Aquaculture production is increasing annualy and wild fisheries for fishmeal production remain stagnant. As a consequence, extensive research has been deployed to reduce dietary fishmeal inclusion in feeds of farmed species. Usage of alternative protein sources derived from plants continues to increase with the most popular sources being oilseeds, legumes and cereal grains. The downside of these sources is that most of them could directly be used for human consumption arising legitimate criticism from voices referring to countries where protein shortages lead to malnutrition among the population. Jatropha curcas is a tropical oilseed with upcoming popularity for sustainable fuel sourcing. The plant is thought to thrive in semi-arid and arid areas, not just producing oil, but at the same time reclaiming previously eroded land for the local population. For these reasons, annual cultivation of Jatropha curcas is thought to rise over the next decades. After oil is extracted from the seed, the remaining press cake, is currently used as a fertilizer or energy source. This is mostly due to toxic phorbol esters that until recent- ly limited any nutritional applications. In 2011, a method to detoxify Jatropha press cake was developed and paved the way for nutritional research on the resulting detoxified Jatropha curcas kernel meal (JKM) to be launched. JKM offers very high protein content with a balanced amino acid composition suggesting opportunities for usage as a feedstuff in aquaculture diets. JKM further has higher mineral content than comparable oilseeds. However, potential anti-nutritional factors (ANFs) present in the meal could lead to impairment of nutrient availability or other adverse effects. Previous research has already started to evaluate JKM as a protein source for a variety of aquaculture species. This thesis attempts to further identify the potential of JKM as a protein source and assess the effects of JKM on the development of two model cultured teleost species, common carp (Cyprinus carpio) and Nile tilapia (Oreochromis niloticus), as they represent two of the most farmed species, particularly in the tropics. The work comprises growth trials on both species using fishmeal as a subject of replacement in solely fishmeal protein-based diets and on more practical fishmeal/plant protein-based diets. It engages with the effects of phytate, a prominent component of JKM with potential anti-nutritional attributes and commercially available phytase feed supplements to diminish these attributes, as well as oxalate, another plant-specific component with high concentrations in JKM and with limited attention in aquaculture nutrition research. Carp and tilapia showed varying results with different inclusion levels of JKM. For carp 50% fishmeal replacement was possible without losses in growth in diets where fishmeal was the only bulk protein source (Chapter 3.1), Tilapia showed slightly worse growth at a 30% replacement level (Chapter 3.2). A steep decline in growth could be observed when replacing 100% fishmeal with JKM in carp (Chapter 3.1), while tilapia showed no difference at that level compared to 30% replacement (Chapter 3.2). In practical diets, 100% of fishmeal could be replaced by JKM without any adverse effects on growth of carp (Chapter 3.3), while tilapia showed a slight, but significant linear negative correlation with higher inclusion levels of JKM (Chapter 3.4). Phytase addition in tilapia feeds was identified as having no obvious impact on growth in JKM based diets where enough available phosphorus was provided through mineral supplementation (Chapter 4.1). In JKM based diets where available phosphate was not added, phytase addition showed a tendency to increase growth and significantly increased mineral retention and decreased phosphorus effluent contamination (Chapter 4.2). Phytase application through pre-incubating JKM along with citric acid exerted a positive effect of growth on carp when fishmeal protein was replaced by 50% (Chapter 3.1). Phytase was further shown to completely hydrolyze phytate in vitro; however, incomplete hydrolysis was observed in vivo in tilapia (Chapter 4.3). Dietary soluble oxalate added to fishmeal based diets for carp showed better growth parameters, nutrient and mineral retention at inclusion levels 1.5% and higher (Chapter 5.1). For tilapia, a trial could demonstrate adverse effects of oxalate on potassium, calcium, manganese and zinc digestibilities, in this case without negative effects on growth (Chapter 5.2). For both, carp and tilapia, an impact of oxalate on lipid metabolism was evident, lowering body lipid content and blood cholesterol in inclusion levels from 1.5% or higher. JKM can become a valuable alternative to present dietary protein sources in aquaculture feeds. The nutritional attributes of JKM need further research, especially longer-term testing in a commercial scenario and application in commercially produced feeds. Results of this thesis pose a useful addition to previous research and can be referred to for realizing these next steps.

