimo significativo (p<0,05) nas taxas de fertilização e eclosão na comparação das duas coletas de 2009/2010. Os dados obtidos neste estudo sugerem que a prostaglandina pode aumentar as taxas de desova em fêmeas de pacu induzidas à reprodução, com efeito evidente na liberação dos ovócitos dos folículos / Due to reports of fish farmers and researchers about the problems in the ovulation phase of P. mesopotamicus during its artificial reproduction we evaluated the use of prostaglandin F. The study was conducted in two spawning seasons (2009/2010 and 2010/2011), with two sampling in season 2009/2010 and one sampling in 2010/2011. Forty five females broodstock were sampled. Control group was injected with carp pituitary extract (CE, 6mg/kg), while treated group received prostaglandin F (PGF – 2ml/ 2009/2010 season and 5ml/2010/2011 season) in addiction to CE. In the two seasons 100% of treated with PGF groups spawned while in control groups 52,94% and 83,33% in first and second sampling of season 2009/2010 spawned, respectively. In 2010/2011 only 25% of control group spawned. Fecundity, fertility and hatching rates did not differ (p>0.05) between groups. The oocytes volume frequency analysis showed that in ovaries after spawning, in control group, there was a significant higher number (p<0.05) of vitelogenic oocytes with GVBD but anovulated, while in PGF treated group, a higher number (p<0.05) of pre-vitelogenic oocytes was observed. Independent on the treatment, the highest fertility rate occurred around 275 ATU, while most of the females spawned in a range of 276 and 323 ATU. The same way, independent on the treatment, there was a significant decrease (p<0.05) in fertility and hatching rates comparing samplings from 2009/2010. Data obtained in this study suggest that prostaglandin F might enhance spawning rate in hormonal induced females of pacu, with a notable effect on the release of oocytes from the follicles

Thesis (Ph. D. (Physiology)) -- University of Limpopo, 1993 / Refer to document

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Numerous natural and anthropogenic chemicals interact with endocrine systems of animals. The most widely studied of these endocrine active chemicals (EACs) are estrogen receptor agonists and antagonists. Because of the many important roles of estrogens in animals, xenoestrogens have the potential to impact environmental health. It has been proposed that xenoestrogen contaminants are responsible for recent increases in estrogen dependent human diseases and sexual and developmental abnormalities in wildlife. Aquatic species are particularly susceptible to persistent EACs that accumulate in sediments and biomagnify along trophic levels. Rainbow trout, Oncorhynchus mykiss, commonly used in biomedical research and as a sentinel species, was chosen as a model for studying mechanisms of xenoestrogen activity. The aims of this research were to assess the estrogenic activity of individual persistent, organic contaminants and simple mixtures in vivo. Emphasis was placed on determining the potential for xenoestrogens to alter sexual development or to induce sexually dimorphic biochemical responses. Gonadal abnormalities in trout exposed as embryos to the xenoestrogen o,p'-DDE showed that xenobiotics can affect trout sexual development. However, the absence of endocrine disruption by low doses of o,p'-DDE, by the xenoestrogens chlordecone and octylphenol, or by the anti-androgen p,p'-DDE, suggested that lethality is likely to precede endocrine disruption in highly exposed, feral salmonid populations. Sexually distinct responses in immature trout were documented with respect to vitellogenin induction (2 to 4 fold higher in females) and cytochrome P450 expression. Sex differences occurred only when doses of estrogens or xenoestrogens were below levels that cause maximal estrogenic responses. Evidence suggests that estrogen regulation may be fundamentally different in immature males and females, which may have implications for natural