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Influence of feeding management on intensive breeding of pikeperch (Sander lucoperca)
KUČERA, Václav
This thesis is aimed on problematics of intensive pikeperch aquaculture and the influence of the feeding by different types of pellets and also different frequencies of feeding during the day. Whole thesis consists of two separate experiments. In the first experiment I tried to evaluate the influence of sinking and floating type of pellets on the growth abilities and production markers of juvenile pikeperch. First experiment was stocked with 8000 pcs of juvenile pikeperch (average weight 21,38g). These fish were kept in controlled conditions for 16 weeks (average temperature of 21,37 ? 0,66 °C (7:00) and 20,77 ? 0,55 °C (15:00), average dissolved oxygen levels of 127,43 ? 2,37 % (7:00) and 117,03 ? 1,14% (15:00) °C, 120 % and initial biomass of 13,42 kg/m?). These fish were fed by belt feeders two types of pellets (floating Skretting Europa and sinking Biomar Effico Sigma) with the same nutrient composition. After 16 weeks all the production markers (SGR, FCR, WG, TL, CF and survival) were examined. Almost all the parameters showed the statistically significant difference in favor of the sinking pellets. Although growth heterogenity turned out to be lower in the group fed by floating pellets. In the second experiment 600 individuals of juvenile pikeperch with average weight of 37,49 g were stocked in tanks. These fish were kept in controlled conditions for 6 weeks (average temperature of 21,37 ? 0,66 °C (7:00) and 20,96 ? 0,66 °C (15:00), average dissolved oxygen levels of 127,43 ? 2,37 % (7:00) and 117,03 ? 1,14 % (15:00) with initial biomass of 13,35 kg/m?). These fish were fed by automatic feeder Imetronic Self Feeder in 3 different frequencies a day (3,6 or 12 batches). Pellets Skretting Europa- 15F were used in this experiment. After 6 weeks of rearing production markers were examined. Growth heterogenity, somatic indexes, and fin erosion were also examined. Also, blood samples were taken. After data analysis no statistically significant difference was found among the production markers in all three groups. Growth heterogenity was proven to be the lowest in the group fed 3x a day and highest in the group fed 12x a day. Organosomatic indexes showed statistically significant difference of HSI (hepatosomatic index). Highest index was observed in group fed 3x a day. During the analysis of the data from biochemical analysis increased levels of albumins and tryglicerids were observed especially in the group fed 12x a day. Simultaneously, statistically significant differences among the amonia levels (lowest concentration in the group fed 3x a day and highest in group fed 12x a day) and glucose (lowest concentration in the group fed 3x a day, two other groups had almost the same level of glucose) levels in plasma were found. As a group with the best results was determined a group fed 6x a day. This group reached satisfying results in production markers (better than group fed 3x a day but slightly worse than group fed 12x a day). Also, lower growth heterogenity than in group fed 12x a day was observed. Group fed 6x a day also displayed the best working lipid metabolism in contrary to the group fed 12x a day which displayed the disorder of the lipid metabolism. Also, the fin erosion was slightly lower than in a group fed 12x a day.
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Rozvoj zooplanktonu v rybnících s produkcí rychlených stádií hospodářsky významných druhů ryb
PECHA, Oldřich
This master thesis was focused on zooplankton development in ponds with advanced fry rearing of economically important fish species. For the purpose of my study, we sampled pond cascade that is managed by Štičí líheň - ESOX, spol. s r.o. in the village Liderovice, near Tábor. In this particular pond cascade, the annual production of advanced fry of economically important fish species takes place, namely pike, pikeperch, carp, tench and grass carp. Importantly, pond cascade is used several times during one growing season, and zooplankton is the main food source of all early stages of rared fish. For the production of advanced fry of fish served 3 ponds, which were released and refilled 2-3 times a season. Fourth pond served as a control stocked with one year old carp throughout the whole season. The water from an upper pond in the cascade served as zooplankton inoculum to a lower pond after the pond harvesting. Statistical analyses showed that the fry of different fish species in ponds lying in the same cascade does not affect the composition of zooplankton after restocking and water refilling. The only difference we noticed was in the treatment with pikeperch, which partially does not share the food base of other monitored species.We also found out, that the occurrence of Cyclops vicinus, Daphnia magna, D. ambigua or D. pulicaria was positively correlated with increased P-PO4 concentrations. We also confirmed that pond ecosystem can effectively retain nutrients from basins and use them for its production. As was shown after a short rain when the measured concentration of total phosphorus in the inflow in our pond system was 0.50 mg/L, on the contrary in the last pond of our cascade we measured values below 0.08 mg/L. High transparency was maintained in the whole cascade throughout the monitoring period, and an adequate economic profit was generated. Such management can be applied to only a few ponds (systems).