The bacterial pathogens Streptococcus agalactiae and S. iniae have the capacity to infect a wide range of fish species throughout the world, with Nile tilapia (Oreochromis niloticus) being particularly susceptible. Global tilapia aquaculture production was estimated to be 3.5 million tonnes in 2008, and has a significant contribution in the global farmed fish market. Due to their ability to adapt to a wide range of culture systems the commercialisation of tilapia production has occurred in more than 100 countries. However, countries such as China have suffered from severe and extensive outbreaks of streptococcosis in cultured tilapia continuously for many years. Such large-scale outbreaks in China have resulted in a loss of approximately US$0.4 billion in 2011. Fish are permanently exposed to a plethora of pathogens and natural disease outbreaks are complex host-pathogen interactions that seldom involve single pathogen infections. As a consequence, simultaneous infections, alternatively called concurrent or co-infections, are starting to receive interest from aquatic disease researchers. Streptococcus agalactiae and S. iniae infections can both occur in the same geographic area and both S. agalactiae and S. iniae have been found to be present on the same farm in a single disease outbreak. It has been found that a disease outbreak caused by one these pathogens can be followed by another outbreak from the other. These two pathogens have serious effects on the tilapia aquaculture industry yet there is no information regarding S. agalactiae and S. iniae co-infections. Such information would be valuable for understanding epidemiology and the development of improved treatment and control of aquatic streptococcosis infections. The overall aim of this study was to investigate the pathogenesis of S. agalactiae and S. iniae in Nile tilapia. One important aspect of investigating simultaneous infections was to examine if there was any competition or synergy between S. agalactiae and S. iniae in vitro or in vivo. It was found that competition between S. agalactiae and S. iniae in vitro was inconsistent between different experimental systems. Results indicated that there was either no interaction between bacterial species or they coexisted during in vitro competition assays. Whereas, an in vivo model utilising wax moth larvae (Galleria mellonella) suggested that during a simultaneous infection with S. agalactiae and S. iniae the total levels of larval mortality were lower than expected indicating that the pathogens may have interacted with one another in a competitive manner. Investigations were also conducted to identify the expression of virulence factors in vitro for S. agalactiae and S. iniae. Comparisons were then made to ascertain any inter- and intra-species variation. Results demonstrated that both S. agalactiae and S. iniae strains possessed a capsule but varied in their haemolytic activity, blood survival and resistance to complement-mediated killing. These variations suggested that the two bacterial species differed in their mechanisms of pathogenicity where aquatic S. agalactiae strains may initially have a more systemic spread of infection and aquatic S. iniae strains may utilise a more localised spread of infection within the host. This hypothesis was tested through the development of a robust and reliable challenge model for S. agalactiae and S. iniae in Nile tilapia. Through this work it was apparent that fish infected with S. iniae experienced an acute infection with morbidity/mortality occurring 1 – 3 days after exposure. Whereas, the S. agalactiae challenged fish showed a more chronic infection with morbidity/mortality occurring from 1 – 6 days after exposure. Findings clearly demonstrated a more systemic spread of infection during a S. agalactiae challenge with high bacterial loads in all the organs examined. Streptococcus iniae was observed in fewer organs of infected fish and bacterial numbers were substantially lower. Concurrent infections are complex in natural conditions and in experimental studies. As a result a substantial amount of research will be required to fully understand the nature of co-infection with these two streptococci. This study has provided a solid foundation upon which to base future work.

In externally fertilizing fishes, multiple factors of the spawning environment may affect the sperm viability, and thus the fertilization rate. In this thesis, the sperm activation effect of osmolality of non-electrolytes and electrolytes activation media, pH and ion channel inhibitors on Nile tilapia, Oreochromis niloticus, and the effect of environmentally relevant pollutants (cadmium, malathion and rotenone) on sperm fitness (motility and morphology) were investigated. Seminal fluid samples collected from male fishes (200-250g) were subjected to activation treatments, then analyzed for sperm motility using motility score, and motility variables using Hobson sperm tracker for straight line velocity (VSL), beat cross frequency (BCF) and percentage of motile cells (MOT). For the ion channel inhibitors