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The effect of selected parameters of stream water on gill morphology of brook charr and the structure of ichthyofauna of the Jizera Mountains
Hušek, Jiří ; Švátora, Miroslav (advisor) ; Dušek, Martin (referee)
The occurrence of ichthyofauna on the territory of the Jizera Mountains (Northern Bohemia, Czech Republic) is limited, besides other factors, by the water chemistry. pH value and pH-related concentration of inorganic monomeric aluminum (Ali) are crucial parameters of the water, determining the survival of fish in streams. Low pH and high concentrations of Ali cause severe damages to fish gills. The thesis deals with the influence of the water chemistry on distribution of ichthyofauna in the Jizera Mts and gill morphology in brook charr (Salvelinus fontinalis), a dominant fish species of the upper plateau of the mountains. The results show that the species diversity of fish in acidified streams is lower than that in streams without meaningful acidic episodes. Histopathological analyses of gills of brook charr individuals from an acidified stream confirm, that low pH values and high concentrations of Ali have a cummulative effect and lead to degenerative changes on gills. Key words: The Jizera Mountains, ichthyofauna, brook charr, gill morphology, water chemistry, toxic aluminium, acidification
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Vliv původu a podmínek chovu lososovitých ryb na jejich nutriční hodnotu
Urban, Michal
The objective of this thesis is judging the influence of selected factors on nutrient value and exterior indicators of salmonids. These factors are enviroment, rearing con-ditions, nourishment and origin of fish. The context between factors and nutrient value was evaluated by literary sources. Practical part is based on data from feeding test. The feeding test was realised in farm Bušanovice on Autumn 2017. Three diferent feeds were fed to six groups of fish. Experimental feed with mineral component named Klinolipolit and two improted commercially produced feeds. I participated on the chemical analysis of the fish samples. The differences betwe-en groups of fish fed with different feeds was evalueted by results from chemical ana-lysis and data from weight and lenght measurement.
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Vliv původu a strategie chovu na nutriční hodnotu produkovaných lososovitých ryb.
Trybulovský, Filip
In my work, I was dealing with the influence of the origin and strategies of breeding of produced salmonid fish on the nutrition value of the muscle. Rainbow trout, brook trout and interspecific hybrid of Salvelinus alpinus and S. fontinalis were analyzed. Two feed tests were performed. Both tests were carried out in an experimental recirculating system at the Department of Fisheries and Hydrobiology at the Mendel University in Brno. Length-weight parameters of fish were measured, from which individual indices, production and conditional parameters were subsequently calculated. In addition, the yield and viscerosomatic index were determined. The content of fat, proteins and dry matter of the fish muscle was determined and used for nutrition value evaluation. The effect of reduced oxygen saturation (below 70 %) compared to normal oxygen saturation (around 100 %) was also analyzed in the first test. In Test 1, feedstuff Biomar Efico Enviro 920, Focus Plus with the addition of immunostimulants and Advance with a higher proportion of plant components were used. No statistically significant differences in production and conditional parameters, length-weight ratios and yields were registered for these feeds. The highest percentage of fat content in the muscle (7.66 %) was in fish fed Focus Plus. The dry matter and protein content of the muscle was similar. The greatest effect of reduced O2 was noticed in the fat content of the muscle. For a group of fish fed Efico Enviro 920, it was statistically significant (p = 0.03 and 0.042). Yield values were higher in a group with reduced oxygen saturation. This could be the result of lower intake of feed at the reduced O2 and lower amount of internal fat. In Test 2, the largest difference was recorded in the percentage production of fish. The highest increase was achieved by rainbow trout in Var. 1 (238.8 %) and the lowest increase was achieved by brook trout in Var. 4 (122.43 %). No statistical significant differences in production and length-weight parameters were registered. The highest yield was recorded in the hybrid (88.47 %) in Var. 5.
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The effect of selected parameters of stream water on gill morphology of brook charr and the structure of ichthyofauna of the Jizera Mountains
Hušek, Jiří ; Dušek, Martin (referee) ; Švátora, Miroslav (advisor)
The occurrence of ichthyofauna on the territory of the Jizera Mountains (Northern Bohemia, Czech Republic) is limited, besides other factors, by the water chemistry. pH value and pH-related concentration of inorganic monomeric aluminum (Ali) are crucial parameters of the water, determining the survival of fish in streams. Low pH and high concentrations of Ali cause severe damages to fish gills. The thesis deals with the influence of the water chemistry on distribution of ichthyofauna in the Jizera Mts and gill morphology in brook charr (Salvelinus fontinalis), a dominant fish species of the upper plateau of the mountains. The results show that the species diversity of fish in acidified streams is lower than that in streams without meaningful acidic episodes. Histopathological analyses of gills of brook charr individuals from an acidified stream confirm, that low pH values and high concentrations of Ali have a cummulative effect and lead to degenerative changes on gills. Key words: The Jizera Mountains, ichthyofauna, brook charr, gill morphology, water chemistry, toxic aluminium, acidification
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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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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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The verification of the mass induction of triploidy in brook charr in operating conditions.
ŠVAGROVÁ, Kateřina
This bachelor thesis deals with the induction of triploidy in brook trout, Salvelinus fontinalis under farm conditions using a heat- and /or hydrostatic pressure shock. The first part involves the issues of polyploidy in fish, its induction, detection methods of polyploidy and its contribution to aquaculture. The second part deals with the technological process of induction of triploidy and subsequently, with evaluation of the effectiveness of both types of the shock upon ploidy level determine by flow cytometry. In this experiment, heat shock induced 80% of triploids in contrary to the hydrostatic pressure shock inducing triploidy in 100%. The pressure shock induced triploidy in brook trout more effectively than the heat shock and provided better operational results. Moreover, pressure shock displayed better fertilization of eggs, higher hatchability, and also higher percentage of triploids.
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Effect of alternative feed on content of omega 3 fatty acids in fish muscles
KREJSA, Jakub
The aim of my bachelor thesis was to evaluate the effect of fish oil substitution for rapeseed oil in the feed on the fat content and fatty acid composition in the flesh of Brook trout (Salvelinus fontinalis) in the finishing feeding technology. The experiment was conducted in 2012 for the period of 135 days. The individuals of Brook trout were divided into four groups. The first two groups were fed with the feed containing only rapeseed or fish oil. The feeding of the remaining two groups was divided into two phases. In the first phase the fish oil was partly replaced by the rapeseed oil. In the second phase the fish oil was replaced by the feed which contained fish oil only. It was proved that a half replacement of the fish oil with the rapeseed oil does not influence the content of fat in the flesh of Brook trout. We observed that the fish had the higher content of MUFA and n-6 PUFA and lower content of n-3 PUFA, DHA, EPA and n-3/n-6 with increasing period where the feed with rapeseed oil was served. Following application of the finishing feeding technology with the use of feed with fish oil had the opposite effects. Furthermore, the dilution model was proved to be highly reliable for the prediction of the fatty acids composition. Based on these findings, it is possible to predict changes of fatty acid composition in the flesh of Brook trout as well as to predict how long is needed to apply finishing feeding to reach required content of EPA+DHA or n-3 HUFA.
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