Piscine francisellosis in an infectious emerging bacterial disease that affects several marine and fresh water fish species worldwide, including farmed salmon, wild and farmed cod, farmed tilapia and several ornamental species, for which no commercial treatment or vaccine exists. During 2011 and the first semester of 2012, chronic episodes of moderate to high levels of mortality with nonspecific clinical signs, and widespread multifocal white nodules as the most consistent gross pathological lesion were experienced by farmed tilapia fingerlings at two different locations in Northern Europe. In this study such outbreaks of granulomatous disease were diagnosed as francisellosis with a genus-specific PCR, and 10 new isolates of the bacterium including the one named STIR-GUS-F2f7, were recovered on a new selective “cysteine blood-tilapia” agar and cysteine heart agar with bovine haemoglobin. Ultrastructural observations of the pathogen in Nile tilapia (O. niloticus) tissues suggested the secretion of outer membrane vesicles (OMVs) by the bacterial cells during infection in these fish. This represented the first documented report of isolation of pathogenic Francisella strains from tilapia in Europe. The phenotypic characterisation indicated that isolates recovered were able to metabolise dextrin, N-acetyl-D glucosamine, D-fructose, α-D-glucose, D-mannose, methyl pyruvate, acetic acid, α-keto butyric acid, L-alaninamide, L-alanine, L-alanylglycine, L-asparagine, L-glutamic acid, L-proline, L-serine, L-threonine, inosine, uridine, glycerol, D L-α-glycerol phosphate, glucose-1-phosphate and glucose-6-phosphate. The predominant structural fatty acids of the isolates were 24:1 (20.3%), 18:1n-9 (16.9%), 24:0 (13.1%) 14:0 (10.9%), 22:0 (7.8%), 16:0 (7.6%) and 18:0 (5.5%). Anti-microbial resistance analyses indicated that STIR-GUS-F2f7 was susceptible to neomycin, novobiocin, amikacin, ciprofloxacin, imipenem, gatifloxacin, meropenem, tobramycin, nitrofurantoin, and levofloxacin using the quantitative broth micro-dilution method, while the qualitative disc diffusion method indicated susceptibility to enrofloxacin, kanamycin, gentamicin, tetracycline, oxytetracycline, florfenicol, oxolinic acid and streptomycin. The use of the following housekeeping genes: mdh, dnaA, mutS, 16SrRNA-ITS-23SrRNA, prfB putA rpoA, rpoB and tpiA indicated 100% similarity with other isolates belonging to the subspecies F. noatunensis orientalis (Fno). Koch’s postulates were successfully fulfilled by establishing an intraperitoneal injection (IP) challenge model with STIR-GUS-F2f7 in Nile tilapia. Moreover, the challenge model was used to investigate the susceptibility of 3 genetic groups of tilapia to STIR-GUS-F2f7. The lowest amount of bacteria required to cause mortality was 12 CFU/ml and this was seen as early as only 24 hours post infection in the red Nile tilapia and in the wild type after 26 days, no mortalities were seen in the species O. mossambicus with this dose. The mortality in red O. niloticus was significantly higher than that of the other two tilapia groups when 12 and 120 CFU/fish were injected. It was also observed that when a dose of 1200 CFU/ml was used, the mortality in O. niloticus wild type was significantly lower than that of the other two tilapia groups and no differences were seen among the 3 groups when the highest dose (1.2 x105 CFU/fish) was used. The median lethal dose (LD50) of O. niloticus wild type was the most stable during the experiment (values around 104 CFU/ml) and the highest of the three groups after day 25 post infection. At the end of the experiment (day 45) the LD50 was 30 CFU/ml in the red Nile tilapia, 2.3x104 CFU/ml for the wild type and 3.3x102 CFU/ml for O. mossambicus. This pattern, where the LD50 of the red tilapia was lower than that of the other two groups, was observed during the whole experiment. The outcomes of these experiments suggested that the red Nile tilapia family appeared to be the most susceptible while the wild type Nile tilapia family the most resistant. The complete genome of STIR-GUS-F2f7 was sequenced using next generation sequencing (NGS) Illumina Hi-Seq platform™, and the annotation of the assembled genome predicted 1970 protein coding sequences and 63 non-coding rRNA sequences distributed in 328 sub-systems. The taxonomy of the species Francisella noatunensis was revised using genomic-derived parameters form STIR-GUS-F2f7 and other strains in combination with a polyphasic approach that included ecologic, chemotaxonomic and phenotypic analyses. The results indicated that STIR-GUS-F2f7 and all the other strains from warm water fish represent a new bacterial species for which the name Francisella orientalis was assigned. Moreover the description of F. noatunensis was emended and the creation of a new subspecies within this taxon i.e. Francisella noatunensis subsp. chilense was proposed. The results of this study led to the development of a highly efficacious vaccine to protect tilapia against francisellosis.