and pollutants, the effect on sperm motility variables of VSL, VCL (curvilinear velocity) and LIN (linearity) were determined. Multivariate analysis was also carried out to determine the effects of ion channel inhibitors and pollutants on sperm subpopulations. The effects of pollutants on sperm morphology were observed using microscopy techniques, namely, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Sperm motility was initiated when the sperm were exposed to hypoosmotic electrolytes and non-electrolytes solution. We also found that sperm show optimal activity at pH range of 6-8 which depicts that the effect of pH on sperm motility is negligible. Lanthanum (calcium channel blocker) and flunarizine (sodium-calcium exchanger pump blocker) were found to inhibit sperm motility at 25 and 5 µM, respectively, suggesting that both ion channels play a significant role in sperm activation in O. niloticus. In contrast amiloride, ouabain and quinine showed no effects on activation, indicating that epithelial sodium channels, sodium-potassium ATPase and voltage gated potassium channels respectively are unlikely to have major roles in sperm activation or motility. The spermatozoa of Oreochromis niloticus were uniflagellate with clearly differentiated oval-shaped head, midpiece and flagellum. Sperm exposed to hypoosmotic shock showed swelling of the midpiece and sleeve structure. The pollutants showed dose- and time-dependent effect on sperm motility of the fast linear sperm subpopulation. Sperm morphology was not affected. Sperm motility was inhibited at 0.44, 0.03 and 0.063 µM, cadmium, malathion and rotenone respectively. Both cadmium and malathion exerted effects very quickly after exposure. The effect of cadmium, which can exert toxicity by calcium antagonism, is consistent with the effects of calcium channel blockes and further supports an important role for calcium in sperm activation and motility. Malathion had effects at relatively low, environmentally relevant concentrations, suggesting the presence of functionally important acetylcholinesterase activity in sperm, and also the presence of activation cytochrome P450 activity. Rotenone, a well known mitochondrial poison, affected motility only after 15 min of pretreatment. The alteration of sperm trajectories in fast linear spermatozoa subpopulation by pollutants at submicromolar concentrations as demonstrated in our study implies potentially serious consequences for fish populations in polluted environments. Furthermore the results indicate that fish sperm motility as assessed by CASA could be an ecologically relevant, sensitive, and ethically acceptable method for toxicity testing in environmental risk assessment.

Seven families of XX and YY homozygous Oreochromis niloticus were produced by mitotic gynogenesis from XY neofemales and their genetic status was verified by multilocus DNA fingerprinting and progeny testing. Two of these gynogenetic families and their corresponding diploid controls were used with 64 AFLP primer combinations in different levels of screening (XX/YY grand pool; XX/YY family pool; XX/YY gynogenetics and XX/XY control individuals) to search for sex-linked or sex-specific markers. Grand pool screening did not reveal any sex-linked markers. Subsequent family pool and individual level screening identified four sex-linked AFLP markers from two primer combinations, three Y-linked (OniY425, OniY382, OniY227) and one X-linked (OniX420). Two of these (OniX420, OniY425) were shown to be allelic. Single locus PCR markers were developed for all of those markers. Linkage analysis of these markers and the sex locus within the source families revealed tight linkage, with estimated map distances of 13cM, 17cM and 20cM for OniY382, OniY227 and OniX420/OniY425 respectively. However, these sex-linked AFLP markers failed to consistently identify sex in unrelated individuals. To develop an effective system for parentage analysis in normal and gynogenetic progeny, AFLPs and multiplexed polymorphic microsatellite loci were investigated. Both were found to be effective, but microsatellites were more appropriate since they are codominant and some loci showed high gene-centromere recombination rates, suitable for discriminating meiotic from mitotic gynogenetics, while AFLPs are dominant markers. Spontaneous diploidization of the maternal chromosome set (SDM) was observed in gynogenetic progeny of one XY neofemale. Maternal inheritance and ploidy status were verified by multilocus DNA fingerprinting and chromosome karyotyping. Close genetic linkage between the red gene and an autosomal sex-reversal gene(s) in gynogenetic progeny and influences of autosomal sex-reversal gene(s) producing males in a fully inbred XX clonal line were previously reported in O. niloticus. To test if the same autosomal sex-reversal locus was responsible in both cases, a series of test crosses was carried out involving XX clonal neomale(s) and homozygous red females. The results indicated the involvement of more than one autosomal sex-reversal locus, one of which is linked to red body colour.

