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Možnosti intenzivního chovu hlavatky podunajské (\kur{Hucho hucho}) v RAS
MAREŠ, Michal
This bachelor's thesis deals with the possibilities of breeding Danube salmon in the RAS, and also deals with the combination of breeding Danube salmon with rainbow trout. The fish were divided into three groups, with each group reared in three tanks. The first group was a monoculture of Danube salmon, where 160 Danube salmon with an average weight of 432.37 ? 116.01 g were put into each tank. The second group was a monoculture of rainbow trout, where 160 rainbow trout with an average weight of 253 were put into each tank. 27 ? 61.77 g. The third group was a biculture of Danube salmon with rainbow trout, where 80 trout with an average weight of 250.74 ? 61.91 g and 80 Danube salmon with an average weight of 435.04 were placed in each tank ? 119.29 g. The experiment lasted 84 days at an average temperature of 17.43 ? 0.51°C (7:00) and 17.16 ? 0.56 °C (15:00), control refishing and re-weighing was done every 28 days. At the beginning and at the end of the experiment, several pieces of fish from each group were dissected to calculate organosomatic indices, and biometric measurements were made, where the total body length of the fish (TL), the standard body length of the fish (SL) and the weight of the fish (BW) were determined. After the end of the experiment, the production markers (TL, SL, BW, FC, CVBW, SGR, FCR, WG, FE and SR) and organosomatic indices (SSI, HSI, IPF and GSI) were evaluated. In all production markers rainbow trout achieved significantly better values than Danube salmon in both farming methods. Rainbow trout dominated the biculture, using the presented feed more efficiently at the expense of the Danube salmon, as it was more aggressive and active during feeding. According to the results of the organosomatic indices, once again rainbow trout prospered best in both methods of farming. There was a marked difference in the index of intraperitoneal fat (IPF) between Danube salmon and rainbow trout in biculture. The Danube salmon in biculture achieved a better result than the rainbow trout only for the gonadosomatic index. There was a difference in the spleenosomatic index (SSI) for both species. The SSI value was highest in the Danube salmon in the monoculture, which indicates that the Danube salmon in the biculture was more limited in its food source.
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Assessment of the state of the environment with regard to the content of risk elements in fish bodies
Jonášová, Simona ; Zlámalová Gargošová, Helena (referee) ; Komendová, Renata (advisor)
The diploma thesis deals with the study of the content of potentially toxic elements in fish bodies in the Jihlava River. The biological samples were first transferred into solutions by microwave digestion. Afterwards, the potentially toxic elements Cd, Cr, Cu, Hg, Ni, Pb, Zn in muscle, heart, liver, genital organs, gills and intestine were determined by AAS. A total of 20 fish samples were analysed. In european chub and common bream, the concentrations of elements decreased in the order Zn > Cu > Ni > Cr > Hg > Pb > Cd. In rainbow trout, common nase, common carp, european perch and common roach, element concentrations decreased in the order Zn > Cu > Ni > Cr > Hg > Cd > Pb. In northern pike the following decreasing trend was found: Zn > Cu > Hg > Ni > Cr > Cd > Pb. The assessment of the condition of the watercourse was made according to the individuals that were assumed to have been present in the Jihlava River for more than 1 year. According to these fish species, the contamination of the aquatic environment with elements Cr, Cu, Hg and Ni was demonstrated. All fish samples except sample 8 (perch) were assessed as suitable for consumption.
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Aplikace nanobublin ozónu v intenzivní akvakultuře
KONONOV, Maksim
The aim of this bachelor thesis was to test the effects of different ozone nanobubble concentrations (O3NB), as a new perspective method of water disinfection in aquaculture, on early ontogeny (the embryonic and larval period) of rainbow trout (Oncorchynchus mykiss) in a hatchery with a pond water (i.e. organically polluted water) source. During this work, two experiments with various O3NB concentrations ranging from 192 +- 40 to 610 +- 122 mV ORP (group 1: 192 +- 40, 2: 277 +- 104, 3: 392 +- 134 a 4: 610 +- 122 mV) in combination with two different husbandry treatments (with/without removal of dead eggs and individuals) were conducted. In the first experiment (N, groups 1-4 N), unfertilized eggs and dead individuals were not collected, in contrast to the second experiment with collection of dead individuals (S, groups 1-4 S). Testing of the above groups (1-4 N/S) was performed in four replicates (aquariums A, B, C, D). Hatching rate was higher in all tested groups of the experiment S. The highest hatching rate (approximately 75 %) was observed in groups 1S, 2S and 3S (ORP 192 +- 40 to 392 +- 134 mV ORP). Fish mortality rate was higher in all groups tested during the experiment N. The highest fish mortality rate (higher than 75 %) was observed in all groups 3N and 4N/S (ORP 392 +- 134 to 610 +- 122 mV). At hatching, the yolk sac volume negatively correlated with O3NB concentration during both experiments. The yolk sac (as an energy source) was faster fully absorbed in fish reared in groups with lower O3NB concentration in comparison with the highest O3NB treatment, when the absorption was markedly slower. The total body length of fish was significantly affected by O3NB concentration during both experiments. The slowest growth was recorded in group with the highest O3NB concentration (ORP 610 +- 122 mV) compared to other groups (ORP from 192 +- 40 to 392 +- 134 mV). The microbiological analyses showed decreasing amount of water microorganisms with increasing O3NB concentration. In summary, the O3NB concentrations in range ORP 192 +- 40 to 394 +- 134 mV), ideally in combination with treatment S, can be recommended for rearing of early stages (embryos and larvae) of rainbow trout. Further research on O3NB in aquaculture is highly required, as there is still a lack of information regarding this perspective technology.
