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Vliv přírodních extraktů na senzorické vlastnosti a prodloužení skladovatelnosti masa pstruha duhového (Oncorhynchus mykiss)
TUNYS, Ondřej
This bachelor thesis evaluates the effects of natural rosemary extract "Inolens 4" on microbiological quality, sensory attributes, colour change and oxidative effect of rainbow trout (Oncorhynchus mykiss). The evaluation is expressed in comparison with the control sample (no additive). Individual analyses took place in different days (0, 3, 6, 10 and 14 days). The microbiological analysis showed values in the range of 1.93 - 2.25; 5.10 - 5.27; 5.12 - 5.80 and 6.34 - 7.66 log CFU*g-1 on days 0, 6, 8 and 10. The limit for freshwater fish consumption (7 log CFU*g-1) was exceeded on 10th day of storage. On the contrary Inolens 0.5 achieved the best result. Sensory analyses also showed that Inolens 0.5 achieved the best results in all sensory attributes (odour, taste, aftertaste, consistency) of cooked fish. Also TBARS analysis evaluating lipid oxidation proved that the application of Inolens 4 extract had a positive effect causing an inhibition of oxidative processes in the muscle. Therefore all the results of this study have shown that the natural extract "Inolens 4" has antioxidant effects extending the storage of rainbow trout meat in combination with suitable storage (vacuum and cooling at 4 +- 1 °C) for up to 10 days. Moreover it has a mild effect on the improvement of sensory properties.
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Diet of Eurasian otter (Lutra lutra) in relation to the stocking of brown trout (Salmo trutta m. fario) and grayling (Thymallus thymallus)
Lyach, Roman ; Čech, Martin (advisor) ; Poledník, Lukáš (referee)
This study aimed to evaluate otter predation on stocked trout and grayling. The diet composition of piscivorous Eurasian otters (Lutra lutra) was studied on the stream Chotýšanka in central Bohemia using spraint (otter faeces) analysis during one winter period (90 days). Stocking took place mostly in the second half of 2005. Around 5000 hatchery-reared brown trouts (Salmo trutta m. fario) of size about 10 cm, 600 graylings (Thymallus thymallus) of the same size and 480 rainbow trouts (Oncorhynchus mykiss) of size about 30 cm were stocked into the stream. Spraints were collected in December 2005 and January 2006. We found and identified 1531 fish in the spraints. The primary food source of otters was fish (almost 85 % of biomass). The main fish prey was small - sized, below 20 g in weight and 13 cm in length. The bulk of otter's diet consisted of less - valued species, especially the gudgeon (Gobio gobio). Other frequently consumed fish species were the European chub (Squalius cephalus), the common carp (Cyprinus carpio), the European perch (Perca fluviatilis), the brown trout and the rainbow trout. Consumption of stocked brown trout was 1,80 %, while cosumption of stocked rainbow trout was 10,90 % of biomass. Otters in this area consumed about 723 - 1446 brown trouts and 72 - 144 rainbow trouts...
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Influence of insect´s components in fish feed on production, health and quality of fish.
HLÁVKOVÁ, Markéta
The first part of my work is devoted to review of alternative components in feeds for fish with special focus on insect. The second part of my work is based on the feeding experiment. Rainbow trouts (Oncorhynchus mykiss) were bred in the aquaria at the Faculty of Fisheries and Protection of Water JU in Vodňany. Experiment was performed in three replications, in 300 litre aquaria with 8 - 10 fish per aquarium. Fish were divided into 5 groups according to the type of feed used. Control group was fed the commercial granule feed and the other four groups were served insect in certain percentage. It was a cricket (Acheta domesticus) and the maggots of giant mealworm beetle (Zophobas morio).Weight and length of fish was registered three times during 2 months of experiment. The sensory analysis of fish meat was done for evaluation of aroma, taste, after taste and consistence of fish muscle. The results show that diet containing insect did not significantly influence weight and growth. In the contrast, sensory analysis proved the difference in analysed parameters. The feed containing only insect was identified as an inappropriate alternative feed. In conclusion, the insect can be used as the alternative feed for fish in the aquaculture. Nevertheless, it is recommended to combine the insect with commercial feeds.