Nile tilapia, Oreochromis niloticus, is one of the most important farmed fish globally. One of the most serious bacterial diseases constraining global tilapia production is Francisellosis caused by Francisella noatunensis subsp. orientalis (Fno). Although outbreaks of Fno are increasing worldwide, there are no licenced commercial vaccines to prevent the disease for use on tilapia farms. Thus, the current treatment of choice is the use of antibiotics combined with increasing water temperature up to 30°C. Studies investigating the diversity of circulating Fno isolates and the immune response of tilapia elicited by vaccination against piscine francisellosis are lacking. In addition, the current conventional and molecular tools used for detection of Fno have many drawbacks, making detection of Fno a challenging process. In this study, five clinical isolates of Fno from diverse geographical locations (UK, Costa Rica, Mexico, Japan and Austria), previously characterised by morphology, genotype, antimicrobial susceptibility and virulence, were used in a proteomic study. The whole proteomic cell profile of the five isolates were homogenous by one-dimension sodium dodecyl polyacrylamide gel electrophoresis (1D-SDS-PAGE), while minor differences in the intensity of 15 proteins between the strains were observed by two-dimension SDS-PAGE (2DE), including some important virulence related proteins. The UK isolate was the most significantly different isolate when compared to the other Fno isolates in the current study. The Fno UK isolate had significantly higher abundance of 10/15 of the significantly expressed proteins including four of the essential pathogenicity and virulence related proteins (IglC, GroEL, DnaK, ClpB) compared to the other used Fno isolates. The antigenic profiles of the five Fno isolates were studied by 1D western blotting using tilapia hyper immune sera which recognised an immunodominant band of a molecular weight of ~ 17-28 kDa in all tested Fno isolates. Liquid chromatography-electrospray ionization-tandem mass spectrometry (LC/ESI/MS/MS) identified 47 proteins in this antigenic band. Some of the identified proteins are associated with Fno pathogenicity. 2D western blot analysis of the vaccine isolate (Fno UK) revealed differential antigen recognition between sera from vaccinated and non-vaccinated fish following experimental challenge (26 antigenic spots recognised by sera from vaccinated fish; 31 antigenic spots recognised by sera from vaccinated and challenged fish and 30 antigenic spots recognised by non-vaccinated and challenged fish). The identity of these proteins was determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and some of them are known Francisella virulence related proteins. Bioinformatics analyses revealed diverse categories of proteins with high biological functions, however the vast majority of these proteins are involved in energy production and metabolic pathways of the bacteria. This detailed analysis will facilitate the development of cross-strain protective subunit Fno vaccines and antigen-targeted Fno diagnostics. The outer membrane proteins (OMPs) of the same five Fno isolates were extracted using the ionic detergent sarkosyl. The OMP fraction of the different isolates were separated via 1D-SDS PAGE and the digested peptides of the UK isolate were analysed by LC/ESI/MS/MS. High degree of similarity was observed in the OMP profile of the five Fno isolates with an abundant protein band at 17-28 kDa, which was found to be antigenic by 1D western blot using convalescent tilapia sera. LC/ESI/MS/MS analysis of the OMPs of the Fno UK isolate identified 239 proteins, including 44 proteins in the antigenic band (17-28 kDa). Comparison between the proteins identified in the immunogenic band of whole cell lysate and OMP fraction of the Fno UK isolate showed 30 common proteins between the two preparations, 17 proteins were identified only in the whole cell extract and 14 were identified only in OMP fraction. Outer membrane proteins (e.g. Omp-A), virulence related proteins such (e.g. IglC) and other stress related proteins (e.g. AhpC/TSA family peroxiredoxin) were more abundant in the OMP fraction than the whole cell lysate. In silico analysis enabled prediction of the function and location of the OMPs identified by Mass-spectrometry. The findings of this study provide preliminary data on bacterial surface proteins that exist in direct contact with the host immune defence during infection and offering an insight into their potential role as novel targets for Fno diagnostics and vaccine development. The efficacy of an injectable whole cell oil-adjuvanted vaccine was evaluated against challenge with heterologous Fno isolates in Nile tilapia, Oreochromis niloticus. Three duplicate groups of 130 healthy Nile tilapia (~15 g) were intraperitoneally (i.p.) injected with the vaccine, adjuvant-alone or PBS followed by an i.p. challenge with three Fno isolates from geographically distinct locations. The vaccine provided significant protection to all immunised tilapia groups with a significantly higher relative percent survival (RPS) of 82.3% against homologous challenge, compared to 69.8% and 65.9% after heterologous challenge. Protection correlated with significantly elevated specific antibody responses and western blot analysis demonstrated cross-isolate antigenicity with sera from fish post-vaccination and post-challenge. Moreover, a significantly lower bacterial burden was detected by quantitative real-time polymerase chain reaction (qPCR) in conjunction with significantly greater expression of IgM, IL-1β, TNF-a and MHCII 72 hours post-vaccination (hpv) in spleen samples from vaccinated tilapia compared to those of adjuvant-alone and control fish. The latter results suggested stimulation of protective immune responses following vaccination. In addition, a whole cell formalin killed autogenous immersion vaccine against Fno was developed using the same isolate used for the injectable vaccine. Duplicate tanks of 35 tilapia fry were immersed in the vaccine or in sterile Modified Muller Hinton broth (MMHB) diluted in tank water (1:10 dilution) for 30 s and at 30 days post-vaccination (dpv), all fish groups were immersion challenged with the homologous Fno isolate and monitored for 21 days. A moderate RPS of 43.7% was provided by the vaccine. Serum IgM levels were below the threshold in 30 % of the vaccinated fry 30 dpv. Also, the IgM levels of the vaccinated fry were not significantly different from control fry 21 days-post challenge. A recombinase polymerase