Made available in DSpace on 2014-07-29T15:13:43Z (GMT). No. of bitstreams: 1 Tese Raquel Priscila de Castro Oliveira.pdf: 2385507 bytes, checksum: 70f3aa3088e08bd364a210435717e331 (MD5) Previous issue date: 2010-04-30 / This study was developed in order to analyze productive performance, economic evaluation, bromotological composition of fish fillet, body components percentage and glucose level of two of Nile tilapia strains (chitralada and supreme) in three stocking densities (90, 120 and 150 fish/m3) in the raceway system. This work was carried out at the Fish Culture Sector from Universidade Federal de Goias. A total of 1,440 Nile tilapia fingerlings were produced in 24 polyethylene water tanks, adapted to raceway system. Each experimental unit had individual pipe for water supply and flow was regulated to allow total exchange every 30 minutes, regardless of stocking density. The animals were fed three times a day with commercial extruded ration, ad libitum, seven days a week. The design was completely randomized in a 2 x 3 factorial arrangement and four replications. The results were submitted to variance analysis and, in cases of statistical variance, to the Tukey test (5%). After the all variables analysis, it was concluded that both strains presented positive characteristics for production in Goias State in raceway system. Supreme strain, in higher water density, is the one recommended by this study due to greater profitability, and to positive performance aspects. / Esse trabalho foi desenvolvido com o intuito de avaliar o desempenho produtivo, a avaliação econômica, a composição bromatológica do filé, o percentual de componentes do corpo, e a glicemia de duas linhagens comerciais de tilápia-do-Nilo, a chitralada e a supreme submetidas a três densidades de estocagem 90, 120 e 150 peixes/m3 em sistema de alto fluxo de água. O estudo foi realizado no Setor de Piscicultura da Universidade Federal de Goiás. No total, 1440 alevinos de tilápia-do-Nilo foram estocados em 24 caixas d água de polietileno adaptadas ao sistema raceway. Cada unidade experimental era provida de tubulação individual para abastecimento e a vazão foi regulada para troca total a cada 30 minutos, independente da densidade de estocagem. Biometrias mensais foram realizadas e coletados dados para a avaliação. Os animais foram alimentados com ração comercial extrusada, até a saciedade momentânea, sete dias por semana. O delineamento utilizado foi inteiramente ao acaso em esquema fatorial 2x3 e quatro repetições. As médias dos resultados encontrados foram submetidos a análise de variância e, em caso de diferença estatística, ao teste de comparação de médias Tukey (5%). Após a análise de todas as variáveis concluiu-se que ambas as linhagens apresentaram características favoráveis de produção no Estado de Goiás em sistema raceway. A linhagem supreme, na maior densidade de estocagem, foi a recomendada após esse estudo devido a maior rentabilidade e aspectos positivos no desempenho.