Orientador: Dalton José Carneiro / Banca: João Batista Kochenborger Fernandes / Banca: Marcelo Pereira de Aguiar Toledo / Resumo: O objetivo do presente estudo foi determinado o impacto da inclusão crescente de um blend comercial de ácidos orgânicos (BAO) (0,0%, 1,0%, 2,0% e 3,0%) em três dietas contendo diferentes teores de proteína digestível (PD) (24,30%; 26,81% e 29,32%) sobre o desempenho produtivo, composição corporal, digestibilidade de nutrientes, taxa de eficiência proteica, índices fisiológicos e sobre histomorfometria intestinal de revertidos de tilápia do Nilo. Foram utilizados 468 juvenis de tilápia do Nilo, com peso médio inicial de 16,20 ± 8,03 g, distribuídos em 36 tanques. O delineamento experimental foi inteiramente casualizado com doze tratamentos e três repetições, em esquema fatorial 4x3. Os peixes foram alimentados quatro vezes ao dia até saciedade aparente por 95 dias. Não houve efeito da interação entre os teores de inclusão do BAO e os teores proteicos das dietas sobre as médias de: conversão alimentar (CA), taxa de eficiência proteica (TEP), eficiência de retenção de proteína bruta (ERPB), eficiência de retenção de energia bruta (EREB), extrato etéreo no ganho de peso (EEGP), proteína bruta no ganho de peso (PBGP), largura de vilosidades (LV), túnica muscular (TM) e sobre os índices fisiológicos. Houve efeito da interação entre os fatores estudados sobre as médias de ganho de peso (GP), consumo de ração (CR), taxa de crescimento específico (TCE), fósforo na carcaça (P) e coeficientes de digestibilidade aparente (CDAPB, CDAEB e CDAMM), sendo as maiores médias obtidas com o uso d... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The subject of this trial was to determine the impact of the inclusion of a commercial organic acids blend (BAO) (0.0%, 1.0%, 2.0% and 3.0%) on three diets containing different levels of digestible protein (DP) (24.30%, 26.81% and 29.32%) on the productive performance, body composition, nutrient digestibility, protein efficiency, physiological indices and intestinal histomorphometry of Nile tilapia. A total of 468 Nile tilapia juveniles were used, with initial mean weight of 16.20 ± 8.03 g, distributed in 36 tanks. The experimental design was completely randomized with twelve treatments and three replicates, in a 4x3 factorial scheme. Fish were fed four times daily until apparent satiety for 95 days. There was no effect of the interaction between the OAB inclusion levels and the protein contents of the diets on the means of: feed conversion (FC), protein efficiency rate (PER), crude protein retention efficiency (CPRE), gross energy retention efficiency (GERE), ethereal extract in weight gain (EEWG), crude protein in weight gain (CPWG), villus width (VW), muscle tunica (MT) and physiological indices. There was an effect of the interaction between the factors studied on mean weight gain (WG), feed intake (FI), specific growth rate (SGR), carcass phosphorus (P) and apparent digestibility coefficients (ADCCP, ADCGE and ADCMM). The highest means were obtained with the use of 1% OAB together with the 29.32% DP content. For intestinal histomorphometry, there was interaction between ... (Complete abstract click electronic access below) / Mestre

O excesso de vitaminas lipossolúveis na dieta pode ser acumulado no fígado e causar hipervitaminose em animais. Os objetivos deste trabalho foram determinar a exigência nutricional em vitamina A para juvenis da tilápia do Nilo Oreochromis niloticus, avaliar o desempenho da espécie através do ganho de peso e conversão alimentar e quantificar os depósitos de retinol hepático em animais de uma população revertida sexualmente para o sexo masculino (R; 13,76 ± 1,21 g) e outra não revertida (NR; 9,83 ± 2,30 g). Os peixes foram estocados em aquários de polipropileno de 100 L, em ambiente com condições controladas de temperatura (25,0 ± 1,0 o C) e luminosidade (12h00m:12h00m), e alimentados ad libitum duas vezes ao dia, durante 75 dias, com dietas semipurificadas, suplementadas com 0; 600; 1200; 1800; 2400; 3000; 3600; 4200; 4800 e 5400 UI kg -1 de dieta de retinil palmitato (Rovimix A 500 Roche ® ), em delineamento experimental inteiramente casualizado em esquema fatorial 2x10 (n=4). Ao final do experimento todos os lotes de animais foram sacrificados para a análise de retinol hepático. Sinais severos de deficiência nutricional em vitamina A foram encontrados em animais dos tratamentos 0; 600 e 1200 UI vitamina A kg -1 de dieta; sinais moderados foram também encontrados em animais dos tratamentos entre 1800 e 3600 UI vit A kg -1 de dieta, em ambos os grupos. As interações grupo*nível não foram significativas (P<0,05) para todas as variáveis de desempenho analisadas. Níveis crescentes de inclusão da vitamina A influenciaram o peso final e ganho de peso dos peixes (P<0.05), mas não influenciaram o consumo de ração (P>0,05). Houve um efeito de grupo para todas as variáveis analisadas (P<0,0001). A análise cromatográfica somente detectou depósitos de vitamina A no fígado dos animais alimentados com a dieta contendo 5400 UI kg -1 de retinol. / Excess dietary fat-soluble vitamins can be accumulated in the liver and cause hypervitaminosis in animals. The