amplification (RPA) assay was developed and validated for rapid detection of Fno. The RPA reaction was performed at a constant temperature of 42°C for 20 min. The RPA assay was performed using a quantitative plasmid standard containing a unique Fno gene sequence. Validation of the assay was performed not only by using DNA from Fno, closely related Francisella species and other common bacterial pathogens in fish farms, but also by screening 78 Nile tilapia and 5 water samples collected from UK and Thailand. All results were compared with those obtained by previously established real-time qPCR. The developed RPA showed high specificity in detection of Fno with no cross-detection of either the closely related Francisella spp. or the other species of bacteria tested. The Fno-RPA performance was highly comparable to the published qPCR with detection limits at 15 and 11 DNA molecules detected, respectively. The Fno-RPA was rapid, giving results in approximately 6 min in contrast to the qPCR that required approximately 90 min to reach the same detection limits. Moreover, the RPA was more tolerant to reaction inhibitors than qPCR when tested with field samples. The fast reaction, simplicity, cost-effectiveness, sensitivity and specificity make the RPA an attractive diagnostic tool that will contribute to control the infection through prompt on-site detection of Fno. The overall results of this study indicated that Fno isolates from different origins share a high degree of homology in their proteomic and antigenic profile. Proteomic characterisation data of Fno isolates has contributed to understanding the diversity of Fno isolates and assisted in identifying suitable candidates for developing an effective Fno vaccine. / Moreover, this study has proven the efficacy of a cross protective Fno injection vaccine in tilapia fingerlings, with further optimisation needed for immersion vaccination of fry, and given insights into the immune response of tilapia to vaccination against francisellosis. In addition, it provided a rapid, sensitive, specific and robust molecular tool for detection of Fno that can assist surveillance and control of piscine francisellosis on tilapia farms.

One of the major problems facing aquaculture in Ghana is the non-availability of quality and affordable fish feeds. The present study investigated the nutritional suitability and cost-effectiveness of some Ghanaian oilseed by-products, soybean meal (Glycine spp), cottonseed meal (Gossypium spp), groundnut cake (Arachis hypogaea L.) and groundnut husk, as alternative protein sources to fishmeal (FM) in the diet of Nile tilapia (Oreochromis niloticus L.). The oilseed meals were used individually, as mixtures, as mixtures enriched with methionine and mixtures detoxified by heat processing (autoclaving) and/or addition of supplements (viz. phytase and ferrous sulphate) intended to reduce levels of the most important antinutritional factors (ANFs). Diets, containing the oilseed meals at inclusion levels from 25% to 75% dietary protein, were formulated to be isonitrogenous (320 g.kg-1), isolipidic (100 g.kg-1) and isoenergetic (18 KJ.g-1) and fed to juvenile Nile tilapia at 4-10% of their body weight for a period of eight weeks. Proximate analysis showed that soybean meal (SBM), cottonseed meal (CSM), groundnut cake (GNC) and groundnut husk (GNH) had 500.3, 441.4, 430.5 and 205.6 g.kg-1 crude protein, 38.2, 89.5, 12.8 and 89.2 g.kg-1 crude fibre and 20.19, 19.61, 23.17 and 22.18 kJ.g-1 gross energy respectively. Generally the oilseed meals had good essential amino acid (EAA) profiles with the exception of GNH. The EAA profile of SBM compared very well with FM but methionine and threonine were low (0.73 and 1.50 % of protein respectively) and the same was true for CSM and GNC with even lower levels. Analyzed ANFs in SBM, CSM, GNC and GNH were 17.54, 31.64, 14.86 and 3.99 g.kg-1 phytic acid, 14.09, 1.24 and 2.34 g.kg-1 trypsin inhibitors and 5.80, 6.50, 8.01 and 10.08 g.kg-1 saponin respectively and in CSM 5.6 g.kg-1 gossypol. Nutrient digestibility of these oilseed proteins suggested that Nile tilapia may be able to utilize SBM, CSM and GNC efficiently as dietary protein sources due to high apparent protein digestibility of 94.50%, 84.93% and 90.01% respectively. However, GNH may not be suitable because of very low apparent protein digestibility (27.67%). These protein sources when used individually were shown to cause depressed growth and feed efficiency when substituting more than 50% of the FM protein in diets. This may be attributed to high levels of ANFs, high fibre content and poor EAA profile. However, the use of mixtures of these meals was found to be marginally more effective than that of single sources. This may have been as a result of lower levels of ANFs and improvement in essential amino acid profile due to mixing. Supplementing the mixtures with methionine led to improvement in feed utilization but without significantly improving the nutritive value compared with FM. Heat processing was effective in reducing heat labile trypsin inhibitors in SBM, CSM and GNC by almost 80%, but not phytic acid and saponins, which remained virtually unaffected. Use of meals detoxified by heat processing with/without supplements at 50% inclusion improved growth and feed utilization compared to the unprocessed meals and performance was generally not significantly different from FM. Cost effectiveness analysis revealed that diets containing single feedstuffs or mixtures, particularly those containing equal proportions of oilseed meals and higher proportion of CSM replacing between 50% - 75% FM protein, were more profitable than FM diet. Similarly, the use of heat processed meals at 50% replacement of FM protein yielded greater profit than all other diets including the FM diet. However, essential amino acid supplementation of the meals was less profitable compared to the control. Generally, fish fed diets with oilseed meals would take longer to attain harvest size compared with FM and this could lead to an increase in production costs or a decrease in the number of production cycles which could be achieved within a year. It can be concluded that there is nutritional and economic justification for using SBM, CSM and GNC as partial replacement for FM in diets of Nile tilapia. Based on growth performance, nutrient utilization and economic benefits the diet with heat processed oilseed meal mixtures (containing equal proportions of 16.67% each) at 50% inclusion has the best prospects for replacing FM protein in diets of O. niloticus.