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Embryonální vývoj a transplantace primordiálních zárodečných buněk u candáta obecného Sander lucioperca
GÜRALP, Hilal
It is the purpose of this thesis to implement primordial germ cell (PGC) transplantation, one of the new biotechnological reproductive methods, and for this to explain the details that we have to know about embryo development and PGC migration in pikeperch. We provide several specific useful methods such as GFP labelling and blastodisc surgery which are required for efficiency assessment of the transplantation technique. The main results of the publications in the thesis could be informative and useful for generation of germline chimera by using pikeperch. We described pikeperch embryo development to first feeding at 15°C in detail and demonstrated effects of temperature on the rate of embryogenesis to determine temperature limits for slowing development with minimum negative effects on growth and survival rate. We also developed a technique to soften the pikeperch chorion by enzyme in order to remove it by forceps for in depth observation. Additional groups of eggs were fertilised and incubated at different temperatures to document embryo developmental stages, developmental rate, and survival. The optimum fertilisation and incubation temperature was 15°C, with the highest fertilisation, survival, and hatching rates. Embryo development was drastically slowed down at 10 °C, with 45% of fertilised embryos surviving to hatching. Development was accelerated at 20 °C, with a 56% survival rate of fertilised embryos. After the series of experiments to characterize the embryo development of pikeperch, it could be a valuable model percid for research in which flexible incubation temperatures is required. We described the important early embryonic events, namely, yolk syncytial layer (YSL) formation and midblastula transition (MBT) during the blastula stage in pikeperch embryos. The chorion was removed as we described in the first study. The YSL was formed after the breakdown of marginal cells during the 512- to 1k-cell stage. Cell division analysis by 4'-6-diaminido-2-phenylindole (DAPI) staining revealed that transition from synchronous to asynchronous division occurred after 1k-cell stage. Our results indicate that MBT starts after this stage. Next, we performed blastodisc isolation assay to find the competent stage for embryonic manipulation. Embryos were manipulated by using a microneedle every hour from the 512-cell to the sphere stage, and then developmental rates were evaluated at the hatching stage. The highest survival rate was obtained when we performed this manipulation at the 1k-cell stage. These results clearly showed that the MBT is the best stage for transplantation of PGCs or any cells in pikeperch. We described PGC migration and performed blastomere transplantation in pikeperch. PGCs were visualised by injection of synthesised green fluorescent protein (GFP) within the 3'untranslated region (UTR) mRNA of nanos3. GFP-positive PGCs appeared in all embryos at approximately 100% epiboly. Time-lapse imaging revealed the PGC migration pattern from their initial appearance to the location at the gonadal ridge. We conducted blastomere transplantation at the blastula stage. Donor embryos were labelled with GFP-nos3 3'UTR mRNA and tetramethylrhodamine dextran to label PGCs and somatic cells, respectively. Twelve blastomere transplantation chimeras were produced, with eight surviving to hatching. All exhibited donor-derived somatic cells in the developing body. The PGCs from donor embryos were observed to migrate towards the gonad region of the host embryos. Our results indicated that blastomere transplantation can be successfully applied in pikeperch, and these findings may be useful to produce germline chimeras in percids.
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The effect of periphyton on the development of macrozoobenthos in ponds
URBÁNEK, Marek
The aim of this study was to evaluate the effect of two types of artificial substrate enhancing periphyton development on macrozoobenthos community in ponds in which larvae of pikeperch (Sander lucioperca) were cultured to advanced fry. The experiment was divided into two time periods and was performed in twelve ponds in experimental facility of FFPW in Vodňany. In the first time period of the experiment (from the end of April to the beginning of June) there were three different treatments of the ponds established: a substrate from heather, a substrate from geotextiles and a control without any substrate. Each treatment had four repetitions. In the second time period of the experiment (from the middle of June to end of September) the substrate from geotextiles was removed and following options of the pond treatment such as the substrate from heather, releasing of prey fish into the four ponds and no support of periphyton (a control) were applied. In the course of both experimental time periods samples of substrate and bottom macrozoobenthos were taken in ponds each 3 weeks. According to statistical analysis, significantly higher abundance of macrozoobenthos was found on the substrate from heather in comparison to substrate from geotextiles (F (1, 6) = 12.897, p = 0.011). Mean values of the species abundance and the species biomass were always higher in the bottom macrozoobenthos than in the substrate macrozoobenthos. Mean values of diversity index were always higher in the substrate macrozoobenthos than in the bottom macrozoobenthos. The effect of the pond treatment on development of the bottom macrozoobenthos was not confirmed. The influence of the geotextiles on enhancement of fish production was rather negative. The substrate from heather increased the production of advanced pikeperch fry at 7 - 21 %, in the first time period of the experiment. Thus, next further research in this field can be beneficial regarding effective culture of some important fish species.
