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Predictive models in survival analysis
Hadwigerová, Michaela ; Vítek, Martin (referee) ; Škutková, Helena (advisor)
With ever-new methods of treatment in health care occures a requierement of comparing these new methods to the old methods in some effective way. This is particularly important for the further development of these methods. However, data that describe these facts could not be processed by normal procedures and therefore was in the field of statistics to create a new kind of methods. They are known as predictive models of survival analysis.
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Water temperature influence on the success of intensive farming of burbot (Lota lota L.)
CHOTĚBORSKÝ, Michal
The aim of this work was to realize the first intensive rearing of juvenile fish of burbot in the Czech Republic (TL = 165.79 +- 18.87, W = 32.91 +- 10.27 g) in recirculation aquaculture system (RAS) at different water temperatures. A total of 9 tanks were used in the three separate RAS systems. For a period of 12 weeks survival (S), specific growth rate (SGR), feed conversion ratio (FCR) and the condition of the fish (FC) was observed at 3 week intervals. The best values of survival (98 +- 0.4%) were achieved in burbots kept at a water temperature of 15 ° C. Survival in the group of fish kept at a water temperature of 18 °C did not statistically differ from the group of fish reared at 15 °C and 21 °C. The SGR value for the fish at a water temperature of 15 °C was (0.7 +- 0.09%.d-1) at 18 °C the SGR value was (0.45 +- 0.1%.d-1) and fish kept at a water temperature of 21 °C reached SGR values of 0.33 +- 0.04%.d-1. The best FCR values (1.27 +- 0.35) were reached also in the group of fish kept at 15 °C. For burbot kept at a water temperature of 21 °C, the FCR value was 2.78 +- 1.17. Based on our results we can conclude that the most appropriate water temperature for rearing juvenile burbot was 15 °C.
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Growth and survival of pearl mussel (Margaritifera margaritifera) for bioindication
NIEDLOVÁ, Eva
Growth and survival of juvenile pearl mussels (Margaritifera margaritifera Linnaeus, 1758) "in-situ" indicates suitable habitats for their rearing and subsequent reintroduction. Six streams in Aš region (Rokytnice, Lužní potok, Pekelský potok, Újezdský potok, Perlový potok, Bockbach) including 15 profiles were evaluated throughout the season (1. 6. 31. 8. 2015). One year old pearl mussels (n = 580) sized from 700 1400 ?m. Mean survival of pearl mussels was 63 % in all streams. Mean absolute growth increment attained 755 ?m throughout the season. Growth of pearl mussels (1+) was positively correlated with the water temperature (R2 = 0,1084). Both the highest survival (70 %) and the highest absolute growth (1027 ?m and 997 ?m) of pearl mussels was determined on localities in Bockbach (Bockbach 11 and 1). In contrast to Bockbach 11 and 1 mean survival (28%) and absolute growth (304 ?m) was the lowest in Lužní potok 2. Survival rate of two years old pearl mussels was higher than that of one year old pearl mussels. Both of these age categories grew similarly.
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The optimization of transfer Northern whitefish larvae (Coregonus peled) on complete feed mixture.
PITHARDT, Tomáš
In this work was tested optimal rearing protocol for Northern whitefish larvae in two experiments. Both experiments lasted for 34 days. In the first experiment the effect of feed particle size on the survival and growth were tested in Northern whitefish larvae with initial body weight of 3.01 +- 0.48 mg. Larvae were weaned from live feed 10th, 15th, 20th, 25th and 30th day after hatching when co-feeding was took for 3 days before the weaning. In the first experiment were tested particle size of 100 micrometers and 300 micrometers. Groups weaned 20th, 25th and 30th with 100 micrometers feed and groups weaned 25th and 30th with 300 micrometers feed had similar final survival (without significant differences). The best growth (final weight 39 +- 12 mg) had group weaned 30th day after hatching using particle size of 300 micrometers. In the second experiment the effect of length of combined feeding (co-feeding) on the survival and growth were tested in Northern whitefish larvae on a unit weight 3.01 +- 0.48 mg. Co-feeding lasted for 1, 3 or 6 days before the weaning. Larvae were weaned from live feed 10th, 15th, 20th, 25th and 30th days after hatching. Groups weaned 10th, 15th, 20th, 25th and 30th had similar final survival (without significant differences). But the best growth (final weight 37 +- 15 mg) reached group weaned 30th day after hatching with combined feeding for one day. Groups weaned 20th, 25th and 30th had similar final body weight (without significant differences). There was no observed effect of co-feeding duration on survival and growth.