populations exposed to xenoestrogens. Vitellogenin induction and P450 modulation were responsive to mixtures of estrogens and xenoestrogens in a manner suggestive of additive activation of estrogen receptors. Cytochrome P450 dependent induction of lauric acid hydroxylation was observed for the first time in trout, in response to tamoxifen and mixtures of tamoxifen and 17��-estradiol. The estrogenic activity of tamoxifen and 4-hydroxy-2',4',6'-trichlorobiphenyl were greater in vivo than what was predicted by in vitro studies, which emphasized the need for mechanism based investigations of xenoestrogens in whole organisms. / Graduation date: 1999

Made available in DSpace on 2014-06-11T19:30:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-28Bitstream added on 2014-06-13T20:21:09Z : No. of bitstreams: 1 souza_be_dr_jabo.pdf: 1123725 bytes, checksum: 4cebbdbdb1129041b82e90f8aa6e56f1 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Foi avaliado como as dietas protéicas podem afetar os índices reprodutivos (fertilização e eclosão) e a característica seminal do pacu, Piaractus mesopotamicus criados em tanques-rede. Duzentos e vinte e quatro reprodutores com quatro anos de idade, peso e comprimento médios de 2,62 ± 0,59 Kg e 47,64 ± 2,83 cm respectivamente, foram distribuídos em 16 tanques-rede (5 m³/cada) na proporção de sete machos e sete fêmeas, com densidade de 2,8 peixes m-3 por tanque. Foi utilizado um delineamento experimental inteiramente casualizado, com quatro tratamentos e quatro repetições, sendo os tratamentos (T) constituídos por quatro rações experimentais extrusadas com diferentes níveis de proteína bruta (PB, %): T1 = 18; T2 = 24; T3 = 30 e T4 = 36, isoenergéticas (3.300 kcal kg-1 de ração), isocálcicas e isofosfóricas. Os peixes receberam as rações experimentais pelos seis meses que antecederam o período reprodutivo e, em seguida, foram selecionados a cada dois dias, dois machos e uma fêmea de cada tratamento totalizando-se 12 peixes, pelo período de 22 dias. Os reprodutores foram induzidos hormonalmente, aplicando-se duas doses de extrato bruto de pituitária de carpa totalizando 2,75 e 5,5 mg kg-1 para machos e fêmeas, respectivamente e após um período de 240 horas-grau seus gametas foram coletados e analisados. Nas condições do experimento, os reprodutores de pacu, Piaractus mesopotamicus atingiram à maturação gonadal nas quatro dietas utilizadas, entretanto, os valores dos índices reprodutivos (taxas de fertilização e eclosão) foram inferiores ao recomendado para a produção comercial. Todavia, as características seminais apresentaram diferenças significativas entre as quatro dietas estudadas, recomendandose a ração com 18% PB / Was evaluated how protein diets can affect reproductive rates (fertilization and hatching) and seminal characteristics of pacu, Piaractus mesopotamicus reared in cages. Two hundred and twenty-four breeding with four years of age, weight and average length of 2.62 ± 0.59 kg and 47.64 ± 2.83 cm respectively, were distributed in 16 cages (5 m³ / each) in the proportion seven males and seven females, with a density of 2.8 m-3 fish per tank. We used a experimental design completely randomized, composed by four treatments and four replicates, where the treatments (T) wore composed by four extruded experimental diets with different levels of crude protein (CP, %): T1 = 18; T2 = 24; T3 = 30 e T4 = 36, isoenergetic, (3.300 kcal kg-1 of diets), isocalcium and isophosphoric. Fish received the experimental diets for six months before the reproductive period then were selected every two days, two males and one female from each treatment in a total of 12 fish, for a period of 22 days. The breeding wore hormonally induced through two doses of crude extract of pituitary carp totaling 2,75 e 5,5 mg kg-1 for males and females, respectively, and after a period of 240 hoursdegree their gametes were collected and analyzed. Under the conditions of the experiment, the breeding of pacu, Piaractus mesopotamicus reached the gonadal maturation in the four diets, however, the values of reproductive indices (fertilization and hatching) were lower than recommended for commercial production. However, seminal characteristics showed significant differences among the four diets, recommending a diet with 18% CP