aim of this research was to establish the vitamin A requirement for Nile tilapia Oreochromis niloticus, evaluating weight gain and food conversion ratio, and quantifying hepatic retinol deposits in a sex reversed, all male population (R; 13.76 ± 1.21 g) and a mixed sex population (NR; 9.83 ± 2.30 g ). Fish were stocked in 100-L plastic aquaria, in controlled environmental conditions of temperature (25,0 ± 1,0 ºC) and luminosity (12h00m : 12h00m), and fed ad libitum, twice a day, seven days a week, during seventy five days with semi-purified diets supplemented with 0; 600; 1,200; 1,800; 2,400; 3,000; 3,600; 4,200; 4,800 and 5,400 IU of retinol palmitate per kg of diet (Rovimix A 500 Roche ® ; 30 % vitamin A) in a totally randomized experimental design, factorial arrangement 2x10 (n=4). At the end of the experiment all groups were sacrificed and liver tissue excised for the hepatic retinol analyses. Severe signs of nutritional deficiency of vitamin A were observed in fish of treatments 0; 600 and 1,200 IU vitamin A kg -1 diet; moderate signs were also found in fish of treatments 1,800 trough 3,600 IU vitamin A kg -1 diet, both populations. Interactions group*level were not significant (P<0.05) to all analyzed performance variables. Increasing levels of dietary vitamin A influenced final weight and weight gain of the fish (P<0.05), but did not influence feed consumption (P>0.05). A group effect was observed regarding all performance variables (P<0.0001). Hepatic retinol quantification (High Performance Liquid Chromatogaphy) detected vitamin A only in fish fed 5,400 IU of retinol per kg of diet.

A Grande São Paulo, composta por 39 municípios, apresenta crescimento urbano e industrial expoente que contribuem para o constante acúmulo de poluentes no ambiente. Ainda assim, exibe áreas verdes remanescentes que contribuem para a sustentabilidade ambiental da cidade, como por exemplo, o Parque Ibirapuera e o Parque Ecológico do Tietê. Nesse contexto, o presente estudo visa verificar a viabilidade em utilizar as O. niloticus como bioindicadoras da poluição por mercúrio no ecossistema aquático dos dois parques da Grande São Paulo. Obteram-se para as tilápias do Nilo do Parque Ibirapuera pertencentes aos pontos de coleta A, B e C durante o inverno as respectivas concentrações de mercúrio total no sangue 2,72±4,20&micro;g/L, 2,45±1,90&micro;g/L e 1,19±0,05&micro;g/L e, no hepatopâncreas as respectivas concentrações de mercúrio de 0,07±0,02 &micro;g/g, 0,06 ±0,005 &micro;g/g e 0,16 ±0,07 &micro;g/g. No verão as tilápias do Parque Ibirapuera apresentaram nos mesmos pontos de coleta as respectivas concentrações de mercúrio total no sangue 2,50±0,84&micro;g/L, 2,67±1,03&micro;g/L e 2,430±0,790&micro;g/L e, no hepatopâncreas as respectivas concentrações de mercúrio de 0,08 ±0,03 &micro;g/L, 0,16 ±0,10 &micro;g/L e 0,09 ±0,03 &micro;g/L. Os peixes do Parque Ecológico do Tietê pertencentes ao ponto de coleta B durante o inverno e verão apresentaram no hepatopâncreas as concentrações de mercúrio total de 0,08±0,01&micro;g/g e 0,10±0,0&micro;g/g e, no sangue as concentrações e mercúrio de 3,59 &micro;g/L e 2,00±1,00 &micro;g/L. A análise estatística de regressão linear foi negativa, alta e com significância estatística apenas entre a idade estimada e a concentração do mercúrio no sangue sugerindo que as tilápias jovens são mais susceptíveis ao acúmulo de mercúrio. Viabilizou-se através deste estudo o uso das tilápias do Nilo como bioindicadores para a poluição por mercúrio nos lagos dos parques da Grande São Paulo. / The Greater São Paulo, formed by 39 cities, presents high urban and industrial growth that contribute to environmental pollution accumulation. In contrast, the same area has residual green areas that contributes to the city\'s environmental sustainability, such as Parque Ibirapuera and Parque Ecológico do Tietê. This study intends to verify the feasebility of using O. niloticus as bioindicators of mercury pollution on the aquatic ecosystem of two Greater São Paulo parks. At winter, on Parque Ibirapuera, the collected Nile Tilapia presented 2,72±4,20&micro;g/L, 2,45±1,90&micro;g/L e 1,19±0,05&micro;g/L mercury concentration on blood and 0,07±0,02 &micro;g/g, 0,06 ±0,005&micro;g/g e 0,16 ±0,07 &micro;g/g mercury concentration on liver for collect points A, B and C respectively. At summer, Nile Tilapias collected on the same three points, presented 2,50±0,84&micro;g/L, 2,67±1,03&micro;g/L e 2,430±0,790&micro;g/L mercury concentration on blood and 0,08 ±0,03 &micro;g/L, 0,16 ±0,10 &micro;g/L e 0,09 ±0,03 &micro;g/L on liver. The Parque Ecológico do Tietê\'s fish, from point B, presented 0,08±0,01&micro;g/g mercury concentration on liver and 3,59 &micro;g/L mercury concentration on blood. At summer, the mercury concentrations were 0,10±0,0&micro;g/g on liver and 2,00±1,00 &micro;g/L on blood. The linear regression statistical analisys was negative, high and with statistical significance only between estimated age and blood mercury concentration, indicating that young tilapia are more likely to accumulate mercury. The use of Nile Tilapia as bioindicators for mercury pollution on Greater São Paulo\'s park lakes was made viable through this study.

