Semiartificial spawning does in fishbastion Cejkovice in the area Ostrov. In the year 2006 was count the produktivity hen fish in a pond 7. After incubation was monitored intensity growth rate fingerling in fingerling pond, next species and size variability natural food and her effect in growth rate. Were writed basic physical and chemistry waters (temperature, pH, content O2). Owing to absence of waters and absence of size fit zooplankton was hunted very little of pikeperch fingerling.

Dans le cadre de la production de nouvelles espèces aquacoles, le sandre, Sander lucioperca, est devenu, depuis plusieurs années, une espèce d’intérêt piscicole en raison de sa valeur économique potentielle. Pour développer et pérenniser sa production aquacole, il est nécessaire de comprendre et maîtriser son cycle de reproduction ainsi que les mécanismes physiologiques mis en jeu afin d’obtenir des œufs et des juvéniles viables tout au long de l’année. Dans cet optique d’optimisation du contrôle du cycle, la dopamine apparaît, chez de nombreux téléostéens dont certains perciformes, comme un inhibiteur de l’axe gonadotrope, via les récepteurs de la famille D2, en bloquant le pulse ovulatoire de LH et l’ovulation. Chez le sandre, le rôle de la dopamine et de ses récepteurs, notamment les récepteurs de la famille D1, est inconnu. L’objet de cette thèse est de déterminer le rôle du système dopaminergique lors des phases finales de l’ovogénèse chez le sandre à travers trois axes principaux : (1) déterminer l’effet du blocage des récepteurs de la dopamine, D1 ou D2, sur la régulation de l’axe gonadotrope et l’induction de l’ovulation en absence et en présence d’une molécule de sGnRHa, (2) définir le répertoire et le profil d’expression des récepteurs dopaminergiques par l’étude du transcriptome cérébral du sandre en période pré-ovulatoire et (3) établir le rôle de la dopamine et de ses différents récepteurs (familles D1 et D2) dans la régulation directe et locale de l’axe gonadotrope aux niveaux cérébral et ovarien. La première partie de ce travail a permis pour la première fois, par l’utilisation d’antagonistes spécifiques des familles de récepteurs D1 et D2, de mettre en évidence un rôle potentiel de la dopamine sur la sécrétion de certains stéroïdes sexuels en période pré-ovulatoire chez le sandre par l’intermédiaire des récepteurs de la famille D1. L’identification de l’ensemble des récepteurs de la dopamine existant chez le sandre nous a permis de confirmer leur expression à tous les niveaux de l’axe gonadotrope (cerveau, hypophyse et ovaires) étayant l’hypothèse d’un rôle de la dopamine dans la reproduction du sandre. Enfin, la dernière partie de ce projet a permis de montrer un rôle régulateur du système dopaminergique, directement au niveau ovarien, sur la production de testostérone par l’intermédiaire des deux familles de récepteurs de la dopamine. L’implication des deux familles de récepteurs a également été mise en évidence dans la production ovarienne de la 17β-estradiol. Au niveau cérébral, seule la famille des récepteurs D2 a été montrée impliquée dans la régulation de l’expression du gène de la GnRH-3. De façon générale, cette étude a permis de mettre en évidence l’implication des récepteurs de la dopamine dans la régulation de l’axe gonadotrope lors des phases finales de l’ovogenèse. Toutefois, des travaux ultérieurs devront être menés pour approfondir les mécanismes physiologiques mis en jeu. D’un point de vue aquacole, les traitements hormonaux à base d’antagonistes des récepteurs de la dopamine ont été inefficaces pour améliorer les performances de reproduction du sandre ce qui n’est pas en faveur de leur utilisation future pour induire l’ovulation chez cette espèce. Ainsi, la mise au point d’autres méthodes d’optimisation sera nécessaire pour continuer à développer la production aquacole du sandre / Pikeperch, Sander lucioperca, is a potential valuable economic fish, making it a species of interest for aquaculture diversification. In the domestication process, controlling and understanding the reproductive cycle is a crucial step in order to produce viable offspring in a synchronous and predictable way. In many teleosts including some perciforms, dopamine inhibits the ovulatory pulse of LH and the ovulation step through D2 dopamine receptors family. In pikeperch, the roles of dopamine and its receptors, especially those belonging to the D1 receptors family, are unknown. For the purpose of the optimization of pikeperch reproduction, we investigated the role of the dopaminergic system during the final stages of oogenesis in this species: (1) by determining the effects of D1 or D2 receptor antagonists alone or in association with sGnRHa on the regulation of the reproductive axis and on the induction of ovulation, (2) by determining the repertoire and the expression profile of the dopamine receptors using a brain transcriptome analysis during the pre-ovulatory period and (3) by evaluating the role of dopamine and its receptors (D1 and D2 families) in the direct and local regulation of the gonadotropic axis at the brain and ovarian levels. For the first time, we showed that the dopamine/D1 receptors complex regulates the sex-steroids release during the pre-ovulatory period, suggesting that dopamine is involved in pikeperch reproduction. Also, we support its involvement thanks to the identification of the dopamine receptors gene expression at the brain, pituitary and ovarian levels. Finally, we showed that the dopaminergic system directly regulates the ovarian testosterone production, through both D1 and D2 receptor families. The involvement of both dopamine receptor families was also highlighted on ovarian 17β-estradiol production. Only the D2 receptor family was shown to be involved on the brain GnRH-3 gene expression. In conclusion, we point out a dopamine receptors implication on the gonadotropic axis regulation during the final stages of oogenesis in pikeperch. However, further studies should be performed to pinpoint the physiological mechanisms behind this phenomenon. From an aquaculture point of view, hormonal treatments with dopamine receptor antagonists appear to be ineffective to improve pikeperch reproductive performances. Therefore, their use to induce pikeperch ovulation should be put into question and the development of alternative methods is necessary to further promote pikeperch production