Made available in DSpace on 2017-07-10T18:13:14Z (GMT). No. of bitstreams: 1 Douglas J de Camargo.pdf: 424744 bytes, checksum: 7fe4275a9b6844b6fe01aa66e0a86f0d (MD5) Previous issue date: 2013-06-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Vitamins and minerals are required in small quantities for fish growth, reproduction, health and metabolism. The aim of this study was to evaluate the influence of vitamin and mineral supplementation (VMS) in the diet of Nile tilapia. We used 540 fingerlings of Nile tilapia (0.91 ± 0.07 g), distributed in 18 cages of 1 m³ in a completely randomized design with six treatments (0, 0.25, 0.50, 1.00; 2.00 and 4.00% of VMS) and three replications during 116 days. The average water temperature in this period was 23.13 ± 3.00 ° C. At the end of the study, linear effects were observed (p <0.05) for the total length, standard length, weight gain and feed conversion, with better production for the level of 4.00% inclusion of supplement. Survival rates, carcass yield and hepatosomatic index were not affected (p> 0.05) by different supplementation. The hemoglobin, hematocrit, mean corpuscular hemoglobin and mean corpuscular volume were significantly different (p <0.05) among treatments, with higher values for the 4.00% SMV level. Erythrocytes and mean corpuscular hemoglobin concentration did not differ (p> 0.05) among the levels of VMS. We conclude that the level of 0.5% vitamin and mineral supplementation in diets for Nile tilapia improves performance and hematological parameters of fish. / Vitaminas e minerais são exigidas em pequenas quantidades para crescimento, reprodução, saúde e metabolismo dos peixes. O objetivo deste estudo foi avaliar a influência da suplementação mineral e vitamínica (SMV) sobre a dieta de alevinos de tilápia do Nilo. Foram utilizados 540 alevinos de tilápia do Nilo (0,91 ± 0,07g), distribuídos em 18 tanques-rede de 1 m³ num delineamento inteiramente casualizado, com seis tratamentos (0; 0,25; 0,50; 1,00; 2,00 e 4,00% de SMV) e três repetições, durante 116 dias alimentados. A temperatura média da água neste período foi de 23,13 ± 3,00 ºC. Ao final do estudo, foram observados efeitos lineares (p<0,05) para o comprimento total, comprimento padrão, ganho de peso e conversão alimentar aparente, com melhor desempenho produtivo para o nível 4,00% de inclusão do suplemento. Os índices de sobrevivência, rendimento da carcaça e índice hepatossomático não foram influenciados (p>0,05) pelas diferentes suplementações. Os valores de hemoglobina, hematócrito, hemoglobina corpuscular média e volume corpuscular médio foram significativamente diferentes (p<0,05) entre os tratamentos, com valores maiores para o nível 4,00% de SMV. Os eritrócitos e a concentração de hemoglobina corpuscular média não diferiram (p>0,05) entre os níveis de SMV. Conclui-se que o nível de 0,5% de suplementação mineral e vitamínica em dietas para alevinos de tilápia do Nilo melhora o desempenho produtivo e os parâmetros hematimétricos dos peixes.

Made available in DSpace on 2017-07-10T18:13:19Z (GMT). No. of bitstreams: 1 Luciana M Curty Machado.pdf: 1144944 bytes, checksum: ef7bbfda79792b701f520f5f33838f35 (MD5) Previous issue date: 2012-11-09 / The objectives were to evaluate the genetic parameters for the daily weight gain (GPD) of different families of Nile tilapia strain GIFT evaluated in fish farming at UEM/Codapar in Maringá and Sgarbi in Palotina, verify the occurrence of genotype-environment interaction and to compare the morphometric characteristics and performance of single sex populations of male tilapia strains GIFT® and Saint Peter reared in mixed system in Fish Culture Station of the Sgarbi, Paraná, Brazil. The cultivation was carried out during the period June to November 2011, totaling 160 days. The system used in the Fish Culture Station of the Sgarbi was a semi-intensive being adopted the density of 2.0 fish m-2. There were housed 480 fish of the GIFT strain and 1400 fish of the red hybrid, totaling 1880 animals, with an average weight of 15 g. The total GIFT population studied consisted of 720 fish, distributed in 19 families. There were used the complete pedigree information GIFT strain since its introduction in Brazil. For performance testing, two groups of fish previously identified with 240 and 480 specimens, were housed in fish farms ponds in Maringá and Palotina, respectively. The fish were distributed to have representatives of all families in both environments. After rearing period the fish assessed in Maringá and Palotina had a final weight average of 417 g and 280 g, respectively. The covariance components, genetic parameters and phenotypic were estimated proceeding to Bayesian inference, using the computer system MTGSAM. There were used the credibility interval (IC) at 5% probability to determine the differences of genetic parameters and variance components in the local culture. The additive genetic variance to the GPD showed values of 0.113 and 0.045 and the residual variance was 0.036 and 0.024, respectively