Made available in DSpace on 2014-06-11T19:22:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-06Bitstream added on 2014-06-13T18:48:58Z : No. of bitstreams: 1 novaes_af_me_jabo.pdf: 1108978 bytes, checksum: 6edc74fb32aa05ccc7e72ae5d3614ab1 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Nos últimos anos, a demanda pelo pescado tem aumentado significativamente. Atualmente, a pesca, que contribui com a maior parte deste produto, vem apresentando estagnação, ou ligeira queda na oferta em alguns anos como foi o caso de 2006. Em contrapartida, a aquicultura moderna, que passa por grandes avanços científicos e tecnológicos, vem suprindo esta deficiência no mercado. O Brasil, detentor de 12% de toda água doce mundial, deverá se tornar brevemente um grande produtor no cenário mundial. Um dos grandes diferenciais do país, além de possuir clima favorável, é a disponibilidade de grandes reservatórios, que tem sido aproveitado para o cultivo de peixes em tanques-rede. O presente estudo, desenvolvido em piscicultura comercial, no Reservatório de Furnas, curso médio do rio Grande, município de São José da Barra MG teve como objetivo comparar os principais indicadores zootécnicos e econômicos da tilapicultura em sistema super-intensivo (tanques-rede) em duas diferentes dimensões 6 e 18 m3. Foram utilizados 12.960 juvenis machos revertidos da tilápia-do-nilo (Oreochromis niloticus). Durante todo o período experimental, os peixes receberam ração extrusada especial para tilápias em cultivos super-intensivo e a oferta variou de acordo com a biomassa e temperatura da água, iniciando com 8% e decrescendo até 1%. Foram avaliados os seguintes índices zootécnicos: sobrevivência (%), peso médio (g), biomassa (kg), ganho de biomassa (kg), ganho em peso diário (g), conversão alimentar aparente e densidade (kg/m3). A análise econômica foi elaborada a partir da determinação do custo total de produção e do lucro de cada tratamento. Os dados deste estudo permitem concluir que, embora não diferindo nos principais indicadores zootécnicos, a produção de tilápias em tanques-rede de maior dimensão proporcionou menor custo total médio e maior rentabilidade / In the past few years, demand for fish has increased significantly. At present, fishing, which contributes with the largest part of this product, has shown stagnation or slight falling in the offer in some years, as in the case of 2006. On the other hand, modern aquiculture, with technological and scientific improvement, has been supplying this deficit on the market. Brazil, with 12% of the world's fresh water, will probably become one of the greatest consumers soon. Besides the favorable weather, there is also the availability of large reservoirs, which has been used for the growing of fish in net cage. The present study, developed at Furnas reservoir, medium course of Grande river, in São José da Barra/MG, had as its aim compare the economic and zootechnic indicators of tilapiculture in super intensive system net cages in two different dimensions 6 and 18 m3. 12,960 reversed male juvenils from Nile tilapia were used (Oreochromis niloticus). During the experiment the fish received (extrusada) special ration for tilapia in super intensive culture and the offer varied according to the biomass and water temperature, beginning with 8% and decreasing until 1%. The following zootechnic indexes were evaluated: survival (%), average weight (g), biomass (kg), gain of biomass (kg), gain of daily weight (g), apparent nutritional conversion and density (kg/m3). The economic analysis was made after the determination of the total cost of the production and the profit of each treatment. The data in this study allows the conclusion that the production of tilapia in (net cages) of bigger dimension offered bigger rentability