Orientador: Sérgio Ricardo Batlouni / Banca: Renata Guimarães Moreira / Banca: José Augusto Senhorini / Resumo: Os relatos de produtores e pesquisadores sobre problemas na fase de ovulação do pacu Piaractus mesopotamicus durante a reprodução artificial nos conduziu a avaliar o uso da prostaglandina F2α. O estudo foi realizado em duas estações reprodutivas (2009/2010 e 2010/2011), com dois experimentos na estação 2009/2010 (T1 e T2) um experimento na estação 2010/2011 (T3). Foi amostrado um total de 45 fêmeas. As fêmeas do grupo controle foram induzidas apenas com extrato bruto de hipófise de carpa (EC, 6mg/kg), enquanto as do grupo tratado receberam prostaglandina F2α (PGF - 2ml/fêmea na estação 2009/2010 e 5ml/fêmea na estação 2010/2011), além da dose de EC. Nas duas estações observou-se 100% de fêmeas desovadas no grupo tratado com PGF enquanto no grupo controle a desova ocorreu em 52,94% e 83,33% no primeiro e segundo experimentos da estação 2009/2010, respectivamente. Em 2010/2011, somente 25% das fêmeas controle desovaram. As taxas de fecundidade, fertilização e eclosão não diferiram (p>0,05) entre os grupos de fêmeas. A análise da freqüência de volume de ovócitos nas diferentes fases de desenvolvimento mostrou, nos ovários analisados pós-desova, valores significativamente maiores (p<0,05) de ovócitos vitelogênicos com quebra de vesícula germinativa, mas não ovulados no grupo controle e maior ocorrência de ovócitos pré-vitelogênicos no grupo tratado com PGF. Independente do tratamento, as maiores taxas de fertilidade ocorreram ao redor de 275 UTA, enquanto a maior parte das fêmeas desovou entre 276 e 323 UTA. Do mesmo modo, independente do tratamento, houve um decréscimo significativo (p<0,05) nas taxas de fertilização e eclosão na comparação das duas coletas de 2009/2010. Os dados obtidos neste estudo sugerem que a prostaglandina pode aumentar as taxas de desova em fêmeas de pacu induzidas à reprodução, com efeito evidente na liberação dos ovócitos dos folículos / Abstract: Due to reports of fish farmers and researchers about the problems in the ovulation phase of P. mesopotamicus during its artificial reproduction we evaluated the use of prostaglandin F. The study was conducted in two spawning seasons (2009/2010 and 2010/2011), with two sampling in season 2009/2010 and one sampling in 2010/2011. Forty five females broodstock were sampled. Control group was injected with carp pituitary extract (CE, 6mg/kg), while treated group received prostaglandin F (PGF - 2ml/ 2009/2010 season and 5ml/2010/2011 season) in addiction to CE. In the two seasons 100% of treated with PGF groups spawned while in control groups 52,94% and 83,33% in first and second sampling of season 2009/2010 spawned, respectively. In 2010/2011 only 25% of control group spawned. Fecundity, fertility and hatching rates did not differ (p>0.05) between groups. The oocytes volume frequency analysis showed that in ovaries after spawning, in control group, there was a significant higher number (p<0.05) of vitelogenic oocytes with GVBD but anovulated, while in PGF treated group, a higher number (p<0.05) of pre-vitelogenic oocytes was observed. Independent on the treatment, the highest fertility rate occurred around 275 ATU, while most of the females spawned in a range of 276 and 323 ATU. The same way, independent on the treatment, there was a significant decrease (p<0.05) in fertility and hatching rates comparing samplings from 2009/2010. Data obtained in this study suggest that prostaglandin F might enhance spawning rate in hormonal induced females of pacu, with a notable effect on the release of oocytes from the follicles / Mestre