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Induction and optimalization out-of-season spawning of spawners pikeperch (Sander lucioperca)
VLČEK, Jakub
In total, 21 pairs of pikeperch brood stock were divided into three groups and used during two out-of-season and one seasonal semi-artificial spawning. The only differences among these three groups were the length of cold water period (CWP) and spawning date. Group of earlier spawning (A) CWP = 122 days, Group of normal spawning (B) CWP = 149 days, Group of late spawning (C) CWP = 223 days). Dates of spawnings A 11.3., B 26.4., C 13.6). There were observed and assessed the main production parameters such us latency, successful spawning, fertilisation and hatching rate etc. in each group and spermatozoa quality (sampled one day after the observed spawning). In Group A and B, 100 % of fish successfully spawned. Fertilisation rate was 59.4 % (Group A) and 80.3 % (Group B). Much worse results were obtained in Group C. Only 42.9 % of fish spawned and the fertilisation rate was zero. There was no difference among the three groups in spermatozoa quality parameters. It means that the poor fertilisation rate in Group C was caused by low egg quality. According to our results we can say that it is possible to successfully spawn pikeperch earlier (before the main spawning season) with comparable result to the natural spawning season. However, it is necessary to find some better way for female stimulation to provide higher egg quality and subsequently higher fertilisation rate.
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Comparision of rate of pike and pike perch cannibalism in first year of life
SVATEK, Petr
Abstract Larvae of perch (100-200 thousand per ha) were planted into the ponds Bejkovna (1,33 ha) and Kamenný (1,54 ha). Larvea of pikeperch (150 - 300 thousand per ha) into the ponds Hejškův (0,88 ha) and Hadač (2,7 ha). Pond Bagr was used such as an additional data source. The aim of this study was Comparision of rate of pike and pike perch cannibalism in first year of life. There wasn?t observed cannibalism and different sizes of perch individuals in the ponds Bejkovna and Kamenný. Total length (TL) of the fish was 50,5 ? 2,85 mm in the pond Bejkovna and 41,58 ? 1,56 mm in the pond Kamenný at the end of observed period. Average growth rate was 0,86 mm/day in pond Bejkovna and 0,7 mm/day Kamenný. There was also no cannibalism by the perch (TL = 57,2 ? 1,34 mm) from the pond Bagr. It was possible to observe few individuals of roach (Rutilus rutilus) in the digestive tract. The level of cannibalism was 23 % in the pond Hadač and also in the pond Hejškův. The average TL was 31,59 ? 3,89 mm (average growth rate 0,9 mm/day) in the pond Hadač at the beginning of June and 26,83 ? 2,51 mm (average growth rate 0,77 mm/day) in the pond Hejškův. The average TL was 48,7 ? 10,04 mm in the pond Hadač at the end of June. There was observed cannibalism in the pond Hadač at the beginning of the June and also at the end of this month. TL of prey fish was 66,1 and 61,6 % of cannibals TL. There was observed cannibalism in the pond Hejškův until the mid of September. The average TL was 140,6 ? 35,4 mm here and cannibalism was observed in 23 % of cases. TL of prey fish was 54,9 % cannibals TL. The most important thing of the monoculture rearing of perch and pikeperch is sufficient amount of food. This is especially true in the case of pikeperch. Key words: Cannibalism, pike perch, perch
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Optimization of artificial spawning of pikeperch (Sander lucioperca) using HCG and new ways of removing artificial stickiness of eggs before incubation.
BLECHA, Miroslav
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.
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Semiartificial spawning pikeperch and fingerling-scale reading in Fishery Hluboká
MACÁK, Miroslav
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.
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