The object of this thesis is to verify Largemouth bass (Micropterus salmoides) as an alternative species to Pikeperch (Sander lucioperca) for fish farming in RAS (Recirculating Aquaculture Systems). Largemouth bass with its good meat quality is comparable to Pikeperch and with its lower sensitivity to stress related to RAS conditions could expand the number of species used in intensive aquaculture. This experiment was split to two parts. In the first part was documented adaptation of Largemouth fingerlings to RAS conditions and artificial feed. After successful adaptation, the second part was started the main experiment. Only 9-16g form pieces were picked from the fish from the first experiment.) The Fish were divided into four groups: Candát 100%, Okounek pstruhový 100%, Candát mix, Okounek mix in three repetitions to nine tanks with capacity of 600 l. Dimensions of these tanks are 101x100x59,5 cm. Each tank was settled by 700 fish. In mixed groups were 350 of Pikeperch to 350 of Largemouth bass in each tank. Second part of experiment lasted 60 days. During that time different parameters of water quality were monitored. Twice a day oxygen, water temperature and once a day pH, NO2- , NH4- were monitored. Every day feeding dosage and mortality were counted. At the end of the experiment all fish were weighed piece by piece to find out the percentage frequency of each weight category in 1 g step. From each tank after every part of the experiment 33 pc of fish were selected and the biometrics were made. Monitored parameters were TL,SL,W and FC, FCR, SGR were counted. Evaluation of outcome and comparison of researched groups pointed to next findings. Largemouth bass showed a slightly smaller growing ability than Pikeperch in RAS. We have to consider a lower water temperature to the end value 21,5°C in system which was set because of Pikeperch sensitivity to bacterial infection and the optimum water temperature for Largemouth bass to 26°C. The experiment proved a high survival of Largemouth bass in groups Okounek 100% 99,86% survival, Okounek mix 99,81% survival. Pikeperch in groups Candát 100% and Candát mix did not exceed 97% in survival. An interesting finding of this thesis proved a positive influence of Largemouth bass to the growth of pikeperch. The group Candát mix had the best results in all monitored parameters TL,SL,W and FC, FCR, SGR.

