The aim of the present work, based on two experiments, was to evaluate the impact of photostimulation as a prevention for delaying the sexual maturation of brook trout (Salvenilus fontinalis). Another additional experiment was to describe which effect has photostimulation on the consequences of aggressive behaviour of males. Two experimental groups were established and differed in illumination sources: the metal halide lamps (HAL) and the light emitting diodes (LED). The photostimulation timing (photoperiod) was tested in following experiment. In both tested groups (HAL and LED) the photoperiod was prolonged to 18L:6D in comparison to the control group with natural photoperiod. The results shows that before spawning females and males in both tested groups (HAL and LED) reached significantly higher body weight up to 100 g (=0.05) due to desirable delayed sexual maturation (up to one month). By obtaining the same results in both groups, clearly profitable source of illumination was LED and the time for sufficient application before spawning was 67 days. Moreover photostimulation had also positively reflected in the elimination of aggressive behaviour of males. The results of the present study suggest that photostimulation may be applicable in the intensive culture systems of salmonids in the Czech Republic.

The intestine and associated bacterial microbiota have a central role the physiology and homoeostasis of the host. The understanding of how farming conditions affect the intestine and associated microbiota of fish is the high importance to counteract the potential threats to health and welfare. Thus, this thesis aims to understand the role of stressful husbandry conditions on the intestine and associated microbiota of rainbow trout and Atlantic salmon. Within this context, the role of Pediococcus acidilactici as health promoter was also investigated Chapter 3 investigated the replacement of fishmeal by different plant protein ingredients in rainbow trout. The results of this chapter revealed that the effect of P. acidilactici on the microbiota of distal intestine in rainbow trout was dependent on the ingredients of the diet. The results also showed that the FM substitution induced major changes in the intestinal microbiota. Moreover, the modulation induced by plant-based diets on the microbiota varied according to the ingredients used. Chapter 4 studied the effect of dietary oxytetracycline in the distal intestinal microbiota of rainbow trout and the role of P. acidilactici to ameliorate the impact of antibiotic therapy. Experimental groups fed the diets with oxytetracycline had substantial changes in the distal intestinal microbiota including a decrease in the bacterial diversity. P. acidilactici did not ameliorate the effect of antibiotic therapy in the intestinal microbiota. Chapter 5 used Atlantic salmon during smoltification to study the changes in the microbiota of distal intestine and the role of P. acidilactici to promote intestinal health. The results showed that bacterial communities in the mucosa differed from the digesta. Seawater transfer and P. acidilactici had significant changes in the intestinal microbiota of both mucosa and digesta. However, the modulatory effect of both factors evaluated was larger in the mucosa-associated microbiota than in the digesta-associated microbiota. Furthermore, P. acidilactici induced a significant increase in antiviral-related genes. Chapter 6 investigated the replacement of fish oil by rapeseed oil alone or combined with P. acidilactici on the intestinal health and microbiota of two intestinal regions in Atlantic salmon. Replacement of fish oil by rapeseed oil alone or in combination with P. acidilactici supplementation did not induce major changes in the intestinal health and microbiota. The bacterial communities found were significantly different between the pyloric caeca and mid-intestine. In conclusion, this thesis contributes to new knowledge regarding the effect of dietary supplementation of P. acidilactici and the impact of different potential challenging factors in the health and intestinal microbiota of farmed salmonid species.

The work deals with the rearing of brown trout (Salmo trutta m farion) under controlled conditions. For this study was use intensive hatching metods. We observed and recorded stocking density and her influences an growth, survival in controlled conditions in fish hatchery in Kaplice Ltd