Keimzellen entwickeln sich aus den sogenannten Urkeimzellen, die auch als primordiale Keimzellen (PGC) bezeichnet werden. PGC entwickeln sich während der Embryonalentwicklung und wandern dann in die Gonadenanlagen, wo sie sich vermehren und bei getrenntgeschlechtlichen Arten in Spermien in Männchen und Oozyten bei Weibchen differenzieren. Während der Geschlechtsdifferenzierung sind die Gonaden anfällig für den Einfluss externer Faktoren, wie z. B. der Wassertemperatur. Eine Erhöhung der Wassertemperatur von 28°C auf 36°C während der kritischen Phase der Geschlechtsdifferenzierung, vom 10. bis zum 20. Tag nach der Befruchtung kann zu einer Vermännlichung genetisch-weiblicher Tilapien führen. In der ersten Studie führte eine entsprechende Temperaturbehandlung bei genetisch weiblichen Tilapien zu einem Anteil funktioneller Männchen von 37%. Makromorphologisch konnten die Gonaden 90 Tage alter Weibchen aus Kontroll- und Behandlungsgruppen als unreife Ovarien klassifiziert werden. Erste Reifungsprozesse bis hin zur Oogenese begannen 120 Tage nach der Befruchtung. Die Oogenese konnte mikro-morphologisch weiterhin in folgende Stadien eingeteilt werden: Chromatin Nukleolus, Peri-Nukleolus, kortikale Alveolus, Vitellogenese und reife Eizelle. Oozyten in den Phasen des Chromatin Nukleolus und des Peri-Nukleolus, welche auch die primäre Wachstumsphase darstellen, wurden bei weiblichen Fischen aller Altersgruppen festgestellt. Während weiter fortgeschrittenen Oozytenstadien erst ab einem Alter von 120 Tagen festgestellt werden konnten. Oozyten in der Phase des kortikalen Alveolus wurden demnach frühestens am 120. Lebenstag gefunden. In der Vitellogenese befindliche Oozyten traten erst nach 150 Tagen auf. Reife Eizellen wurden ab einem Alter von 180 dpf festgestellt. Es konnten keine signifikanten Unterschiede in der Eizellentwicklungsstadien zwischen Kontroll- und Behandlungstieren festgestellt werden. Das Ziel der zweiten Studie war die Identifikation von Keimbahn-Stammzellen bei Tilapien, die während der Geschlechtsdifferenzierung verschiedenen Aufzuchttemperaturen ausgesetzt waren. Die Identifizierung der Keimbahn-Stammzellen erfolgte anhand von Immunohistochemie mittels Vasa und PCNA (Proliferierendes Cell Nuclear Antigen) Antikörperfärbung. Es wurden zunächst histologische Schnitte von in Paraffin eingebettetem Ovargewebe hergestellt. Keimbahn-Stammzellen wurden im Keimepithel der Ovarien identifiziert, wobei diese in einzelner, isolierter oder in Clusterform vorlagen. Keimbahn-Stammzellen wurden sowohl bei weiblichen Tieren aus Kontroll- als auch Behandlungsgruppen identifiziert. Zusammenfassend, konnten erstmalig Keimbahn-Stammzellen und ihre Lage in den Gonaden genetisch weiblicher Tilapien, aus Kontroll- und Behandlungsgruppen, mittels Vasa und PCNA Antikörperfärbung charakterisiert werden.