Aim of this thesis was to use the ozonisation as a disinfection method for improving of water quality in the intensive fish farms using RAS (recirculating aquaculture system). The main assessed parameter was effect of ozone treatment on fish health and RAS functions and features. Two RAS were used in this study one with use of ozone treatment, one without ozone treatment (control system). There were cultured two different fish species in these two RAS - pikeperch (Sander lucioperca) and European catfish (Silurus glanis). The main reason for use of these two species is that they are perspective species for intensive aquaculture. In the RAS with ozone treatment, two different methods of ozone application were tested - periodical and continual application. The effect of ozone treatment on fish health and conditions was controlled regularly. Ozone treatment had positively affected the survival of both cultured species (pikeperch survival: with ozone = 77.0 % and without ozone = 67.2 %; European catfish: with ozone = 93.1 % and without ozone = 91.5 %). Ozone treatment also positively affected the water chemistry. The greatest difference was observed in CHSKMn: with ozone = 6.4?1.2 mg.l; without ozone = 10.7?1.6 mg.l. The same features were observed in suspended solids: with ozone = 4.3?2.8 mg.l-1; without ozone = 8.17?6.2 mg.l. Appearance of Ichthyophthirius multifiliis and bacterial infection were not affected by ozone treatment. The main result of this thesis and this design of experiment is that ozone treatment had a positive impact on water chemistry in observed RAS and it, however, didn't kill 100% of the fish pathogens.

The object of the thesis is to experimentally find the most suitable method of artificial spawning of pikeprech, using hormonal stimulation of ovulation in females hormonal medication containing HCG. After scraping of the broodstock and after artificial fertilization of eggs obtained experimentally test new methods of artificial stickiness removing of eggs and then evaluate the success of artificial incubation of stripped, fertilized and unstickeness eggs of pikeprech. Experiments that are part of the thesis have been divided into several sub-experiments. In the first experiment was observed effect of different doses of hormonal Chorulon, containing the active substance HCG, the basic indicators of reproductive females. Was evaluated as spawning synchronization, spawning success, the number of spontaneous spawnings, fertility of females and hatching rate of eggs. The used HCG doses were 250, 500, 700 and 1000 IU per kilogram of body weight. All eggs were deprived of stickiness using a mixture of talc and milk. In the second experiment was carried out comparing different types of removes stickiness solutions. Here was evaluated especially time and labor intensity and the influence of various solutions on fertilization and hatching rate of eggs. In this trial was all pikeperch females injected the same amount of HCG hormone 500 IU per kilogram of body weight. Tested solutions was a mixture of talc and milk, just eggs wash water and the solution of various concentrations alkalase. The amount alkalase was 0,5; 1; 1,5; 2 and 5 ml, which are mixed with distilled water, so that the total volume of the solution was 1000 ml. The third experiment was supposed to simulate the pilot plant mass propagation of pikeperch females. All females received the same amount of hormone 500 IU of HCG per kilogram of body weight. All eggs were deprived of stickiness using a mixture of talc and milk. In the last experiment was one of the methods tested, which could limit the number of spontaneous spawning during the artificial spawning of pikeperch. To prevent spontaneous spawning were selected females (all were injected with 500 IU of HCG per kilogram of body weight) sewing genitourinary papilla. The incubation of eggs collected during all the experiments were used Zugské bottle.

The aim of this thesis was to test and compare the effect of four selected and in present commonly used medical treatments on other species of fish in recirculating aquaculture system (RAS). This presented work was divided into two separate experiments dealing with curative baths for fry of pikeperch.The fry was raised in ponds, feeded by natural food, with the intention of adaptating for RAS after a bath. Baths were targeted against parasitic and bacterial diseases by using Bellasav, SAVO Original, formaldehyde and Chloramine T. The curative baths took 30 minutes after which the fish were transferred to clean water where the mortality within 24 hours and the efficacy of the preparation within 24 hours was monitored. In the first experiment were used fish with an average weight of 0.23+-0.05 g and a total lenght of 31.7+-2.5 mm at the age of 35 days. The tested doses were 0.5; 1; 1.5; 2; 5; 10 and 50 ml.m-3 for Bellasav, 1; 5; 10; 20 and 50 ml.m-3 for SAVO Original, 0.5; 1; 1.5; 2.5; 5; 10; 15; 30; 45 and 50 ml.100 l-1 for formaldehyde and 10; 20; 30; 40; 50; 100; 150 and 200 mg.l-1 for Chloramine T. The best efficacy was achieved at the concentration dose 1.5 ml.m-3 for Bellasav. The concentration dose 10 ml.m-3 of SAVO Original only reduced parasitic infection by one degree. An effective dose of formaldehyde was 1 ml.100 l-1 which reduced the parasitic infection by two degrees. The most effective preparation was Chloramine T at the concentration dose of 30 mg.l-1. In the second experiment were used fish with an average weight of 1.6+-0.4 g and a total lenght of 60.4+-3.56 mm at the age of 70 days. The tested doses were 10; 20 and 50 ml.m-3 for Bellasav, 10; 20 and 50 ml.m-3 for SAVO Original, 2.5; 5 and 10 ml.100 l-1 for formaldehyde and 40; 150 and 200 mg.l-1 for Chloramine T. The best efficacy was achieved at the concentration dose 20 ml.m-3 for Bellasav and 10 ml.m-3 for SAVO Original. The most effective dose for formaldehyde was 2.5 ml.100 l-1 which reduced the bacterial infection in fish skin by two degrees. The most effective preparation was Chloramine T again at the concentration dose 40 mg.l-1.