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Vliv podmínek na nutriční hodnotu lososovitých ryb z intenzivních systémů chovu
Vlasák, Jiří
Presented diploma thesis deals with the issue of nutritional characteristics of the fish meat. Practical part is focused on the composition of rainbow trout meat originated from different rearing conditions. Samples for experimental evaluation were taken on June 14th-- 16th, 2014 from five fish-rearing facilities equipped with different rearing system. Ten rainbow trouts in marketable weight were taken from each facility to particular analysis. The fish were measured for length and weight characteristics from which the indices and indicators for condition and exterior evaluation were subsequently calculated. Also the yield and viscerosomatic index of fish were assessed. Biochemical composition of tissues, spectrum of fatty acids and sensory evaluation were assessed for the evaluation of nutritive value. The origin of fish was tested by genetic analysis. The best condition of rainbow trout was found out in flow-through system with short-time recirculation. The highest yield (almost 90%) was reached in fish with initial rearing in fish storage and consequent rearing in fishpond. Biochemical composition of muscle was significantly different mainly in the content of dry matter and fat. There was proved a mutual dependence between the content of dry matter and content of fat. The best results in sensory evaluation were reached in fish from flow-through system, the worst were reached in fish from recirculation facility. Genetic analysis recognised 4 homozygous haplotype and 1 heterozygous haplotype.
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Vliv vybraných kardiovaskulárních léčiv nalézaných ve vodním prostředí na ryby
STEINBACH, Christoph Antonius
Cardiovascular pharmaceuticals are among the most prescribed drugs. As a result of the high consumption, these pharmaceuticals have been frequently detected in waste and surface waters. Verapamil, diltiazem and atenolol are very important representatives of cardiovascular pharmaceuticals; therefore, the present research focused on their acute and sub-chronic effects, bioconcentration, half-life time and metabolism in fish. Moreover, unified protocol for the quantitative assessment of histopathological alterations on the heart ventricle and coronary blood vessels employing heart index calculation was developed with the aim to better assess histopathological changes in fish heart which is one of the targets of cardiovascular pharmaceuticals and other chemicals. The effects caused by high concentrations of the studied substances, verapamil, diltiazem and atenolol, in fish can be considered similar to the therapeutic effects and side effects that are found in humans. The acute exposure to verapamil at the human therapeutic plasma level reduced the heart rate in common carp embryos and larvae. In addition, the acute and chronic exposure to this substance caused peripheral edema and gastrointestinal haemorrhage in carp. Similarly, the histological changes in heart and the blood vessels of the liver in diltiazem exposed rainbow trout suggested vasodilatation similar to the pharmacological effect of diltiazem in the human body. In rainbow trout sub-chronically exposed to atenolol at a human therapeutic blood plasma concentration, histopathological changes in the cardiovascular system were found. The bioconcentration of verapamil, diltiazem and atenolol in fish can be classified as low. Bioconcentration factor (BCF) of verapamil in whole body homogenates of common carp ranged between 6.6 and 16.6. The BCF of diltiazem was also relatively low (0.5-194) in analysed tissues of trout, following the order kidney liver muscle blood plasma. BCF of atenolol in rainbow trout tissues was the lowest among the tested substances (BCF = 0.002-0.27), following the order of liver > kidney > muscle. In the blood plasma, the concentration of atenolol was below the limit of quantification. Verapamil showed a longer half-life time (10.6 days) in fish compared to the human body, indicating the slow rate of biotransformation and/or elimination of verapamil in fish. Estimated half-life times of diltiazem in liver (1.5 h) and kidney (6.2 h) were in the same order of magnitudes as those determined for the human blood plasma. The half-life time of atenolol in trout was not studied, because of its very low bioconcentration. In diltiazem exposed rainbow trout, 8 groups of metabolites of diltiazem with 17 different isoforms were identified using liquid chromatography/high resolution mass spectrometry method. Diltiazem was found to undergo a biotransformation involving desmethylation, desacethylation and hydroxylation in fish. These results showed that diltiazem was metabolised in fish in a similar way like in the human body by desmethylation and desacethylation. On the other hand, hydroxylation, which was involved to a minor extent, seemed to be species specific. Verapamil had no effect on early life stages of common carp at the environmentally relevant concentration after one month lasting exposure. On the other hand, atenolol and diltiazem in environmentally realistic concentrations caused after 42-day exposure some physiological changes in rainbow trout. Namely, atenolol affected haematological and biochemical parameters of the blood in exposed rainbow trout and diltiazem caused changes in the activity of antioxidant enzymes in trout liver and gills. These data indicated that atenolol and diltiazem, when present in the aquatic environment, could be a source of sub-lethal detrimental effects in fish.