Orientador: Luiz Edivaldo Pezzato / Coorientador: Pedro de Magalhães Padilha / Banca: João Batista Kochenborge / Banca: Hamilton Hisano / Resumo: A tilapicultura é a atividade aquícola que mais cresce no mundo, aumentando a demanda por larvas e alevinos a cada ano. Isso faz com que o desempenho reprodutivo assuma papel fundamental para o sucesso dessa atividade. O presente estudo foi conduzido com o objetivo de avaliar teores de cálcio e fósforo disponível em rações para fêmeas reprodutoras de tilápia-do-nilo, por meio de suas respostas de desempenho produtivo e mineralização óssea. Foram confeccionadas quatro rações isoproteicas e isoenergéticas (32,5% PD e 3300 kcal ED kg-1 ração), com níveis de 0,21-0,14%; 0,37-0,25%, 0,75-0,50%, 1,50-1,00% de Ca e Pdisp, respectivamente, mantendo relação Ca e P de 1,50:1,00. Foram utilizadas 36 fêmeas e 12 machos reprodutores (peso médio de 150 g), distribuídos em quatro aquários de 1000 litros de capacidade útil, na densidade de 9 fêmeas/3 machos/aquário, alimentados duas vezes ao dia, por 180 dias. Não foram observadas diferenças significativas (P>0,05) nos parâmetros morfométricos dos ovos, teores de cálcio e fósforo dos mesmos, desempenho zootécnico e reprodutivo das matrizes, exceto pela taxa média de eclosão de ovos, beneficiada pela dieta com nível mais elevado de Ca e Pdisp. Os parâmetros de mineralização óssea foram afetados pelos níveis de minerais nas dietas (P<0,05). Nos machos, o volume do crânio, densitometria das vértebras, crânio e total, além dos teores de Ca e P nos ossos foram significativamente maiores nos peixes do tratamento com maior nível de inclusão desses minerais. Nas fêmeas, o volume das vértebras, crânio e total, assim como a densitometria do crânio e os teores de Ca e P nos ossos foram significativamente maiores nos animais que receberam a dieta com maiores níveis desses minerais. Conclui-se que níveis ... / Abstract: Tilápia culture is growing rapidly all over the world, thus the demand for larvae and fingerlings increases every year, causing the reproductive performance takes key role in the success of this activity. The present study was conducted to evaluate calcium and available phosphorus in diets for reproductive female Nile tilápia, through their reproductive performance and bone mineralization. Four isonitrogenous and isoenergetic (32.5% PD and 3300 kcal kg-1) diets were formulated, with levels of 0.21-0.14%, 0.375-0.25%, 0.75-0.50%, 1.50-1.00% of calcium (Ca) and disponible phosphorus (Pdisp), respectively. 36 females and 12 males (average weight 150 g) were distributed in four tanks with 1000 liters of capacity, in a density of 9 females and 3 males per aquarium, were fed twice a day for 180 days. There were no significant differences (P >0.05) in morphometric parameters, calcium and phosphorus of the eggs. Egg hatchability were benefited from the diet with the highest level of Ca and Pdisp. The parameters of bone mineralization were affected by the levels of minerals in the diet (P<0,05). In males, the volume of the skull, densitometry of the spine, skull and total body, besides the content of Ca and P in bone, were significantly higher at higher inclusion levels of these minerals. In females, the volume of the vertebrae, skull and total body, as well as the density of the skull and the Ca and P in bone were significantly higher in animals fed the diet with higher levels of these minerals. We conclude that levels of 1.50-1.00% Ca and Pdisp, respectively, in the diet of Nile tilápia broodstock, provides better bone mineralization and higher rates of egg hatchability / Mestre

Por causa da carência de dados sobre a produtividade de tilápias em tanques-rede em escala comercial, produtores e empresários rurais relutam em investir neste sistema de produção. Este estudo objetivou determinar as funções de produção da tilápia do Nilo em tanques-rede; a biomassa econômica de sistemas de produção comercial de tilápias em tanques-rede de diferentes volumes (300 a 400 peixes/m 3 e 500 a 600 peixes/m 3 ); e analisar a influência das condições ambientais no desempenho dos peixes em tanques-rede. Foram estudados 2 casos na região Sudoeste do Estado de São Paulo: (1) represa do Chapadão, 3,3 ha de espelho d’água e profundidade média de 4,00 m, onde foram instaladas nove gaiolas, totalizando 94,50 m 3 de volume útil de produção; e (2) represa da Colônia Nova, 8,8 ha de espelho d'água e profundidade média de 2,60 m, que alojou 27 gaiolas com volume útil total de 235,70 m 3 , ambas localizadas na Usina Paredão, Oriente, SP. De setembro de 2001 a abril de 2002, foram monitorados diariamente o consumo de ração, a mortalidade de cada gaiola e a temperatura da água das represas nos horários das alimentações; pH, oxigênio dissolvido e transparência pelo disco de Secchi foram monitorados quinzenalmente. Foram realizadas biometrias mensais nas gaiolas das duas represas, compreendendo 3% do lote de peixes de cada gaiola. Os peixes foram alimentados com ração extrusada comercial com 32% de proteína bruta, 3 vezes ao dia (09h00m, 13h00m e 17h00m), 7 dias por semana. A taxa de alimentação foi ajustada com base nas biometrias e mortalidade de cada gaiola. Os dados de desempenho foram analisados por análise de variância e regressão. Para a determinação das funções de produção a partir dos dados de campo, foram utilizadas as funções Logística e de Mitscherlich. Não houve diferença de desempenho em relação à biomassa acumulada e peso médio unitário em função do tempo, na densidade de 300 a 400 peixes/m 3, para ambas as represas (P<0,05), possivelmente porque os dois ambientes apresentaram variações dos parâmetros de qualidade de água muito similares e dentro dos limites aceitáveis para a espécie considerada. A densidade de 500 a 600 peixes/m 3 apresentou maior biomassa acumulada e maior eficiência alimentar que a densidade de 300 a 400 peixes/m 3. Não houve diferença significativa (P<0,05) entre o peso médio unitário dos peixes nas duas densidades, mostrando que o aumento na densidade de estocagem não influenciou o crescimento individual dos peixes. Para a densidade de 500 a 600 peixes/m 3, a biomassa que maximizou a lucratividade da produção (biomassa econômica - BE) foi 145 kg/m 3, ponto em que os peixes devem ser despescados ou remanejados. Para a densidade de 300 