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The effect of feeding frequency on feed intake and growth for Peled whitefish (Coregonus peled) in intensive aquaculture.
DOFEK, Jan
Frequency influence of animal feed has been tested (6×, 4×, 2× and 1× per day). Food income and new arrival experiment was repeat in three phases after every 21 days. Fish age after 124 - 187 days from the beginning till the end of the experiment. Average weight in all tanks was 1.86 + - 0.5 g in first experiment phase (0. 21. days). At the end of first experiment fishes with the biggest weight were the one with frequency influence of animal feed 6 times a day. Individual weight at the end of first fishing was 4.21 + - 1.31 g (6× a day), 3.74 + - 1.24 g (4× a day), 3.6 + - 0.46 g (2× a day), 2.89 + - 1.29 (1× a day). The best growth group become group with frequency influence (6× a day and 4× a day) and on the other hand group with the smallest growth was the group with frequency influence (1× a day). Fishes achieved weight of 15.9 + - 4.5 g (6× per day), 15.1 + - 4.9 g (4× per day), 12.19 + - 5.4 g (2× per day), 5.54 + - 4.05 g (1× per day). Chance of survival (96 %) was the best in group with frequency influence of animal feed (4× a day) and the last (89 %) was the group with frequency influence (6× a day). The highest rate of heterogeneity (74 + - 9 %) was in third phase of experiment in fish group with frequency influence (1× a day) as compared to group (28 + - 2 %) with frequency influence of animal feed (6× a day).
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The effect of temperature on feed intake and growth of peled (Coregonus peled) in intensive culture.
VÁLEK, Pavel
The effect of water temperature within the range from 13 to 25 °C was tested on two weight cohorts of fish (age 74 and 230 days post hatch) during two subsequent growing experiments. Significantly better growth rate within the temperature range from 19 to 22 °C was observed in younger fish (initial body weight 0.60 +- 0.04 g). The mean individual weight at the end of the experiment was followed 5.19 +- 1.59 (13°C), 8.16 +- 2.08 (16 °C), 9.78 +- 2.50 (19 °C), 9.06 +- 2.75 (22 °C) and 4.70 +- 2.13 g (25 °C). Significantly lower survival (29.6 +- 6.3 %) was monitored in fish reared at 25 °C. Significantly higher growth heterogeneity (CV 50.1 +- 5.1 %) was observed in fish reared at 25 °C in comparison with the other groups. Significantly better growth rate within the temperature range from 16 to 22 °C was observed during second experiment on older juveniles (initial body weight 13.7 +- 2.9 g). Final mean body weight in appropriate group was observed as followed 25.2 +- 6.8 (13 °C), 30.3 +- 7.1 (16 °C), 29.7 +- 8.0 (19 °C), 30 3 +- 8.8 (22 ° C) and 23.9 +- 5.5 g (25 °C) at the end of the experiment. Fish reared at temperatures 22 and 25 °C showed significantly lower survival rate (70.8 +- 18.8 and 40.8 +- 6.3 % respective) in comparison with the other groups.