Made available in DSpace on 2016-12-08T16:24:17Z (GMT). No. of bitstreams: 1 PGCA14MA136.pdf: 1647918 bytes, checksum: ff7f5d61d4f253fad4a57167131394e1 (MD5) Previous issue date: 2014-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / World aquaculture has shown a steady growth with emphasis on fish farming . In the inland waters of altitude regions in Brazil, raising trout is an example of exponential growth of production. The rainbow trout Oncorhynchus mykiss is a exotic fish species, native to western North America and was introduced in Brazil to populate the rivers of naturally poor in native fish fauna highlands. The trout production is characterized as an intensive culture, achieving high productivity in small areas, representing an alternative economic activity. However, considering the high investment for the implementation and maintenance of cultivation, it is necessary to evaluate the economic viability of the activity. Therefore, the objective of this study was to analyze the economic viability of raising trout in small, medium and large-scale production based on the economic results obtained. In order to obtain economic data were taken as a basis three producers located in the cities of Bocaina do Sul, Painel and Urubici, being characterized as small and medium (perform fattening) and major producer (produces full-cycle), respectively. Based on the analysis of the economic viability of small and medium producers was observed that the two scales of production were economically viable, and larger scale production provided higher annual income (AI) and higher Net Present Value (NPV), but in general other indicators were very similar for the two producers. The results for the small to medium producer respectively were: Payback period on capital invested (PRC) 5.3 and 5.6 years; Cost Benefit Ratio (CBR) 1.54 and 1.63, Internal Rate of Return (IRR) of 18 and 19%. For large producer was possible to observe that the full production cycle is economically viable, showing excellent economic indicators. The large-scale production provided an annual income of R $ 1,123,467.00, the Payback period was fast (4.1 years on average), the Cost Benefit Ratio was 2.08 and the Internal Rate of Return was 24%. Based on the results it can be concluded that raising trout in small and medium scale is economically viable and that the small-scale production requires full time from producer. From the creation of different scenarios for the different scales of production was observed that the average scale is feasible to hire a technical manager, without compromising the economic results, which was not possible with the small producer. The full production cycle generates excellent economic results and increases the autonomy of the producer in relation to the supply chain, and do only fattening reduces profitability and increases the risks for the producer. Produce supplies such as ration improves economic outcomes and decreases the dependence on the market, but in return makes feed conversion worse. Working only with an industry was less profitable than full production cycle, and in that case the producer is dependent on the production of other properties to keep his unit operating. Finally, it was demonstrated that all scales of production are economically viable, but improper food handling can make the activity unviable, since the feed was the largest item of costing on all scales analyzed / A aquicultura mundial vem apresentando um crescimento constante com destaque para a piscicultura. Nas águas interioranas de regiões de altitude no Brasil, a truticultura é um exemplo de crescimento exponencial de produção. A truta arco-íris Oncorhynchus mykiss é uma espécie de peixe exótica, originária do oeste da América do Norte e foi introduzida no Brasil para povoar os rios das regiões serranas, naturalmente pobres em ictiofauna nativa. A produção de trutas caracteriza-se como sendo uma cultura intensiva, alcançando alta produtividade em pequenas áreas, representando uma atividade econômica alternativa. Entretanto, como é um alto investimento para a implantação e manutenção do cultivo, é necessário avaliar a viabilidade econômica da atividade. Assim sendo, o objetivo do presente estudo foi analisar a viabilidade econômica da truticultura em pequena, média e grande escala de produção com base nos resultados econômicos obtidos. Para a obtenção dos dados econômicos, foram tomados como base três produtores localizados nos município de Bocaina do Sul, Painel e Urubici, sendo caracterizados como pequeno e médio (realizam a engorda) e grande produtor (produz em ciclo completo), respectivamente. A partir da análise de viabilidade econômica do pequeno e médio produtor foi possível observar que as duas escalas de produção foram viáveis economicamente, e a maior escala de produção proporcionou maior renda anual (RA) e maior valor presente líquido (VPL), mas de maneira geral os outros indicadores foram bem semelhantes para os dois produtores. Os resultados para o pequeno e médio produtor respectivamente foram as seguintes: período de retorno do capital investido (PRC) 5,3 e 5,6 anos; relação benefício custo (RBC) 1,54 e 1,63 e uma taxa interna de retorno (TIR) 18 e 19%. Para o grande produtor foi possível observar que a produção em ciclo completo é viável economicamente, inclusive mostrando excelentes indicadores econômicos. Na grande escala de produção foi observado uma renda anual de R$ 1.123.467,00, um período de retorno de capital rápido (em média 4,1 anos), a relação benefício custo de 2,08 e a taxa interna de retorno de 24%. A partir dos resultados pode-se concluir que a truticultura em pequena e média escala é viável economicamente e que a produção em pequena escala exige dedicação integral do produtor. A partir da criação de diferentes cenários para as diferentes escalas de produção se observou que na média escala é viável a contratação de um responsável técnico, sem comprometer os resultados econômicos, o que não foi possível com o pequeno produtor. A produção em ciclo completo gera excelentes resultados econômicos e aumenta a autonomia do produtor em relação à cadeia produtiva, e fazer somente a engorda diminui a lucratividade e aumenta os riscos para o produtor. Produzir insumos como a ração melhora os resultados econômicos e diminui a dependência do mercado, mas em contrapartida piora a conversão alimentar. Trabalhar apenas com frigorífico foi menos rentável que produção em ciclo completo, e neste caso produtor fica dependente da produção de outras propriedades para manter sua unidade beneficiadora operando. Finalmente, foi demonstrado que todas as escalas de produção são viáveis economicamente, porém um manejo alimentar inadequado pode inviabilizar a atividade, já que a ração foi o maior item de custeio em todas as escalas analisadas