a 400 peixes/m 3 , a BE foi de 121 kg/m 3. Para a obtenção de peixes com peso médio unitário de 283g, considerando a BE de 145 kg/m 3 , a densidade de 500 a 600 peixes/m 3 possibilitou otimização do espaço e tempo de produção, melhor eficiência alimentar, maior produção por m 3 de tanque-rede, sendo portanto mais rentável economicamente que a de 300 a 400 peixes/m 3. / Cage farming of tilapia is an excellent alternative to utilize lakes, dams and reservoirs inadequate to conventional aquaculture. Low investment on cage or pond farming of tilapia is credited to the lack of reliable production and economical data for commercial scale farming. This study aimed to determine the production functions of Nile tilapia Oreochromis niloticus in cages; the economic biomass at stocking densities of 300-400 fish/m 3 and 500-600 fish/m 3 commercially produced tilapia in cages of different volumes; and the influence of environmental conditions in fish performance in cages. Two cases in São Paulo State south-west region were studied: (1) reservoir Chapadão (Usina Paredão , Oriente, SP), 3.3 ha of surface area, 4.00 m deep, with 9, 94.50 m 3 cages; and (2) reservoir Colônia Nova (Usina Paredão, Oriente, SP), 8.8 ha of surface area, 2.60 m deep, with 27, 235.70 m 3 cages. Feed intake, survival rate and water temperature were monitored daily during scheduled feedings from September 2001 - April 2002. Dissolved oxygen, pH and transparency of water were monitored each 15 days. Fish growth was evaluated by measuring and weighing 3% of fish of each cage. Caged tilapia fed on commercial, floating pellets (32% crude protein) at 0900, 1300 and 1700 h, 7 days for a week. Feeding rate was adjusted based on sample weight and survival rate. Data were analyzed statistically by ANOVA and regression analysis. The Logistic and Mitscherlich functions were chosen to elaborate the production functions. Carrying capacity of both stocking densities 300-400 fish/m 3 and 500-600 fish/m 3 was 200 kg/m 3. No differences were observed in fish performance regarding accumulated biomass and individual average weight over time between both reservoirs for the stocking density of 300-400 fish/m 3 . The stocking density of 500-600 fish/m 3 presented larger accumulated biomass and better feeding efficiency than the stocking density of 300-400 fish/m 3. No significant differences between individual average weight of fish of both densities were observed (P<0.05), meaning that increasing stocking density didn't influence the individual growth of fish. The biomass that maximized the profit to the stocking density of 500-600 fish/m 3 was 145 kg/m 3. Economic biomass (BE) for stocking density of 300-400 fish/m 3 , was 121 kg/m 3. This density had worse feed conversion than 500-600 fish/m 3. Stocking density of 500-600 fish/m 3 , up to individual average weight of 283 g, present many advantages: optimization of space and production time, better feed efficiency, higher fish production per m 3 of cages, and is more profitable than 300-400 fish/m 3.

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.

Orientador: Igor Paiva Ramos / Resumo: Oreochomis niloticus é uma espécie de peixe não-nativa invasora no Brasil, e atualmente, a mais produzida e consumida no país. Contudo, os efeitos/influências ambientais deste sistema de cultivo ainda não estão satisfatoriamente elucidados. Além disso, os escapes são problemas recorrentes nas estações de criação. Assim, o objetivo deste trabalho foi caracterizar a composição da dieta, fatores metabólicos musculares e aspectos parasitológicos de O. niloticus silvestres e cultivados, além de avaliar a sobreposição de nicho trófico desta espécie com a ictiofauna silvestres que habita o entorno dos tanques-rede em uma piscicultura no reservatório de Ilha Solteira, rio Grande, SP. Realizou-se duas coletas de O. niloticus e de outras 17 espécies silvestres, uma no mês de janeiro e outra em julho de 2017. Os espécimes foram eutanasiados, medidos (cm) e pesados (g). Em campo, realizou-se raspagem da pele de O. niloticus com lâminas histológicas para avaliar a presença de ectoparasitas. Todos os peixes foram necropsiados para retirada dos estômagos, fixados e analisados posteriormente. Apenas dos exemplares de O. niloticus foram retiradas amostras de tecido muscular para análises metabólicas e os demais órgãos para avaliação de endoparasitas. A carcaça foi filetada e o tecido muscular foi analisado em mesa de luz para inspeção macroscópica de parasitas encistados. Para todas as análises estatísticas foram consideradas a variação espaço/temporal [espaço (local) = exemplares oriundos do... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Oreochomis niloticus is a non-native invasive fish in Brazil, and currently the most produced and consumed fish in the country. However, the environmental effects/influences of this production system are poorly elucidated. In addition, accidental releases are recurring problems in fish farms. Thus, the aims of this study were to characterize the composition of the diet, muscle metabolic factors and parasitological aspects of wild (from accidental release) and cultivated O. niloticus, besides evaluating the overlap of trophic niche of this species with the wild icthyofauna that inhabits the environment close to the cage fish farm in the Ilha Solteira reservoir, rio Grande, SP. Two samples of O. niloticus and 17 other wild species were taken, during the rainy period (in December 2016) and the dry period (in July 2017). The specimens were euthanized, measured (cm) and weighed (g). In the field, specimens of O. niloticus were submitted to skin scraping to collect the mucus on slides to evaluate the presence of ectoparasites. All fish were necropsied to remove the organs (stomach, intestine, liver, mesentery, kidney, eyes and heart) to parasitological procedures. The stomachs were fixed and the parasitological and diet analysis were performd concomitante.The muscles tissues of O. niloticus specimens were removed, and samples were used in the metabolic analysis, and a part of the material was filleted and submmited to a macroscopic inspection in the candling table, to looking for e... (Complete abstract click electronic access below) / Mestre

