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Fish excretion of ammonia under different oxygen environmental conditions
MÜLLEROVÁ, Lucie
The aim of this work was to find out and compare amount of ammonia nitrogen excreted by fish in different oxygen saturation of water. Experiments (preliminary, main and additional) were made with ornamental form of common carp (Cyprinus carpio f. Koi) at Laboratory of Aquatic Toxicology and Ichtyopathology RIFCH in Vodňany. The preliminary (orientation) experiment was made in three different dissolved oxygen concentrations (I. 0,65 - 2,66; II. 2,43 - 5,70; III. 6,40 - 6,50 mg.l-1 O2) and fish production of ammonia nitrogen after 2 hours was I. 24,61; II. 85,29; III. 70,19 mg N-NH4+ per 1 kg of fish weight. The fish were also exposed to different oxygen conditions (hypoxia0,76 - 1,46; normoxia 9,8 - 9,46 mg.l-1 O2) in the main experiment which was repeated six times. Detected production of ammonia nitrogen in recalculated to 1 kg fish weight was 25,01 +- 3,14 mg N-NH4+ by the fish in hypoxia and 32,56 +- 4,08 mg N-NH4+ by the fish in normoxia after two hours of experiment duration. Detected difference was statistically significant (P < 0,05). Haematology and biochemical blood examination of fish which were exposed to hypoxia proved statistically significant increasing number of leukocytes, value of haematocrit, concentration of ammonia and glucose was made in the end of experiment. The additional experiment was repeated five times, the fish were exposed to hypoxia there (0,99 - 1,21 mg.l-1 O2) and the control fish were kept in water with concentration of dissolved oxygen between 7,67 - 9,11 mg.l-1. Statistically significant differences in ammonia nitrogen production were already found out in these groups of fish after two hours of experiment duration and difference increased markedly after 4,5 hours (fish production of ammonia exposed to hypoxia 47,92 +- 4,91 mg.kg-1 and in the control fish 101,53 +- 8,31 mg.kg-1). Production of ammonia by the fish originally exposed to hypoxia almost aligned to production of control fish during 2,5 hours after an aeration had been added to the fish in hypoxia. Production of ammonia nitrogen was 93,38 +- 17,82 mg.kg-1 by the fish originally exposed to hypoxia and 110,13 +- 18,21 mg.kg-1 by the control fish. This difference was not statistically significant yet. The results of experiment proved that fish ability to excrete ammonia from body is closely connected with oxygen conditions in water environment.
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The phosphorus balance in semi-intensive rearing of carp
ŠIMÁNEK, Josef
The aims of this bachelor thesis are (i) to verify the generally recognized fact that supplementary feeding has an effect on the increase in phosphorus concentration in the surface water; and (ii) to explore a potential reduction of wastes by supplementary feeding with thermally treated cereals. The experiment was run in two consecutive growing seasons in the years 2012 and 2013. Four ponds were selected for this study. Cereals were applied as supplementary feed in three ponds: In two of them, thermally treated cereals were applied and in the other one, untreated cereal grains were applied. The efficiency of these feeds was compared with the results from the control pond, where fish stock was not supplementary fed. The results showed that bioturbation had a bigger effect on water quality than the input of nutrients from feeds, since water transparency parameters were statistically different (P < 0.05; in the control treatment compared to the ponds that were supplementary fed (higher value of turbidity and suspended solids, lower water transparency). No significant differences were observed in zoobenthos abundance, although the lowest density was in the control pond. However, no differences in zooplankton density between the control ponds and the supplementary fed ponds were found. On the other hand, differences in productive efficiency (SGR) of both types of feeds were found, which was highest in thermally treated ponds. The fact that the amount of phosphorus depends on the age of fish and bioavailability of phosphorus in feed was confirmed. Thermally treated cereals are economically inexpensive and the use of thermally treated cereals may provide a framework for the sustainable management of carp ponds, resulting in improved phosphorus budget over the entire pond system.
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Cryopreservation of common carp (\kur{Cyprinus carpio} L.) sperm under different freezing conditions
SOCHOROVÁ, Denisa
In the present study, we examined several cryoextenders previously used by several authors and various freezing protocols to determine the relative importance of each parameter on sperm freezing. The effects of controlled seeding and changes in cooling rate at different stages of freezing were also examined. Sperm samples from seven individual carp males were frozen in 0.5 ml straws by conventional freezing. Cooling rates were determined by monitoring the sample's internal temperature. We compared four freezing protocols, which involved placing sperm samples at various levels (1, 3, 6, and 9 cm) above the liquid nitrogen (LN) surface (corresponding to -190, -150, -110, and -70 °C, respectively) for 20 min followed by transferring the samples into LN. Freezing at 3 cm above the LN surface resulted in the highest motility (33 ? 8 %) and velocity (118 ? 9 ?m/s) of spermatozoa after thawing and diluting in swimming medium. We determined that -90 °C is an optimal temperature at which immersing the samples in LN does not affect sperm motility after thawing. The sperm motility of samples immersed in LN before or immediately after the crystallisation point (-16 °C) was 0 %. Motility of spermatozoa cryopreserved with or without a seeding procedure was not significantly different after thawing. Therefore, we hypothesise that supercooling the sample during the conventional freezing procedure is not the main damaging factor during carp spermatozoa cryopreservation.