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Zhodnocení vlivu použitého krmiva na produkční ukazatele v systému intenzivního chovu lososovitých ryb
Ošanec, Miroslav
The objective of this diploma thesis was to evaluate the production efficiency of selected production feeding mixtures in the system of intensive salmonid farming. The testing was made in the recirculation system of the Danish type in Pravíkov (BioFish s.r.o.). There were the feeding mixtures EFIC Enviro 920 produced by Biomar and Aller gold produced by Aqua Aller used in trials. Production efficiency of the feeding was tested on rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) in two separate time periods (18. 4. -- 3. 7. 2013; 3. 7. -- 28. 8. 2013) and in one comprehensive period (18. 4 -- 28. 8. 2013). Longitudinal and weight parameters, fitness, exterieur and production parameters (FCR, SGR, etc.) were monitored at the beginning and end of the tests, the biochemical compound of tissues and the fatty acids spectrum in muscle were determined and in the end an economic evaluation was made. In the first test period Aller gold feeding achieved better production results in both SiSav (FCR = 1,3; SGR = 0,86 %.d-1) and in Pd (FCR = 1,26; SGR = 0,72 %.d-1). In the second test period EFICO Enviro 920 feeding achieved better production results in both SiSav (FCR = 1,3; SGR = 0,86 %.d-1) and in Pd. In the overall test EFICO Enviro 920 feeding achieved better production results in SiSav (FCR = 1,73; SGR = 0,75 %.d-1) and Aller gold feeding achieved better results in Pd (FCR = 2,77; SGR = 0,45 %.d-1). During the tests there were large fish losses in the tanks that significantly affected the results. According to the production results Aller gold feeding suited the SiSav better and EFICO Enviro 920 suited the Pd better.
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Zhodnocení rybářského managementu pstruhového revíru Svitava 2
Bromek, Petr
The main aim of the diploma thesis is to evaluate the fish management of a trout reserve Svitava 2 and to suggest a correction on the basis of results from the performed surveys and information from the Moravian Fisherman's associotion evidence. Field surveys were realized on 3rd and 4th September 2013. During these surveys 12 fish species out of 5 families were demonstrated by electrofishing. Caught fis were released back to the river measuring weight and lenght. The ichthyologic research was evaulated using indi-cators for fish populations. On account of acquired knowledge and data, I recommend following correction: advance quantity biennial brown trout on 200 fish per hectare, reduce rainbow trout 40 fish per hectare and advence quantity biennial qrayling on 200 fish per hectare.
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Studium vlivu těžkých kovů na biochemický profil u vodních živočichů
Šanda, Radek
This work deals with study of thiol compounds (metallothionein) and the determination of its quantity in the tissues of rainbow trout (Oncorhynchus mykiss). This tissues of the fish were exposed to several concentrations of arsenic. Concentration of metallothionein was measured elektrochemically by using differential pulse voltametry (DPV) by using Brdička's reaction. Metallothionein, which is among the low molecular weight thiols has very strong detoxication effects. Determining of the concentration of this protein could be used to determine the quality and also the health of fish meat.