Um terço da captura mundial de pescado não é empregada para o consumo direto na alimentação humana, seguindo para elaboração de rações ou é desperdiçada como resíduo. O ideal seria utilizar a matéria-prima em toda a sua extensão e recuperar os subprodutos, evitando a própria formação do resíduo. Com os objetivos de aumentar a receita e a eficiência de produção da indústria e, conseqüentemente, minimizar os problemas ambientais e de sanidade, provenientes do resíduo de pescado, procedeu-se à elaboração da silagem química do resíduo de beneficiamento da tilápia. A tilápia do Nilo (Oreochromis niloticus) é hoje a espécie mais popular no Brasil. A tilápia é cultivada em 22 estados brasileiros e a sua produção anual está entre 30 e 40 mil t. A tilápia foi uma das primeiras espécies oriundas da aqüicultura a ser beneficiada, sendo atualmente comercializada na forma de filés congelados, tecnologia emergente, porém com rendimento de cerca de 30%. Com isso, há necessidade de se transformar o resíduo gerado com o beneficiamento do filé em subprodutos, diminuindo o impacto ambiental. A silagem foi elaborada após homogeneização em cutter e acidificação da biomassa com 3% de ácido fórmico: propiônico, 1:1, adição do antioxidante BHT e manutenção do pH ao redor de 4,0. Foram realizadas análises para determinação da umidade, proteína, lipídios e cinza. Os aminoácidos foram examinados em auto analisador após hidrólise ácida, à exceção do triptofano determinado por colorimetria. A silagem de tilápias apresentou teores semelhantes ou maiores aos preconizados pelo padrão da FAO para todos os aminoácidos essenciais, com exceção do triptofano. Os valores mais elevados encontrados foram para o ácido glutâmico, leucina e lisina. Os resultados indicam uma possível utilização da silagem, preparada a partir do resíduo de processamento da Tilápia-do-Nilo, como fonte proteíca na formulação de ração para peixes. Entretanto, para o aproveitamento da silagem é necessário que se estabeleçam técnicas para remoção do óleo presente com a finalidade de aumentar a estabilidade do produto e seu valor comercial. A oxidação dos lipídios presentes pode causar a formação de peróxidos que podem complexar as proteínas com conseqüente destruição dos aminoácidos. O presente trabalho buscou, também, estabelecer a melhor via de extração do óleo presente na silagem ácida de tilápia do Nilo (Oreochromis niloticus), bem como caracterizar o óleo obtido. A fração lipídica foi extraída por três métodos de extração, a saber, centrifugação (3500 × G/30 min), Soxhlet (AOAC,1990) e Bligh & Dyer (1969). Os resultados para rendimento e índice de peróxido foram, respectivamente, 65,53% e 0,00 mEq/1000g de O2, 44,27% e 25,00 mEq/1000g de O2, 46,87% e 0,00 mEq/1000g de O2. O óleo de tilápia contém, em mg/100g, 28,60; 16,30 e 3,10 dos ácidos oléico, linoléico e linolênico, respectivamente. A centrifugação demonstrou ser a melhor metodologia de extração, por preservar as características físico-químicas do óleo e propiciar maior rendimento. O conteúdo de lipídios na silagem de tilápias, com base na matéria úmida é de 3,99 g/100g, com a retirada da fração lipídica através da centrifugação, restou na amostra apenas 1,54 g/100g de lipídios, o que é considerado um nível aceitável para inclusão em rações para animais. / One third of the world fishing produce is not directly applied in human consumption. Instead, it is used in the elaboration of feed or wasted as residue. It would be ideal to use the raw material thoroughly and to recover by-products, preventing the generation of residues. With the objectives of increasing the income and the production of the industry, as well as minimizing environmental and health problems from fish residues, chemical silage from Tilapia processing residues was produced. The Nile tilapia (Oreochromis niloticus) is the most popular species in Brazil today. Tilapia is cultivated in 22 Brazilian states and its annual production is between 30 and 40 thousand tons. Tilapia was one of the first aquaculture species to be processed after harvesting, being currently commercialized in the form of frozen fillets, however, with a yield of about 30%. Thus, there is a need for transforming the residues generated by the fillet processing into by-products, minimizing the environmental impact. The silage was elaborated after cutter-homogenization and acidification of the biomass with 3% formic acid: propionic, 1:1, addition of antioxidant BHT and maintenance of pH at about 4.0. Analyses for the determination of the moisture, protein, lipids and ash were carried out. The amino acids were examined in an auto analyzer after acid hydrolysis, except for the triptophane which was determined through colorimetry. The tilapia silage presented contents that were similar to or higher than the FAO standards for all essential amino acids, except for the triptophane. The highest values found were for lysine and leucine. The results indicate a possible use of the silage prepared from the Nile tilapia processing residue as a proteic source in the manufacturing of fish feed. However For the use of the silage, oil-removing techniques are necessary in order to increase the stability of the product as well as its commercial value. Lipid oxidation may cause peroxide formation, which can produce complex proteins with a consequent destruction of amino acids. The present work tried to determine the best form of extracting the oil from the acid silage of Nile tilapia (Oreochromis niloticus) and to caracterize the silage oil. The lipid fraction was extracted by three extraction methods: centrifugation (3500 × G·30 min-1), Soxhlet (AOAC, 1990) and Bligh & Dyer (1969). The results for yield and peroxide value were, respectively, 65.53% and 0.00 mEq·1000g-1 of O2, 44.27% and 25.00 mEq·1000g-1of O2, 46.87% and 0.00 mEq·1000g-1 of O2. The lipid fraction showed 28,60; 16,30 and 3,10mg·1000g-1 of oleic, linoleic and linolenic acids, respectively. Centrifugation proved to be the best extraction methodology due to the preservation of the physical-chemical characteristics of the oil and greater yield. The lipid content of the tilapia silage, on a fresh matter basis, was 3.99g·100g-1. With the removal of the lipid fraction by centrifugation, only 1.54 g·100g-1of lipids could be found in the sample, which is considered an acceptable level for its inclusion in animal feed.