Central parts of the Šumava national park has specific nature conditions which we must respect when fish farming is carry out . In 1998 fish {--} hatchery near Borová Lada was established. The fish hatchery exists more than 10 years and we still have no professional report about exploitation this object. (using assorted technologies of rearing, rearing under controlled conditions). The aim of this graduation thesis is evaluation results of trout culture and make proposition new improved technologic process in fish farming on this site. The thesis also includes experiments with initial feeding of fry of brown trout (Salmo trutta morpha fario) carryed out during the spring 2008. The main observed values were survivance, specific growth rate (SGR) and feed conversion ratio (FCR). After 17 weeks of initial feeding fry of brown trout the observed values were achieved: survival of fish 38,2 % , average length SL = 69,0 mm, average weight 4,9 g. Experiments showed that initial feeding of fry of brown trout (Salmo trutta morpha fario) with using feeding mixtures in the Borová Lada fish {--} hatchery is possible and effective.

Quality of populations of brown trout (Salmo trutta m. fario) influence of occurence of freshwater pearl mussel (Margaritifera margaritifera) in river in the Czech Republic. Freshwater pearl mussel is a critically endangered species of animals. It does not have a very specific requirements only on environment but mainly on a specific host for holding glochidia (larval stage of pearl mussel). Thus fish management and migratory permeability of flow for support of existing populations is very important. Basic and essential precondition to support populations of freshwater pearl mussels is the presence of viable populations of brown trout, which represents the only suitable host glochidia. There are five locations with the biggest occurrence of pearl mussel in the Czech Republic - river basins the Blanice, the Teplá Vltava, the Malše, the Rokytnice and the Jankovský potok. The management of these flows is under local organizations of Czech Fishing Union, the National Park and Protected Landscape Area of the Šumava, the Secondary School of Fisheries in Vodňany and Faculty of Fisheries and Protection of Waters. The present management was found in the questionnaire for representatives of farming organizations. According to the answers in the questionnaire, the change of plans of restocking was recommended in the river basins of the Teplá Vltava and the Jankovský potok. There is the cooperation with the Germany was recommended in the river basin of the Rokytnice. The restoration of fish nursery is suitable in the river basin of the Malše. There is the first-rate population of brown trout in the river basin of Blanice, thus the continue in the present fish management for next support of this population in sequence on the populations of freshwater pearl mussel was recommended

The objective of my work was to consider the effect of the Mlýnský potok revitalization on its fish society. My work is based on the ichtyological researches made before and after the revitalization. The brook is situated at the Šumava mountain between the Lipno reservoir and the border with Austria. The revitalisation had a positive effect on biodiversity, abundance and fish biomass. At the same time are here described individual requirements for successful revitalization water stream and in particular fisches, to the these streams. In my work compare achieved results of postponements fishes of the three tracked brooks Horský, Bukový and Mlýnský