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The influence of fishery farming intensity on water quality in ponds
KREJČÍ, Filip
The introductory part deals with the history of czech fish farming and there is given further information on selected quality parameters of pond water, which are important and risky in terms of fishery production. The main part of the thesis summarises data from the literature, final reports and RIFCH (The research institute of fish culture and hydrobiology) Vodňany database is processed in a form of tables and graphs for clear presenting of physiochemical properties of pond water, including brief details about the way of fish farming, eventually about other important factors, which could also affect the water quality. The main data source of my thesis were four projects, which dealt with this issue during a relatively long period of time, from the seventies of the last century until the year 2012. The greatest attention was paid to data gained under NAZV QH-82113 project "Careful and effective fish farming with maximal utilization of current trophic potential and keeping of sufficient water quality and fish production" in the years 2008-2012 at experipentals ponds of RIFCH Vodňany. There was a comprehensive set of data gained from semi-intensive conditions, where working multiple times and in a very well comparable and under well documented conditions (size of ponds, water supply, fish farming methods) was possible. Based on some published data and data obtained from VÚRH Vodňany database, it was able to demonstrate a direct influence of the size of initial stocking density on the water quality of ponds (especially the concentration of suspended solids, volume of organic pollutions and the total concentration of a phosphor). Generally, parameters, which often do not comply with legislative requirements, could be described as suspended solids, concentration of oxygen, ammonium, total phosphor and Biochemical oxygen demant (BOD5) and Chemical oxygen demant (CODMn or CODCr) values, whose values are sometimes influenced by factors such as for instance the history of a pond, other than production usage of the pond in the previous period (deponie of waste from livestock production, recreational activities etc.)
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The effect of supplementary feeding of market carp by cereal feeds on water quality
STROUHAL, Jiří
The purpose of this thesis was monitoring the impact of supplementary feeding to selected parameters of water quality (temperature, oxygen, pH, alkalinity, conductivity, turbidity, total suspended solids, chlorophyll a, CODCr, BOD5, TP, P PO43-, TN, N NH4+, N NO3). This experiment took place in storage ponds in Třeboň for 120 days. For the supplementary feeding were used nonmodified wheat, thermally wheat and thermally and pressed wheat. There were chosen 2 storage ponds for every group. Fish were fed 3 times a week. For comparison of results it was deployed a.k.a control where fish were dependent on natural food. It was taken total 12 samples in which were determined chemical and physical properties of water. Only one statistic (p < 0,05) difference was recorded in concentration of oxygen in storage ponds, where fish were fed by thermally and pressed wheat (5,79 + - 1,38 mg.l-1) in comparison with control (7,00 + - 1,73 mg.l-1). Other parameters did not exhibit significant changes among the monitored groups (p > 0,05).
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Susceptibility of Individual Fish Species to Koi Herpes Viral Disease - a research study
KOSTLÁN, Jakub
Koi herpes viral disease (hereinafter referred to as "KHVD") is a dangerous viral disease, outbreak of which was recorded in Israel in 1998 for the first time. Due to exhibitions and international fish trade it spread almost to the whole world in the course of the next 17 years and it caused a loss of many tonnes of both breed and consumption carp as well as it inflicted significant economic losses calculated in the tens millions of dollars. The European Union has added the koi herpes viral disease, due to its hazards, to the list of non-exotic diseases. Since 2008 there is a duty to report this infection in the Czech Republic as well. Koi herpes virus classified in the system of viruses as Cyprinid herpesvirus 3 (CyHV-3) is considered the infective agent. Koi carp (Cyprinus carpio koi) and common carp (Cyprinus carpio carpio) are considered the main species susceptible to KHVD. However, it has been proved that the virus may be also detected in tissues of other fish species and in some of them clinical symptoms may appear. It is of high degree of probability that such fish species may play the role of viral communicants and this presumption has already been proved in some species in experimental conditions. With a view to the fact that koi herpes viral disease is incurable and application of a vaccine is impossible in the Czech Republic, for protection of fish breeding it is crucial to prevent bringing the disease in the territory. Mass fish perish caused by KHVD shall be prevented by strict inspection processes of the imported and exported fish, monitoring of the disease spread and responsible breeders' approach. The major objective of this work was to summarise available information about koi herpes viral disease and susceptibility of the individual fish species to this dangerous viral infectious disease in a form of a research study.