for Maringá and Palotina. The phenotypic variance estimated for GPD in Maringá was higher than that Palotina. The heritability (h2) of the GPD in Maringá (h2 = 0.707) and Palotina (h2=0.575) were considered high with wide credibility intervals. The genetic correlations and phenotypic to the GPD in Maringá and Palotina had values of 0.20 and 0.13, respectively. The estimates of Spearman correlation, based on breeding values for the individual GPD (0.48) and GPD family (0.59) were significant. The estimates of the correlations of genetic parameters to GIFT strains indicate the presence of genotype-environment interaction. The daily weight gains of tilapia in local assessed are characterized as distinct, and may be influenced by different sets of genes. There were collected and individually assessed 190 and 102 tilapia males, respectively of the GIFT and Saint Peter® strains. The average final weight and daily weight gain among the three genetic groups of the GIFT strain showed no significant differences. However all groups of GIFT strain showed average values of performance and morphometric characteristics superior to hybrid strain Saint Peter®. There was a significant difference only for the height of the GIFT strain of tilapia group higher than the bottom. The morphometric characteristics and growth performance are superior to the GIFT strain, regardless of genetic group, compared to Saint Peter®, except for the head length/standard length of tilapia evaluated. / Objetivou-se estimar os parâmetros genéticos para característica de ganho em peso diário (GPD) de diferentes famílias de tilápia do Nilo da variedade GIFT nas pisciculturas UEM/Codapar em Maringá e Sgarbi em Palotina, verificar a ocorrência de interação genótipo-ambiente e comparar as características morfométricas e o desempenho em cultivo monossexo macho de tilápia das variedades GIFT e Saint Peter® cultivadas em sistema misto na Estação da Piscicultura Sgarbi, Paraná, Brasil. O cultivo foi conduzido durante o período de junho a novembro de 2011, totalizando 160 dias. Na piscicultura Sgarbi foi utilizado o sistema semi-intensivo, sendo adotada a densidade de 2,0 peixes m-2. Foram alojados 480 peixes da variedade GIFT e 1400 peixes da variedade vermelha híbrida, totalizando 1880 animais, com peso médio individual de 15 g. A população GIFT avaliada consistiu de 720 peixes, distribuída em 19 famílias. Foram utilizadas informações de pedigree completo, desde sua introdução no Brasil. Para o teste de desempenho, dois grupos de peixes previamente identificados, o primeiro com 240 e o segundo com 480 espécimes, foram alojados em viveiros nas pisciculturas UEM/Codapar e Sgarbi, respectivamente em Maringá e Palotina. Distribuíram-se os peixes para que tivessem representantes de todas as famílias nos dois ambientes. Ao final do período de cultivo, as tilápias GIFT avaliadas em Maringá e Palotina apresentaram peso médio final de 417 g e 280 g, respectivamente. Os componentes de covariância e os parâmetros genéticos e fenotípicos foram estimados procedendo-se a inferência bayesiana, por meio do sistema computacional MTGSAM. Utilizou-se o Intervalo de Credibilidade (IC), ao nível de 5% de probabilidade, para determinação das diferenças dos parâmetros genéticos e componentes de variância nos locais de cultivo. A variância genética aditiva para o GPD apresentou valores de 0,113 e 0,045 e a variância residual foi de 0,036 e 0,024, respectivamente para Maringá e Palotina. A variância fenotípica estimada para o GPD em Maringá foi superior à de Palotina. A herdabilidade (h2) do GPD em Maringá (h2 = 0,707) e para Palotina (h2 = 0,575) foram consideradas altas, com amplos intervalos de credibilidade. As correlações genética e fenotípica para GPD em Maringá e Palotina apresentaram valores de 0,20 e 0,13, respectivamente. As estimativas da correlação de Spearman, com base nos valores genéticos, para o GPD individual (0,48) e GPD das famílias (0,59) foram significativas. As estimativas das correlações dos parâmetros avaliados na variedade GIFT indicam presença da interação genótipo-ambiente. Os ganhos em peso diário das tilápias nos locais avaliados caracterizam-se como distintos, portanto podem ser influenciados por diferentes conjuntos de genes. Foram avaliados individualmente 190 e 102 tilápias machos, respectivamente, das variedades GIFT e Saint Peter® e os valores médios de peso final e ganho em peso diário entre os três grupos genéticos da variedade GIFT não apresentaram diferença significativas. Porém, todos os grupos da variedade GIFT apresentaram valores médios do desempenho e das características morfométricas superiores à variedade híbrida Saint Peter®. Houve diferença significativa apenas para a altura das tilápias da variedade GIFT do grupo superior em relação ao inferior. As características morfométricas e desempenho zootécnico são superiores para a variedade GIFT, independente do grupo genético, quando comparada à Saint Peter®, com exceção da relação comprimento da cabeça/comprimento padrão das tilápias avaliadas.