This body of research explores the dietary application of a bioactive, solid-state fermentation (SSF) product in contemporary and lupin-containing diets of Nile tilapia (Oreochromis niltoticus) and rainbow trout (Oncorhynchus mykiss). Consequently, the work provides holistic assessment of the influences of SSF products on animal health and performance; depending upon rearing temperature, nutritional physiologies, feed formulations and extrusion conditions; alongside information on the performance of lupins in aquafeeds. The SSF product (at 0.1 % inclusion) improved growth performance of Nile tilapia fed diets containing lupins. Phosphorous retention appeared higher when the SSF product was included in a yellow lupin (Lupinus luteus) diet whilst Mg retention was significantly higher in fish fed narrow-leaf lupin (Lupinus angustifolius). The experimental ingredients did not appear to show any clear effects upon midgut macrostructure. At an ultrastructural level, the fish fed yellow lupin alone, displayed poorest brush border characteristics but those fed yellow lupin and the SSF product showed signs of amelioration since they did not differ significantly from those fed narrow-leaf lupin. Focus was then turned towards a yellow lupin-based diet in rainbow trout, with two inclusion levels of the SSF product. The SSF product significantly improved growth performance and feed efficiency at 0.5 %, with values closer to a fishmeal-based diet than the lupin control. The SSF product increased the digestibility of protein and energy and bioavailability of numerous elements. However, the digestibility and bioavailability of certain nutrients, e.g. fibre and Zn, were only increased with a 0.5 % inclusion. The SSF product influenced vertebral Ca:P ratio but no effect on vertebral morphology was identified. Fish fed yellow lupin kernel meal displayed high Mn concentrations throughout a number of tissues. The intestinal environment was explored in depth, revealing large differences dependent upon SSF product inclusion rate. Fish fed a 0.1 % inclusion exhibited deteriorated brush border characteristics and high diversity of microbes, including increased proportions of key salmonid pathogens. Those fed a 0.5 % inclusion displayed signs of increased surface area at an ultrastructural level, reduced goblet cell numbers and a low microbial diversity; with domination of one particular family, Enterobacteriaceae. Activities of alkaline phosphatase and leucine aminopeptidase within the anterior intestine also appeared to be influenced by SSF product inclusion. Variations in haemato-immunological parameters were also observed between the treatments. In the final experiment, the SSF product was applied, pre-extrusion, to a contemporary rainbow trout formulation, at 0, 0.5, 1.0 and 1.5 %. No significant improvements to performance were identified following SSF product inclusion. However, crude protein digestibility from SSF-supplemented diets was significantly higher than the control and tendencies towards elevated retention of Ca, P, and Mg were apparent. In vitro analysis of free-phosphate release was conducted upon pre- and post-extruded diets, at varying temperatures. This indicated that neither extrusion conditions (105 °C) nor an ambient temperature of 10 °C were sufficient to cease P-liberating capabilities by the SSF product; suggesting that the two conditions combined limited the product’s efficacy in practice. This research evidenced that SSF products can be an effective means of improving the available nutrient profiles of compound diets for both omnivorous, warmwater and carnivorous, temperate finfish. Lupins are a promising alternative protein source but their nutritional value can be substantially improved by SSF product application. Exploration of the effects of SSF products on the intestinal environment revealed that both negative and positive effects on intestinal health can occur, which is highly dependent upon product inclusion rate. The holistic approaches adopted within this series of studies have seldom been performed on monogastric animals and thus provide valuable, transferable information for advancing knowledge in the application of SSF products, exogenous enzymes and lupins to farm animal feeds, in general.