Orientador: Elizabeth Romagosa / Coorientador: Wilson Rogério Boscolo / Banca: Alexandre Ninhaues da Silveira / Banca: Eduardo Medeiros Ferraz / Banca: Sérgio Ricardo Batlouni / Banca: Denilson Burkert / Resumo: Foi avaliado como as dietas protéicas podem afetar os índices reprodutivos (fertilização e eclosão) e a característica seminal do pacu, Piaractus mesopotamicus criados em tanques-rede. Duzentos e vinte e quatro reprodutores com quatro anos de idade, peso e comprimento médios de 2,62 ± 0,59 Kg e 47,64 ± 2,83 cm respectivamente, foram distribuídos em 16 tanques-rede (5 m³/cada) na proporção de sete machos e sete fêmeas, com densidade de 2,8 peixes m-3 por tanque. Foi utilizado um delineamento experimental inteiramente casualizado, com quatro tratamentos e quatro repetições, sendo os tratamentos (T) constituídos por quatro rações experimentais extrusadas com diferentes níveis de proteína bruta (PB, %): T1 = 18; T2 = 24; T3 = 30 e T4 = 36, isoenergéticas (3.300 kcal kg-1 de ração), isocálcicas e isofosfóricas. Os peixes receberam as rações experimentais pelos seis meses que antecederam o período reprodutivo e, em seguida, foram selecionados a cada dois dias, dois machos e uma fêmea de cada tratamento totalizando-se 12 peixes, pelo período de 22 dias. Os reprodutores foram induzidos hormonalmente, aplicando-se duas doses de extrato bruto de pituitária de carpa totalizando 2,75 e 5,5 mg kg-1 para machos e fêmeas, respectivamente e após um período de 240 horas-grau seus gametas foram coletados e analisados. Nas condições do experimento, os reprodutores de pacu, Piaractus mesopotamicus atingiram à maturação gonadal nas quatro dietas utilizadas, entretanto, os valores dos índices reprodutivos (taxas de fertilização e eclosão) foram inferiores ao recomendado para a produção comercial. Todavia, as características seminais apresentaram diferenças significativas entre as quatro dietas estudadas, recomendandose a ração com 18% PB / Abstract: Was evaluated how protein diets can affect reproductive rates (fertilization and hatching) and seminal characteristics of pacu, Piaractus mesopotamicus reared in cages. Two hundred and twenty-four breeding with four years of age, weight and average length of 2.62 ± 0.59 kg and 47.64 ± 2.83 cm respectively, were distributed in 16 cages (5 m³ / each) in the proportion seven males and seven females, with a density of 2.8 m-3 fish per tank. We used a experimental design completely randomized, composed by four treatments and four replicates, where the treatments (T) wore composed by four extruded experimental diets with different levels of crude protein (CP, %): T1 = 18; T2 = 24; T3 = 30 e T4 = 36, isoenergetic, (3.300 kcal kg-1 of diets), isocalcium and isophosphoric. Fish received the experimental diets for six months before the reproductive period then were selected every two days, two males and one female from each treatment in a total of 12 fish, for a period of 22 days. The breeding wore hormonally induced through two doses of crude extract of pituitary carp totaling 2,75 e 5,5 mg kg-1 for males and females, respectively, and after a period of 240 hoursdegree their gametes were collected and analyzed. Under the conditions of the experiment, the breeding of pacu, Piaractus mesopotamicus reached the gonadal maturation in the four diets, however, the values of reproductive indices (fertilization and hatching) were lower than recommended for commercial production. However, seminal characteristics showed significant differences among the four diets, recommending a diet with 18% CP / Doutor

Effects of artificial water fluctuations called hydropeaking on the detachment rates of adhesive eggs were studied using a rheophlic fish (asp Leuciscus aspius) as a model species. I attempted to relate egg density to abiotic conditions of the spawning ground and identify optimal conditions for the eggs. Egg densities were also studied during spawning season when hydropeaking occurred. In the experimental setup, egg detachment rates were tested with different speeds, substrate type and exposition time and critical conditions for the eggs were assessed.