Submitted by (edna.saturno@ufrpe.br) on 2017-02-06T16:53:46Z No. of bitstreams: 1 Albino Luciani Goncalves Leal.pdf: 575820 bytes, checksum: 4cc0fd6d3bf7fe9198563d35eae04f53 (MD5) / Made available in DSpace on 2017-02-06T16:53:46Z (GMT). No. of bitstreams: 1 Albino Luciani Goncalves Leal.pdf: 575820 bytes, checksum: 4cc0fd6d3bf7fe9198563d35eae04f53 (MD5) Previous issue date: 2007-02-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Aquaculture requires high-quality feeds with high protein content. So, the determination of less-expensive sources of protein which provides good growth is advantageous. Shrimp wastes have been identified as an animal protein source with great potential. Shrimp protein hydrolysate (SPH), a derived product obtained from shrimp wastes, was considered an excellent alimentary source and may serve as an useful source of protein and flavorants in food formulations. This work aimed to evaluate the nutritional quality of SPH through growth performance of juvenile Nile tilapia and its protein utilization. SPH was included in isonitrogenous diets at levels of 0, 5, 10 and 20% of fish meal protein replacement (SPH0, SPH5, SPH10 and SPH20) and offered to juvenile Nile tilapia (1.7±0.4 g) stocked in 40-L glass aquaria in a 45-day feeding trial. The inclusion of SPH did not produce statistical differences (P≥0.05) on final weight (27.18, 29.46, 26.02 and 25.19 g), survival (100%), relative weight gain (1,571, 1,624, 1,388 and 1,301%), average daily gain, ADG (0.57, 0.62, 0.54 and 0.52 g day-1), specific growth rate, SGR (7.15, 7.38, 6.85 and 6.73 % day-feed conversion ratio, FCR (1.15, 1.09, 1.13 and 1.17) and protein efficiency ratio, PER (2.26, 2.33, 2.20 and 2.14), respectively. The inclusion of SPH in diets for Nile tilapia statistically affected (P<0.05) the final fish body composition. Protein and ash contents decreased and fat content increased with SPH inclusion levels. This study clearly demonstrates that SPH could be included in diets for Nile tilapia without adverse effects on growth and protein utilization. / A produção aqüícola requer rações de alta qualidade, com alto conteúdo protéico. Assim, a determinação de fontes protéicas de menor custo e que promovam bom crescimento é benéfica. Resíduos de camarão têm sido identificados como uma fonte de proteína animal de grande potencial. Hidrolisado protéico de camarão (HPC) foi considerado como uma excelente fonte alimentar e pode servir como uma adequada fonte de proteína e flavorizante em formulações alimentares. Este trabalho objetivou avaliar a qualidade nutricional do HPC através do desempenho em crescimento de juvenis da tilápia do Nilo e sua utilização protéica. SPH foi incluído em dietas isoprotéicas em níveis de 0, 5, 10 e 20% de substituição da proteína advinda da farinha de peixe (HPC0, HPC5, HPC10 e HPC20) e ofertadas aos peixes (1,7±0,4 g) estocados em aquários de 40 L, por um período experimental de 45 dias. A inclusão do HPC não produziu diferenças estatísticas (P≥0,05) no peso final (27,18, 29,46, 26,02 e 25,19 g), sobrevivência (100%), ganho de peso relativo (1.571, 1.624, 1.388 e 1.301%), ganho de peso diário, GPD (0,57, 0,62, 0,54 e 0,52g dia-1), taxa de crescimento específico, TCE (7,15, 7,38, 6,85 e 6,73 % dia-conversão alimentar, CA (1,15, 1,09, 1,13 e 1,17) e eficiência protéica, EP (2,26, 2,33, 2,20 e 2,14), respectivamente. A inclusão do HPC nas dietas para a tilápia do Nilo afetou estatisticamente (P<0,05) a composição final dos peixes. Os teores de proteína e cinzas diminuíram e o teor de gordura aumentou com os níveis de inclusão do HPC. Este estudo claramente demonstra que o hidrolisado protéico de camarão pode ser incluído em dietas para a tilápia do Nilo sem efeitos adversos em crescimento e utilização protéica.