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The state of commercial aquaponic farms in the Czech Republic
VONDRUŠKA, Vojtěch
The aim of this thesis was to conduct a literature search focused on the issue of commercial aquaponic systems and to analyse commercial aquaponic systems in the Czech Republic. In the second part of the thesis the shortcomings of the commercial aquaponic system in Řisuty were identified and described in detail. In cooperation with Aerolux s.r.o., one of these systems was rebuilt, optimized, and experimentally compared with one of the original systems.
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Výhody a další perspektivy využití smíšené obsádky pstruha duhového (Oncorhynchus mykiss) a mníka jednovousého (Lota lota) v podmínkách intenzivní akvakultury
PROFANT, Vít
This diploma thesis was focused on the culture of rainbow trout (Oncorhynchus mykiss) in combination with burbot (Lota lota) in the Recirculation Aquaculture System (RAS). Production growth indicators, the amount of accumulated undissolved substances and their chemical analysis were compared. In addition, indexes, biochemical analysis and oxidative stress were compared between the experimental groups of burbot. Three groups were tested in the three repetitions. The first experimental group (70/30) contained 70 pieces of trout and 30 pieces of burbot, in the second group (85/15) there were 85 pieces of trout and 15 pieces of burbot and in the last third group (100/0) there were 100 pieces of trout and 0 pieces burbot. The experiment lasted 77 days and control overfishing and weighing, including collection of accumulated undissolved substances, took place on days 21, 42, 63, and 77, when the experiment was terminated. At the beginning and at the end of the experiment, the total length (TL), standard length (SL) and weight (W) were measured for both species. The average water temperature was 17, 91 ? 0.48 ° C and the light period was 12L: 12D, with an average light intensity of 150 lux. Almost no mortality was reported for rainbow trout, but for burbot the mortality was 10% in the group (70/30) and 24.4% in the group (85/15). The SGR for rainbow trout was the significantly highest in the group 70/30 in I. and II. experiment period. The FCR value occurred at the end of IV. period to decrease 0.2 in group 70/30 compared to group 100/0, but there was no statistical difference. Based on data from this experiment regarding biomass and weight of individual fish, rainbow trout has clearly outgrown burbot across all periods. The same result was seen for TL, SL, W and Fulton's condition factor (FC). In the group (70/30), the amount of accumulated undissolved substances in one day was statistically significantly reduced at the end of III. and IV. experiment period. The same result was obtained for the relative amount of undissolved substances in relation to the feed ration used. According to the chemical analysis of the collected undissolved substances, there was a significant reduction in the absolute amount of dry matter and organic dry matter in IV. experimental period. The reduction of the absolute amount of phosphorus and the improvement of its retention based on the relative amount of total phosphorus in the undissolved substances with respect to the amount of feed was confirmed at the end of III. and IV. period in group 70/30. 93 There were significant differences in burbot between groups 70/30 and 85/15 in spleen somatic index, oxidative stress in the intestine, and phosphorus levels in blood plasma. These values were higher in burbot in the group (70/30), indicating that burbot in this group were more limited by the food source. According to the mentioned results, the 70/30 group was considered like the most advantageous in comparison with the other tested groups with regarding to the amount of collected undissolved substances and nutrient retention. On the other hand, in terms of welfare and physiological condition of the burbot, the 85/15 group was better evaluated compared to the 70/30 group. In general, burbot can be considered as a new potential species according to this testing in order to more diversify of freshwater aquaculture.
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Marking of rainbow trout with Alizarin
Halačka, Karel ; Mareš, J. ; Poštulková, E. ; Malý, O.
Method of using alizarin red (ARS) for mass-marking of rainbow trout was verified and optimized. Based on the results, it was possible to create methodological recommendations for marking individuals of rainbow trout using ARS: 1. Marking can be used shortly after hatching (around 14 days) since the fin rays are sufficiently developed or calcified. The standard application time and solution concentration (1 hour, 150 mg/l) can be used if the expected detection time of marker is around 4-5 weeks. It is necessary to increase the application time on 3 hours in order to distinguish individuals 2-3 months after marking. There was no evidence of a negative effect of the dye on rainbow trout individuals (mortality) or a change in chemistry (pH, conductivity, oxygen saturation of water) within standard concentrations and application time and economic parameters. The use of Alizarin red can significantly reduce financial (around 1 CZK/individual) and time requirements for fish marking. When compared with other types of marking, costs can be reduced to 10 percent (or less) and time-consuming (meaning labor costs) can be reduced to several percent. Another advantage that is difficult to quantify is benefit from information obtained by marking on the farms.
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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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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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Morphological differences in farm groups of salmonid fishes
Halačka, Karel
The aim of this study was examination of a influence species/line and stock conditions. This paper record first results form three groups of salmonid fishes – rainbow trout (from Italy and Denmark) and brook trout hybrides (S. fontinalis x S. alpinus). There were choosen morphological parameters observed – body contruction, weigth of intestine organs, epidermal and gill structure and erythrocyte size.
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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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