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Obchodní činnost zaměřená na prodej sladkovodních ryb
Myšková, Eva
MYŠKOVÁ, E. Business activity focused on freshwater fish sale. Bachelor's thesis. Brno: Mendel's University in Brno, 2014 Bachelor's thesis is focused on business activity of company Pstruhařství ČRS s.r.o. which is growing and selling freshwater fish. First part of the 'Bachelor's thesis will analyze the issue of freshwater fish and will define terms : business, business relationships between entrepreneurs, trade and marketing mix. Practical part will analyze company Pstruhařství ČRS s.r.o. in relation to fish sales and will valorize economic results of the company. In discussion part will be described suggestions for improvement of current situation in the company Pstruhařství ČRS s.r.o.
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Farmaka ve vodním prostředí a jejich vliv na ryby
BURKINA, Viktoriia
In this thesis, the impact of atenolol, verapamil, dexamethasone, clotrimazole, and PBSA on the physiological condition and health of rainbow trout (Oncorhynchus mykiss) were studied in vivo and in vitro. The sub-chronic test of atenolol, including at the environmentally relevant concentration, demonstrated that only the fish exposed to atenolol at a concentration of 1000 ?g?L-1 may be at a higher risk of oxidative stress. The second pharmaceutical compound studied was an L-type calcium channel blocker, verapamil. Despite the relatively high concentration of verapamil included in the experiments, the rates of seven hepatic CYP450-mediated reactions (EROD, MROD, PROD, BFCOD, COH, and PNPH) were unchanged in the exposed rainbow trout. This indicates that the activities of the selected CYP450 enzymes were not affected. Exposure to the highest concentration of PBSA (1000 ?g?L-1) led to significantly inhibited glutathione reductase activity. The activities of the EROD, MROD, and PROD enzymes gradually increased, beginning at the environmentally relevant concentrations. We suggest that long-term exposure to PBSA could cause oxidative stress in fish, as indicated by the decreased activity of GR. Moreover, PBSA could interact with intracellular receptors due to the elevated activities of CYP1A (EROD and MROD) and CYP2B (PROD). Rainbow trout showed multiple responses after exposure to clotrimazole. Changes in the haematological parameters in the exposed rainbow trout suggested that the immune system and haemoglobin synthesis were affected. The antioxidant defence enzymes that responded to the clotrimazole exposure influenced the oxidative stress status of the fish. Sub-chronic exposure to clotrimazole did not lead to oxidative stress in any of the fish tissues studied, as indicated by the unchanged TBARS levels. Hepatic energetic pathways were activated in the tested groups after 42 days of exposure to clotrimazole. High levels of glutathione S-transferase were seen in the liver and gill tissues, possibly associated with the detoxification of clotrimazole. The interaction of clotrimazole with intracellular receptors can be expected due to the changes in the catalytic activities of CYP1A1 and CYP3A. The BCF levels in the muscle tissue suggest a moderate bioaccumulation of CLO. The relatively long elimination period for CLO in the fish kidney (half-life = 29 days) may imply a greater potential for adverse effects in this organ. This finding is significant in view of the structural disturbances that appeared in the kidney and testis. The changes observed in the kidney were most prominent in the tubular epithelial cells. Changes in the gonads were only visible in the male specimens, and the pathological changes in the testis may indicate a disruption of steroidogenesis. The potential of clotrimazole and dexamethasone to inhibit CYP450 enzyme activity in rainbow trout hepatic microsomes was investigated in vitro. Clotrimazole non-competitively inhibited EROD activity in the hepatic microsomes, while BFCOD activity was competitively inhibited. PNPH activity was only slightly reduced in the presence of clotrimazole, indicating that it does not significantly interact with CYP2E1. The presence of dexamethasone in the incubations did not affect any of the CYP450 enzymes investigated. Everything considered, the results of the study confirmed that the presence of clotrimazole in the environment is of concern with respect to its impact on the health status of fish. In this thesis, the data of the actual effects of several PPCPs on fish were discussed. Based on the response of selected molecular endpoints, the cardiovascular and anti-inflammatory drugs studied do not present a significant risk for fish, while the antifungal drug and UV-screening agent that were tested may disrupt several physiological processes in fish.
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