Made available in DSpace on 2017-07-10T18:13:25Z (GMT). No. of bitstreams: 1 Dacley Hertes Neu.pdf: 357233 bytes, checksum: 7de2fd1088f9eeda80860bf4529c436b (MD5) Previous issue date: 2011-02-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The higher cost of production at a fish culture is related to nutrition of animals that pass of 50%, so, two experiments were conducted based on digestibility and inclusion of glycerol for the Nile tilapia (Oreochromis niloticus). The purpose of this study was to evaluate digestibility of three sources of glycerol, crude vegetable oil (GBV), semi-purified mixture glycerol (GSM) and semi-purified plant glycerol (GSV) (experiment 1) and then determine to what level of inclusion that food can be held in diets for tilapia and whether it causes changes in blood chemistry characteristics and centesimal composition of animals (experiment 2). In experiment 1, we used 40 fish with mean weight of 343,12 ± 77,71 g distributed in four tanks with 180 liters conical bottom, in a randomized Latin square design. Four experimental diets were prepared, one reference and three tests, composed with the inclusion of 20% of the test food and 80% of the reference diet. Chromic oxideIII was used as inert indicator (0,1% of diet). We obtained the digestible energy of crude glycerol vegetable oil (GBV), semi-purified mixture glycerol (GSM) and semi-purified plant glycerol (GSV) of 3058,55; 2610,55; 1754,70 kcal.kg-1, respectively. For experiment 2, we used the glycerol that contained higher amount of digestible energy (GBV) and it was made five diets containing increasing levels of glycerol (0,0; 2,5; 5,0; 7,5 and 10%) for 79 days and provided to 300 juveniles of Nile tilapia with mean weight of 29,15 ± 8,40 g and 11,55 ± 0,87 cm in length. After this period has evaluated the performance of animals by final weight (FW), length (FL), survival (S), weight gain (WG), feed conversion (FC), specific growth rate (SGR) factor condition (FC), hepatosomatic index (IHS) and visceral fat (VF). For the evaluation of blood biochemical parameters were evaluated protein (PROT), triglycerides (TRIG), cholesterol (COLE), HDL lipoprotein, glucose (GLUC) and VLDL and LDL lipoproteins. To determine the chemical composition were evaluated moisture, lipids, protein and ash. There was no statistical difference between the different treatments on the growth performance of animals. For the biochemical parameters of HDL lipoprotein was only statistically significant difference (P<0.05), being higher in the groups fed with 0,0 and 7,5%, did not differ from animals that were fed 5,0 and 10,0%. For the centesimal composition of tilapia juvenile differences were observed in the amount lipids (P<0.05), which had the highest values in fish fed with 5,0% glycerol. Can be included 10% of the foodl that does not occur any damage to animal health. / O maior custo de produção em um cultivo de peixes está relacionado a nutrição dos animais que passa dos 50%, por isso, foram realizados dois experimentos baseados na digestibilidade e inclusão do glicerol para tilápias do Nilo (Oreochromis niloticus). O objetivo deste trabalho foi avaliar a digestibilidade aparente de três fontes de gliceróis, bruto óleo vegetal (GBV), glicerol semi-purificado misto (GSM) e glicerol semi-purificado vegetal (GSV) (experimento 1) e, posteriormente determinar até que nível de inclusão esse alimento pode ser utilizado em dietas para tilápias e se o mesmo provoca alterações nas características bioquímicas do sangue e na composição centesimal dos animais (experimento 2). No experimento 1, utilizou-se 40 peixes com peso médio de 343,12 ± 77,71 g, distribuídos em quatro tanques de 180 litros com fundo cônico, num delineamento experimental em quadrado latino. Foram confeccionadas quatro dietas experimentais, sendo uma referência e três testes, compostas com a inclusão de 20% do alimento teste e 80% da dieta referência. Como indicador foi utilizado o óxido de cromioIII (0,1% da dieta). Foram obtidos valores de energia digestível do glicerol bruto óleo vegetal (GBV), glicerol semi-purificado misto (GSM) e glicerol semi-purificado vegetal (GSV), de 3058,55; 2610,55; 1754,70 kcal.kg-1, respectivamente. Para o experimento 2, utilizou-se o glicerol que possuía maior quantidade de energia digestível (GBV) e confeccionou-se cinco rações, contendo níveis crescentes de glicerol (0,0; 2,5; 5,0; 7,5 e 10%), por um