Abstract In this thesis I studied lotic trout predation and its ecological effects, and investigated invertebrate predator-prey interactions under natural and anthropogenically modified flow conditions. Given the growing concern about the reliability of extrapolations from small-scale studies to larger spatio-temporal scales, results of mechanistic small-scale experiments were scaled up by linking them to large-scale field surveys. An intensive survey assessed changes in diel feeding periodicity, prey selection and daily ration of juvenile brown trout (Salmo trutta L.) over the course of the open water period. This survey provides the first field estimates of juvenile brown trout daily rations and indicates crepuscular feeding peaks. Trout selectively preyed on medium- to large-sized prey, shifting towards epibenthic feeding with increasing availability of suitable prey. In a small-scale field experiment, trout displayed clear size-related predation concentrating on invertebrate predators and cased caddisflies, a pattern that scaled up successfully in large-scale surveys. Further, predation effects on large-sized prey were also repeated in a meta-analysis on lotic salmonid predation. While dense blackfly populations in lake-outlet streams are common, mass outbreaks of blackflies in short-term regulated rivers are poorly studied. In our studies the principal invertebrate predator of vernal benthic communities, the caseless caddisfly Rhyacophila, displayed significant preference for blackflies and was almost unable to capture any other prey, thus resulting in passive selection for larval blackflies. Rhyacophila larvae displayed highest capture success in intermediate current velocities, whereas further increases in current velocities decreased capture success. Short-term regulation releases increased both predator and prey drift but, unlike for Rhyacophila, magnitude of drift was unrelated to substrate for blackflies. Indeed, field observations indicated that blackflies rarely face detrimental effects of short-term regulation due to their fast growing rates and early emergence. Moss was the most preferred habitat of Rhyacophila and provided the best buffer against sudden increases in current velocities. These results suggest that several factors maintain spring-time outbreaks of blackfly populations in short-term regulated rivers: exaptation of the dominant blackfly species to prevailing conditions, degradation of the key habitat of the predator, and recurring annual drift losses and diminished capture success of Rhyacophila during short-term regulation releases.

Stream ecosystems and their riparian zones have previously been regarded as two different ecosystems, linked through numerous reciprocal subsidies. Today, ecologists agree that the stream and the riparian zone should be regarded as one system, the stream-riparian ecosystem, which is characterised largely by the subsidies between land and water. The terrestrial subsidies to the stream affect stream-living biota in several ways, some of which are well-known while others less so. The input of wood to the stream from the riparian zone is believed to play an important role in the population dynamics of stream-living fish. In this doctoral thesis, I explore effects of fine stream wood (FW, &lt;10 cm diameter) on wild stream-living young-of-the-year brown trout (Salmo trutta) by reporting and discussing results from laboratory, semi-natural and field experiments. My results show that the local density of drifting prey is higher in the presence of FW than in its absence, and also that young-of-the-year brown trout decrease their diurnal foraging time and prey capture success when FW is added to their habitat. I show that trout decrease their swimming activity in the presence of FW, aggregate in FW bundles, and have lower growth rates than trout without FW access. Also, the degree of sheltering in FW bundles was higher during day than at night in a study performed at low water temperatures; moreover, the presence of an ectothermic nocturnal predator (burbot, Lota lota) did not affect the degree of sheltering in FW bundles by trout. Taken together, my results indicate that young-of-the-year brown trout with access to FW bundles spend considerable amounts of time sheltering in the FW, and by doing so they miss the opportunity for higher growth and foraging rates outside of the shelter. The most probable explanation for this behaviour is that growth is traded off against survival, i.e., the predation risk is higher outside of the shelter. / Stream ecosystems and their riparian zones have previously been regarded as two different ecosystems, linked through numerous reciprocal subsidies. Today, ecologists agree that the stream and the riparian zone should be regarded as one system, the stream-riparian ecosystem, which is characterised largely by the subsidies between land and water. In this doctoral thesis, I explore one such subsidy – the input of fine stream wood (FW) to streams. Wild stream-living young-of-the-year brown trout (Salmo trutta) was chosen as study species. My results show that the local density of drifting prey is higher in the presence of FW than in its absence, and that young-of-the-year brown trout decrease their diurnal foraging time and prey capture success when FW is added to their habitat. I show that trout decrease their activity in the presence of FW, aggregate in FW bundles, and have lower growth rates than trout without FW access. Taken together, my results indicate that young-of-the-year brown trout spend considerable amounts of time in FW bundles, and by doing so they miss the opportunity for higher growth and foraging rates outside of the shelter. The most probable explanation for this behaviour is that growth is traded off against survival. / <p>Artikel 3 publicerades i avhandlingen som manuskript med samma titel.</p>