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Vliv rozdílné techniky aplikace krmiva na produkci kapra obecného (Cyprinus carpio L.) v rybničních podmínkách
Weiser, Tibor
The aim of this work was to evaluate and compare the effect of the Carp - Feed feeding system with the feeding by standard way "by hand" at different densities of fish stock (2000 - 6000 pcs per ha) of common carp (Cyprinus carpio L). In the period of 24.4. -- 27.9. 2012 feeding tests in rearing of carp fry (mirror carp) in the ponds system in Milevsko were conducted. The feed mixture with the increased content of nitrogenous compounds at the level of more than 18% was used in the test. According to results, increasing of individual growth was found at 197 g (45%), resp. 52 g (25%) in the higher stocking density when using the Carp - Feed, which is caused by increased growth intensity by 6.1, resp. 2.2% in the relative daily growth and by 0.22%, resp. 0.044% per day in SGR. The production efficiency of food fluctuated in the range of 0.95 - 1.86 in FCR, 0.54 - 1.05 in FCE, 0.45 - 0.92 in FCR / SGR and 1.774 - 2.311% per day in specific growth rate SGR. The influence of feeding method and stock density on length and weight parameters, exterior and on chemical composition of muscle was statistically significant (P - 0.05). There was not proved any significant influence on fitness indicators. According to the observed results, it is suitable to use the Carp-Feed feeding system, but higher food consumption and lower individual weights at higher densities of fish stock have to be considered. That is why the aim of rearing should be set in advance. According to experiment, it is better to choose higher stock density (6000 pcs per ha) when using the Carp -- Feed for reaching the higher production in acceptable individual weight and for maximum yield. The literary review on feeding problems and possible modification of feed is also part of this thesis.
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Ověření možnosti použití netradičních chovatelských postupů v chovu kapra obecného (Cyprinus carpio L.)
Kukačka, Vladimír
A series of four experiments has been made with the aim of monitoring the dynamic of change in the spectrum of fatty acids of common carp (Cyprinus carpio L.). In addition, the experiments also focused on the possibility of targeting changes in order to achieve a better dietary value of carp meat for human consumption. The changes in fatty acid spectrum of carp have been achieved by feeding of linseed and fish oil additions in a short interval, and by relaying fish with progressively decreasing temperature of water environment. From dietary point of view, the submission of feed containing 6 % linseed oil improved the FA spectrum of carp muscle when compared to the standard carp farming technology of cereal feed. The FA muscle fish spectrum, obtained due to the feed starting in early September 2008, endured without any considerable change through early January 2009. The application of fish oil is limited to qualitative composition. Through the addition of oils rich in EPA and DHA in the feed can effectively increase the content of the FA in muscle of carp.
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The use of artificial and semi-artificial spawning in the present breeding of common carp
MARKOVÁ, Aneta
This thesis is focused on the use of artificial and semi-artificial spawning substrates in the current breeding of common carp (Cyprinus carpio, L.) a literature review of this species was processed in relation to reproduction, as well as of the spawning methods (natural, semi-artificial, artificial). Results are drawn from the experimental part (2 spawns: a semi-artificial spawn in the institution for experiments at the Fishery School in Vodňany and an artificial spawn in the fish hatchery at the Research Institute of Fish Culture and Hydrobiology in Vodňany). In both spawns, hormonal stimulation of brood stock was carried out. In the artificial spawning the amount of obtained sex products of individual breeds was assessed. At the same time, a questionnaire survey was conducted at 11 fish-breeding companies engaged in their own production of yolk sac fry. The responses obtained from the survey and findings from the experimental part of spawnings were compared with bibliographic sources which the following conclusions were reached from. It was confirmed that at present a massive carp fingerling production from artificial spawn ensuring optimized conditions dominates over the Dubravius method of semi-artificial spawning which is used only rarely. The production of mirror carp is currently higher than the production of scaly carp. Among the bred mirror breeds the Hungarian mirror carp (M2) prevails, nonetheless it depends on the individual fishery company which form of carp they choose to satisfy the market demand.
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Productive efficiency of modified feed in culture of market carp in the storage ponds experiment at Třeboň fisheries.
MELKA, Václav
The aim of this bachelor thesis was to verify the productive efficiency of thermally and mechanically modified wheat in comparison to the non-modified wheat in experimental fish ponds. The experiment was conducted in storage ponds of Třeboň Fisheries Ltd. and took place along 120 days in 8 rectangular ponds. Four treatments were used: thermally wheat, thermally and pressed wheat, non-modified wheat, and control without feeding. Each treatment was run in duplicate. Fish were fed three times a week early in the morning and in the same part of the storage pond. Every month, fish were harvested and some parametres were recorded (weight, length and fat content). Then, fish were restocked. The results of the productive indicators at the end of the experiment have proved a positive influence of thermal and mechanical modifications on the productive efficiency. The highest productive efficiency was achieved by the carps which have been fed by thermally and pressed wheat: Food convertion ration (FCR) was 2.17 - 0.17; Food Convertion efficiency (FCE) was 0.47 - 0.04; and Specific Growth Rate (SGR) was 0.63 - 0.06 %.d-1. Fish fed with thermally treated wheat reached values for FCR of 2.32 - 0.16; FCE of 0.44 - 0.04; and SGR of 0.60 - 0.06 %.d-1. Finally, the lowest productive efficiency was found at the wheat without any modifications (FCR: 2.38 - 0.10; FCE: 0.43 - 0.02; SGR: 0.58 - 0.07%.d-1). Therefore, thermal and mechanical modifications of wheat are positive modifications to improve production efficiency in market carp farming.
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