período de 79 dias e fornecidas a 300 juvenis de tilápia do Nilo com peso médio de 29,15 ± 8,40 g e 11,55 ± 0,87 cm de comprimento. Após esse período foi avaliado o desempenho dos animais através do peso final (PF), comprimento final (CF), sobrevivência (SO), ganho de peso (GP), conversão alimentar (CA), taxa de crescimento específico (TCE) fator de condição (FC), índice hepatossomático (IHS) e gordura visceral (GV). Para as avaliações dos parâmetros bioquímicos do sangue foram avaliados proteína (PROT), triglicerídeos (TRIG), colesterol (COLE), lipoproteína HDL, glicose (GLIC) e lipoproteínas VLDL e LDL. Para a determinação da composição centesimal foram avaliadas a umidade, lipídeos, proteínas e cinzas. Não houve diferença estatística entre os diferentes tratamentos sobre o desempenho zootécnico dos animais. Para os parâmetros bioquímicos apenas a lipoproteína HDL teve diferença estatística (P<0,05), sendo superior no grupo de peixes alimentados com 0,0 e 7,5%, não diferindo dos animais que foram alimentados com 5,0 e 10,0%. Para a composição centesimal dos juvenis de tilápia foi verificada diferença na quantidade de lipídeos (P<0,05), que tiveram os maiores valores nos peixes alimentados com 5,0% de glicerol. Pode ser incluso 10% do alimento que não ocorre prejuízos zootécnicos nem qualquer dano a saúde dos animais.

Following the construction of the Pongolapoort Dam in 1974, the potential impacts on the lower Phongolo River and floodplain due to alterations in the natural flow regime have caused concerns. Fish communities and population structures are directly influenced by these alterations. The only protected section of the Phongolo River is a 15 km reach and its associated pans that flow through the Ndumo Game Reserve. Historic data shows that the community and population structure of the fish in the Phongolo Floodplain has changed as a result of irregular flood releases. The Ndumo Game Reserve plays an important role in the conservation of many ecologically and economically important species as the pans inside the reserve serve as a refuge area in which these species can breed to replenish the fish numbers in the Phongolo River. The fish diversity inside the Ndumo Game Reserve is also higher when compared to outside. During the high flow period fish move into the floodplain pans as a result of the higher water level. Oreochromis mossambicus, the most common species found in this area, utilize Nyamiti Pan for breeding but the health of this species is under pressure due to severe infestations of Lernaea cyprinacaea and nematode parasites. Lernaea cyprinacaea is a parasitic copepod associated with the introduced exotic fish species Cyprinus carpio which is found in large numbers in various pans inside Ndumo Game Reserve. The presence of this alien species in the refuge area raises concerns as it competes for the same resources as the economically important native fish species. Nyamiti Pan is largely populated by adult cichlid species between the ages of six and ten years old. The importance of flood releases which simulate natural flow regime is emphasised by the negative impacts irregular floods have on fish health, community and population structure. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Following the construction of the Pongolapoort Dam in 1974, the potential impacts on the lower Phongolo River and floodplain due to alterations in the natural flow regime have caused concerns. Fish communities and population structures are directly influenced by these alterations. The only protected section of the Phongolo River is a 15 km reach and its associated pans that flow through the Ndumo Game Reserve. Historic data shows that the community and population structure of the fish in the Phongolo Floodplain has changed as a result of irregular flood releases. The Ndumo Game Reserve plays an important role in the conservation of many ecologically and economically important species as the pans inside the reserve serve as a refuge area in which these species can breed to replenish the fish numbers in the Phongolo River. The fish diversity inside the Ndumo Game Reserve is also higher when compared to outside. During the high flow period fish move into the floodplain pans as a result of the higher water level. Oreochromis mossambicus, the most common species found in this area, utilize Nyamiti Pan for breeding but the health of this species is under pressure