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The impact of interspecific hybridization on fitness of Sturgeons
ŠACHLOVÁ, Hana
Sturgeons (order Acipenseriformes) are supposed to be one of the oldest groups of vertebrates still living on our planet. Moreover, their polyploid ancestry makes them very susceptible for interspecifc hybridization. These interspecific and intergeneric hybrids have been already described in nature as well as in captivity. Nevertheless, the fitness of sturgeon hybrids in comparison with pure species has not been studied yet even though it can have significant impact on sturgeon aquaculture production. The main goal of this study was to investigate and compare reproductive features (fertilization rate and hatching rate), survival rate and growth rate of artificially produced hybrids of Siberian sturgeon (Acipenser baerii) and Russian sturgeon (A. gueldenstaedtii) with their pure parental species. The experiment was performed till 262 day after hatching. It was supposed that these observed features could have significant impact on fitness of analyzed individual/groups. The highest reproductive features had hybrid between Siberian sturgeon (Acipenser baerii) females and Russian sturgeon (A. gueldenstaedtii) males while purebred group of Russian sturgeon displayed the lowest values of fertilization and hatching rate. At the beginning of the experiment, the highest survival rate was shown by purebred groups of Siberian sturgeon (Acipenser baerii) and Russian sturgeon (A. gueldenstaedtii), but this trend were slightly changed after 37th day post hatching. At the end of the experiment, the lowest value of survival rate was shown by purebred group of Russian sturgeon (A. gueldenstaedtii). Similarly, the lowest growth rate was also owned by purebred group of Russian sturgeon (A. gueldenstaedtii). In contrast, the best total growth rate was observed for hybrids between Russian sturgeon and Siberian sturgeon (A. geuldenstaedtii × A. baerii ) even though they grew slower until 101st day after hatching. Therefore, given the evidence discussed, this kind of hybrid could be suggested for intensive aquaculture and might be also suitable for polycultures stock. Finally, breeding of sturgeon hybrids might be seen as an effective alternative to pure species in sturgeon aquaculture, but suitable kind of hybrid must be selected.
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Optimization of harvest of juveniles of pikeperch (\kur{Sander lucioperca}) taken out of ponds and following ability of the fish to adapt to system RAS
HAMPL, Jan
Within my bachelor thesis I have been trying to resolve the possibilities of optimization of harvest of juveniles of pikeperch (Sander lucioperca) taken out of ponds, and continuously I have been tracking the ability of the fish to adapt to system RAS that is applied at the experimental fish culture facilities at FROV JU. Working at the fish harvest it has shown me to be important to synchronize the work of every one of the assistants during the individual activities. The fish have been harvested in a very short time and carefully taken to already prepared transport boxes. We checked the most important parameters for the quality of water, its temperature and oxygen saturation. The mortality of the fish during the harvest and transport did not get over 2 %. Just after the transport to experimental fish culture facilities at FROV JU, to the system RAS at Vodnany, the harvested fish has been placed to 9 tanks for the weaning period. Each out of three ponds always received three tanks of harvested and adapted fish. The experiment at RAS has been divided into three parts. First part has been about the weaning period of the fish to the RAS system and the artificial food. The results were very satisfying. I have been following these parameters: SGR, FCR, increase of biomass, survival and cannibalism at the tanks. The level of survival from the pond Rohlíček has been around 83,6 %, the pond Bejkovna 69,7 % and Horažďovice 4 the level of survival was 71,8 %. After finalizing the weaning period we did biometry for 37 of selected representatives. Second part has been the 1st post-weaning period. Here I focused at the parameters such as SGR, FCR, increase of biomass, survival and cannibalism at the tanks. The level of survival from the pond Rohlíček has been around 84,17 %, the pond Bejkovna 83,83 % and Horažďovice 4 the level of survival was 82,83 %. After finalizing the 1st post-weaning period we did biometry for 37 of selected representatives. Third part has been the 2nd post-weaning period. Here I focused at the same parameters as above such as SGR, FCR, increase of biomass, survival and cannibalism at the tanks. The level of survival from the pond Rohlíček has been around 87,5 %, the pond Bejkovna 88,17 % and Horažďovice 4 the level of survival was 87,17 %. After finalizing the 2nd post-weaning period we did biometry for 37 of selected representatives, the experiment was evaluated and pikeperch juveniles were sold to the French company Asialor.
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