Orientador: Elisabete Maria Macedo Viegas / Banca: Angélica Simone Cravo Pereira / Banca: Eliana Setsuko Kamimura / Banca: Rose Meire Vidotti / Banca: João Batista Kochenborger Fernandes / Resumo: Este trabalho foi desenvolvido para avaliar a eficiência de três métodos de abate da tilápia do Nilo (Oreochromis niloticus) sobre a qualidade de filés congelados. Esta pesquisa foi executada em duas etapas que consistiram na aplicação dos métodos de abate por eletronarcose (ChE), mistura gasosa (CO2N) e hipotermia (AG). Na primeira etapa foi analisado o peixe inteiro resfriado, avaliados índices de rigor mortis, degradação de ATP, pH, BNV, NNP, contração muscular, cor e texuta instrumental e avaliação sensorial. Os peixes abatidos por ChE apresentaram um retardamento no tempo de entrada em rigor mortis, este mesmo tratamento apresentou R2 de 0,92 na interação entre a degradação de ATP e rigor mortis. O pH foi afetado pelos tratamentos e pelo tempo. Os maiores valores de BNV ocorreram no abate por ChE. O abate por AG apresentou 452 mg NNP/100g. O tempo de estocagem causou uma leve diminuição na textura instrumental no abate por ChE. A L* aumentou com o tempo para os abates por ChE e CO2N. A análise sensorial mostrou um R2 de 0,94; 0,98 e 0,96 para os abates por ChE, CO2N e AG, respectivamente. Na segunda etapa foram aplicados os mesmo métodos de abate da primeira, seguido da filetagem e análises dos filés congelados. Avaliados índices físicos e químicos de qualidade como BNV, TBARS, DSC, CRA, perda de água por cozimento e descongelamento, textura e cor instrumental. Não houve diferença para os valores de BNV. A maior variação de pH ocorreu no abate por AG. Os valores de TBARS foram crescentes ao longo do tempo. O método de abate influenciou a temperatura de desnaturação da actina. A cor L* para o abate por ChE se mantiveram superiores. Ocorreu uma redução significativa na textura. As perdas de água por cozimento e descongelamento e a CRA apresentaram diferença no abate por AG. A partir desses... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study aimed to evaluate the efficacy of three methods of slaughter of Nile tilapia (Oreochromis niloticus) and the quality of frozen fillets. This research was performed in two steps consisting in applying the methods of killing by electric shock (ChE), gas mixture (CO2N) and hypothermia (AG). The first step was analyzed whole fish cold, evaluated indices of rigor mortis, degradation of ATP, pH, N-BVT NNP, muscle contraction, and texture instrumental color and sensory evaluation. Fish killed by ChE showed a delay in the time of entry into rigor mortis, this same treatment showed R2 0.92 in the interaction between the degradation of ATP and rigor. The pH was affected (p> 0.05) by treatments and time. The highest values occurred in the BNV slaughter by ChE. Slaughter presented by AG 452 mg NNP/100g. The storage time caused a slight decrease in instrumental texture slaughter by ChE. A L* increased with time for slaughter for ChE and CO2N. Sensory analysis showed an R2 0.94, 0.98 and 0.96 for withdrawals by ChE, CO2N and AG, respectively. In the second step we applied the same methods of killing the first, followed by filleting and analysis of frozen fillets. Indices evaluated physical and chemical quality as N-BVT, TBARS, DSC, WRC, cooking and drip loss, texture and instrumental color. There was no difference in the values of N-BVT. The biggest change occurred in pH slaughter by AG. TBARS values were increased over time. The method of killing influence the denaturation temperature of actin. The color L * for slaughter by ChE remained higher. There was a significant reduction in texture. The analysis of cooking and drip loss and WRC differ (p>0.05) at slaughter by mainly AG. From these results it is concluded that is posssible in humanitarian point of view and the quality of the fish, there are feasibility of using electric shock as an... (Complete abstract click electronic access below) / Doutor

Submitted by (edna.saturno@ufrpe.br) on 2017-02-08T12:55:47Z No. of bitstreams: 1 Augusto Jose Nogueira.pdf: 737725 bytes, checksum: 139b676fcd27f96b8b2f945bc0628bac (MD5) / Made available in DSpace on 2017-02-08T12:55:47Z (GMT). No. of bitstreams: 1 Augusto Jose Nogueira.pdf: 737725 bytes, checksum: 139b676fcd27f96b8b2f945bc0628bac (MD5) Previous issue date: 2003-02-07 / This work was accomplished in the Aquiculture Experimental Station belong to the Fisheries Department of the UFRPE and in the Fish culture Station of CHESF, Paulo Afonso-BA, in the period between the year of 2001 and 2002. Aimed to study some aspects of the reproductive biology of the Nile-tilapia, Oreochromis niloticus, chitralada strain, and the patterns of growth of its offspring in different experimental conditions. Initially, it was investigated the growth performance among sexually reverted and no-reverted fish, in two offspring strains with patterns of growth denominated type A and B. These offspring were a result of the breeding crossing between the broods