due to severe infestations of Lernaea cyprinacaea and nematode parasites. Lernaea cyprinacaea is a parasitic copepod associated with the introduced exotic fish species Cyprinus carpio which is found in large numbers in various pans inside Ndumo Game Reserve. The presence of this alien species in the refuge area raises concerns as it competes for the same resources as the economically important native fish species. Nyamiti Pan is largely populated by adult cichlid species between the ages of six and ten years old. The importance of flood releases which simulate natural flow regime is emphasised by the negative impacts irregular floods have on fish health, community and population structure. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

All-male fry are preferred to prevent uncontrolled reproduction before harvest in intensive Nile tilapia (Oreochromis niloticus) aquaculture. Males also grow faster than females. An alternative approach to direct hormonal masculinisation of tilapia fry is to produce fry that are genetically male. However, sex determination system in tilapia is fairly complex. Recent developments have resulted in a linkage map and genetic markers that can be used to analyse the sex determination system. To analyse the genetic sex determination mechanism and to develop marker-assisted selection in the Stirling Nile tilapia population, a fully inbred line of clonal females (XX) was verified using test crosses and DNA markers (mostly microsatellites) to use as a standard reference line in sex determination studies. A series of crosses were performed involving this line of females and a range of males. Three groups of crosses were selected (each group consisted of three families) from progeny sex ratio distributions, and designated as type ‘A’ (normal XY males x clonal XX females), type ‘B’ (putative YY males x clonal XX females) and type ‘C’ (unknown groups of males x clonal XX females), for sex linkage study. For type ‘A’, inheritance of DNA markers and phenotypic sex was investigated using screened markers from tilapia linkage group 1 (LG1) to confirm the LG1-associated pattern of inheritance of phenotypic sex and the structure of LG1. Screened markers from LG1, LG3 and LG23 were used to investigate the association of markers with sex in families of type ‘B’ and ‘C’. In addition, a genome-wide scan of markers from the other 21 LGs was performed to investigate any association between markers and sex, in only families of cross type ‘B’. LG1 associated pattern of inheritance of phenotypic sex was confirmed by genotype and QTL analyses in families of cross type ‘A’. Analyses of genotypes in families of type ‘B’ and ‘C’ showed strong association with LG1 markers but no association with LG3 and LG23 markers. Genome wide scan of markers from all other LGs did not show any significant association between any markers and the sex. The allelic inheritance of two tightly linked LG1 markers (UNH995 and UNH104) in families of type ‘B’ and ‘C’ identified polymorphism in the sex determining locus: one of the alleles was associated mostly with male offspring whereas another allele was associated with both progeny (mostly males in type ‘B’ families, and approximately equal numbers in type ‘C’ families). This knowledge was used to identify and separate supermales (‘YY’ males) that should sire higher proportions of male progeny, reared to become sexually mature for use as broodstock. Two of them were crossed with XX females (one clonal and one outbred) to observe the phenotypic expression of the strongest male-associated allele in progeny sex. The observations of 98% male (99 males out of 101 progeny) and 100% male (N=75) from these two crosses respectively, suggest that a marker-assisted selection (MAS) programme for genetically male Nile tilapia production could be practical. This study also suggests that the departures from the sex ratios predicted using a “simple” XX/XY model (i.e., YY x XX should give all-male progeny) were strongly associated with the XX/XY system, due to multiple alleles, rather than being associated with loci in other LGs (e.g., LG3, LG23). This study also tentatively names the allele(s) giving intermediate sex ratios as “ambivalent” and emphasizes that the presence and actions of such allele(s) at the same sex-determining locus could explain departures from predicted sex ratios observed in some earlier studies in Nile tilapia.