The aim of this master thesis was test, comapre and observe the best density of rotifers (Brachionus plicatilis) for growth and survival of zander (Sander lucioperca) larvae stage in the recirculation aquatic systém (RAS). The secondary experiment tests initial feeding of zander by dint of rotifers and consequently by mix of rotifers and artemia. Main experiment observe effect of different density of rotifers on survive and growth of zander. Other observe parameters such as Fulton´s coeficient, total lenght of fish, weight of fish, etc. Fish was divided into 4 groups with different density of feeding and the control group without feeding. Rotifers has been used in density of 2, 6, 10 and 20 pieces per larva. The best growth in "D" group has been compensate by lower surviving. On the other hand the best ratio of survive has been observe in "C" group, which showed lower growth. The optimal rate of growth and survive has been declared in "B" group, which were feed with dose of 6 pieces rotifers for larva. In the second experiment were observe body changes of zander after initial feeding by rotifers folowed with feeding mix of rotifers and artemia. There were observe successful fulfillment of gas bladder and deformation of fish body and spinal after 40 days of keeping larvae in RAS. In the end of experiment there were also observe defirmations body - for example missing lower jaw, upper jaw or both of them. Spinal deformities occured in the form of scoliosis, lordosis, kyphosis and zig zag distortion. The experiment has shown that unsuccessfully filled gas bladder is closely related to the formation of deformitiy in the zander. Another negative factor that affects the filling of the gas bladder is grease on the surface of the water level, so I recommend installing the grease trap in the fill phase of the gas bladder.

The aim of this study was to induce the triploidy in pikeperch (Sander lucioperca) with use of a cold shock. To induce the triploidy, fertilised egg were (spawning temperature 14,5 °C) submerged in a cold bath at the temperature of 2 °C. Time of initiation was 1; 3; 5; 7 and 10 minutes post activation. The exposure time was 20 and 40 minutes. Ploidy level of freshly hatched larvae was assessed with use of the flow cytometry. In both exposure times, the hatching rate was getting lower with later time of initiation (20 minutes exposure, hatching rate: 58,4-13,4 %; 40 minutes exposure, hatching rate: 28- 9,6 %). Number of malformed larvae increased with later time of initiation and longer exposure time (20 minutes exposure, malformed larvae 0-47,2 %; 40 minutes exposure, malformed larvae 0-58,8 %). None of the tested combination of exposure time and time of initiation led to a population containing 100 % triploid larvae. However, percentage of triploid larvae grew up with longer exposure time and later time of initiation. The best cold shock combination with highest yield of triploids were after 20 minutes long treatment initiated 10 minutes post activation (57,1 +- 14,2 %) and after 40 minutes long treatment initiated 10 minutes post activation (61,9 +- 8,2 %). The most important finding of this study is that cold shock treatment leads to triploidy in pikeperch. To obtain 100% triploid larvae, shorter exposure time and different shock temperature might be applied. It may also eliminate low hatching rate and high appearance of malformed larvae.

Patterns in 0+ fish distribution along longitudinal and depth profiles were studied in five canyon-shaped reservoirs in the Czech Republic. In two canyon-shaped and one shallow well-mixed reservoirs the efficiency of fry trawls was investigated during late summer for juveniles and in one canyon-shaped reservoir the efficiency of ichthyoplankton trawls was investigated during spring for larvae and early juveniles.