fish, having the following patterning of growth: ♂A X ♀A and ♂A X ♀B. First, the growth was compared among the reverted fish and no-reverted ones, inside of each group and between them; a intra and inter-specific comparisons. Soon after, it was observed the growth of the successive strains from non-reverted fish stocks, a comparative study of the growth between males and females, and finally, the study of the sexual proportionality from the same spawned fish. According to the results, there was not significant difference (P=5%) among reverted fish and no-reverted ones, as for the intra-groups (A with A and Bwith B) as well for the inter-group comparison (A and B). There was no statistical difference among the offspring F1 and F2 of no-reverted fish, and between the males and females, when they were cultivated in tanks. There was a difference in growth when the males cultivated in earthen pond were compared with those females reared tanks. Males were larger, statistically,. With relationship to the sexual proportionality inside spawning, it was noticed that the male was more predominant than the female, in a sexual proportion that varied among 4:1 - 2:1. It could be concluded that non-reverted fish grew as much as the reverted ones, in consequence of two factors: 1) the females grow as much as the males and 2) the number of males is always predominant over females in any spawning. The variables physical-chemistries of the water were considered in the normal conditions for the practice of fish culture. The group of tilapia Chitralada here investigated is a strong candidate for the program of species selection based on AGV (Additive genetic variation), done in several parts of the world. It is recommended the effective control of this tilapia strain and wider scientific observations, in order to verify the continuous effect of theresults obtained in this work. / Este trabalho foi realizado na Estação de Aqüicultura do Departamento de Pesca da UFRPE e na Estação de Piscicultura da CHESF, Paulo Afonso-BA, no período entre o ano 2001 e 2002. Visou estudar alguns aspectos da biologia reprodutiva da tilápia nilótica, Oreochromis niloticus, linhagem chitralada, e os padrões de crescimento de sua prole em condições experimentais diferentes. Inicialmente, observou-se o estudo de crescimento entre peixes revertidos e não-revertidos sexualmente para macho, pertencentes à duas proles denominadas de grupo-padrão de crescimento tipos A e B, oriundas de cruzamentos entre reprodutores com os seguintes padrões de crescimento: ♂ tipo A X ♀ tipo A e ♂ tipo A X ♀ tipo B. Inicialmente, comparou-se o crescimento entre os peixes revertidos e não-revertidos de ambos os grupos; uma comparação intra e interespecífica. Em seguida, realizou-se o estudo de crescimento de proles sucessivas de peixe não-revertidos, estudo comparativo de crescimento entre machos e fêmeas, e, por fim, o estudo da proporcionalidade sexual por grupos isolados de desova. De acordo com os resultados, os peixes não-revertidos cresceram tanto quanto os revertidos, nacomparação intragrupo (A com A e B com B) quanto na intergrupo (A e B). Também não houve diferença estatística no crescimento entre as proles F1 e F2 de peixes não-revertidos. Da mesma maneira, não houve diferença no crescimento entre os machos e fêmeas dessas proles quando cultivadas em tanques de alvenaria. Só houve diferença significativa quando se compararam os machos da prole cultivada no viveiro com aquelas fêmeas cultivadas nos tanques de alvenaria. Quanto à proporcionalidade sexual por desova, notou-se que o macho foi mais predominante do que a fêmea, numa proporção sexual que variou entre 4:1 - 2:1. Pôde-se concluir que: dentro das características de crescimento da tilápia Chitralada estudada, os peixes não-revertidos cresceram tanto quanto os revertidos, em conseqüência de dois fatores: 1) as fêmeas crescem tanto quanto os machos e 2) o número de machos é sempre predominante em cada desova. As variáveis físico-químicas da água estavam dentro do considerados "valores normais" à piscicultura moderna. O grupo de tilápia chitralada aqui investigado é um forte candidato ao programa de seleção de espécie baseado no AGV (Additive genetic variation),conduzido em várias partes do mundo. Recomenda-se o controle efetivo dessa linhagem de tilápia e observações científicas mais amplas, a fim de verificar o efeito contínuo dos resultados aqui obtidos.