Acoustically, teleost swimbladders have been considered resonant underwater bubbles. Contrary results indicating that bladders are tuned less sharply than such a bubble have been explained by damping of surrounding fish tissue. Recent findings in toadfish and weakfish, however, suggest that the bladder is a highly damped structure and that the frequency of the fish sounds is deternlined as a forced response to sonic muscle movement rather than by resonance of the bladder. In this study I examined acoustics and material properties of swimbladders in Tilapia (an auditory generalist) and the channel catfish (an auditory specialist). The swimbladder was struck with a piezoelectric impact hammer. Amplitude and timing characteristics of bladder sound and displacement were compared for strikes of different amplitudes. Most of the first cycle of sound occurs during swimbladder compression, indicating that the bladder rapidly contracts and expands as force increases during the strike. Harder hits are shorter in duration generate a similar displacement duration with an increasing number of shorter cycles and a 12-15 dB increase in sound amplitude. The frequency spectrum is broad, and the dominant frequency is driven by the strike and not the natural frequency of the bladder. The displacement waveform varies between species catfish exhibit a greater structural stiffness and lower amplitude movement and higher sound amplitude for an equivalent hammer strike. Material properties (peak load, stress, strain, Young's modulus), fiber direction (catfish only), and structural stiffiless of bladders exhibit various patterns suggesting that the bladder walls are not uniform structures. Additionally thickness varies regionally. Notably Young's modulus in both species is similar despite large difference in stress and strain. The modulus of catfish bladder increased 1600-fold when dried. Finally the bladder of both species had a high water content averaging about 70%. These data suggest that viscous damping caused by water in the bladder wall is a major factor responsible for acoustic properties of the teleost swimbladder.

Experiments were conducted to evaluate the ability of prebiotic and probiotic supplementation of commercial fish feed to improve the physiological, immunological, and growth responses of stressed Nile tilapia. To investigate these objectives, tilapia were divided in two major groups: control fish (fed regular commercial feed) and stressed fish (induced by dietary cortisol supplemented to regular commercial feed). Stressed fish were further divided into three sub-groups: stressed fish fed regular feed, stressed fish fed probiotic-supplemented feed, and stressed fish fed a mixture of prebiotic and probiotic supplemented feed. Fish were maintained and tested over an eight-week long experimental period. A variety of physiological, immunological, and growth parameters were measured over the course of the experimental period. These parameters include: serum cortisol, blood glucose, plasma protein, packed cell volume, hepato-somatic index (HSI), spleen-somatic index (SSI), lysozyme activity, feed conversion ratio (FCR), specific growth rate (SGR), protein efficiency ratio (PER), length gain, weight gain, length gain, and condition factor (K). The results of this study does not support the use of these specific prebiotic and probiotic as functional feed additives in Nile tilapia at the levels tested in this study. Further research is needed to determine which probiotic species are best suited for use in Nile tilapia and which prebiotic, when used in combination, will allow these probiotics to have maximum effect.

Made available in DSpace on 2014-06-11T19:22:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-03-27Bitstream added on 2014-06-13T20:09:27Z : No. of bitstreams: 1 sakabe_r_me_jabo.pdf: 484637 bytes, checksum: 524d3e07db3df0075ffd97b02ea8fc33 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Este estudo teve como objetivo avaliar o efeito da suplementação alimentar com ácidos graxos essenciais sobre o desempenho produtivo, variáveis hematológicas, acúmulo de macrófagos e formação de gigantócitos em lamínulas de vidro implantadas no tecido subcutâneo de tilápias. Foram distribuídos 300 peixes (69,86 ± 5,01 g) em 20 caixas (15 peixes/caixa), com capacidade para 310 L, abastecidas com água corrente, vazão de um litro/minuto e aeração suplementar. Os peixes foram submetidos a cinco dietas contendo 28% PD e 3200 Kcal ED/kg. Foram utilizadas duas fontes de ácidos graxos essenciais: óleo de soja (OS) e óleo de linhaça (OL) nas proporções de 100% OS, 75% OS + 25% OL, 50% OS + 50% OL, 25% OS + 75% OL e 100% OL, com quatro repetições por tratamento. Após 15 dias de aclimatação, os peixes receberam as dietas experimentais durante quatro meses, duas vezes ao dia, correspondente a 3,0% da biomassa. Mensalmente foi realizada biometria dos peixes para avaliar o desempenho produtivo. Após 120 dias, os animais foram submetidos ao implante das lamínulas no tecido subcutâneo para avaliação da resposta inflamatória e das variáveis hematológicas (número de eritrócitos, porcentagem de hematócrito, taxa de hemoglobina e volume globular médio) dois, quatro, seis e oito dias após o implante. Não foi observada diferença significativa (P>0,05) entre os tratamentos para os parâmetros de desempenho produtivo e hematológico. Quanto à cinética dos macrófagos e formação de gigantócitos por corpo estranho foi observado crescente acúmulo em função do tempo de implante entre os tratamentos, precocidade na formação de gigantócitos tipo Langhans para os peixes alimentados com 100% de óleo de linhaça ao sexto dia (P<O,OOO 1) enquanto que no oitavo dia houve a formação acentuada de gigantócitos tipo Langhans (P<O,OOO I) nas lamínulas implantadas nos peixes... / The aim of this research was to evaluate the effect of the alimentary supplementation with essentials fattys acids on the productive performance, variables hematologicals, accumulation of macrophages and formation of giant cells in coverslips of glass implanted in the subcutaneous connective tissue of tilapias. 300 fish were distributed (69,86±5.01 g) in 20 aquariums (15 fishes/aquarium), with capacity for 310 L, supplied with current water, f10w of one liter/minute and supplemental aeration. The fish was submitted the five diets contend 28% PD and 3200 Kcal ED/kg. Two acid sources of essentials fattys acids were used: soybean oil (OS) and linseed oil (OL) in the ratios of 100%, 75% + 25% OL, 50% + 50% OL, 25% + 75% OL and 100% OL, with four repetitions for treatment. After 15 days of acclimatization, the fish was received the experimental diets during four months, two times/day, correspondent 3.0% of the biomass. Monthly biometry of the fish was carried through to evaluate the productive performance. After 120 days, the animals were submitted to the imp1antation of coverslips in the subcutaneous connective tissue for eva1uation of the inf1ammatory response and hematologicals variables (number of erythrocytes, percentage of haematocrit, tax of hemoglobin and average corpuscular volume) two, four, six and eight days after the implantation. Significant difference was not observed (P>O,O5) between the treatments for the parameters of productive and hematological performance. All that to kinetic of the macrophages and the formation of giants cells for strange body increasing accumulation in function of the time of implantation between the treatments was observed, premature in the formation of giants cells Langhans type for fish fed with 100% of linseed oil to sixth day (P<O,OOO 1), while that in the eighth day it had the accented formation of giant cell Langhans type (P<O,OOO 1) in coverslips ...(Complete abstract, click electronic access below)