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Vliv délky a způsobu transportu jiker na jejich líhnivost u hlavatky obecné (Hucho hucho)
BERÁNEK, Lukáš
The success of transporting both unfertilized and fertilized artificially stripped ova of huchen from the farm for up to 5 days was tested. A mixture of ova from 8 females was divided into two parts. The first part was inseminated with artificially stripped sperm (a mixture from several males) on-site (1 hour after stripping), and after rinsing the fertilized ova with water, it was placed in water in a plastic sealable container. The second part of the ova, along with the ovarian fluid, was not inseminated with sperm and was placed in another identical container. Both containers were stored in a thermal insulation box for the following 5 days, including transportation from the site of artificial stripping to the incubation site. The mixture of collected sperm from 5 males was stored in syringes in a separate isothermal box at a temperature of +4°C. Both thermal insulation boxes were placed in the luggage compartment of a passenger car for 5 days. For the ova transported in water, the water was exchanged twice a day. Throughout the first day, both the ova and sperm were transported from the site of artificial stripping to a distance of 350 km to the incubation site. In the following days, the car was driven three times a day for at least 0.5 hour each time to simulate vibrations occurring during transportation. The ambient temperature for the ova during transportation was maintained at 10°C. Samples of both fertilized and unfertilized ova were taken at one-day intervals from the artificial stripping, and after counting and fertilization of the ova with transported sperm, they were rinsed and placed in small incubation dishes with separate water inflows and perforations allowing water flow and preventing the escape of subsequently hatched embryos. Thirty ova were always placed in each variant, with 3 repetitions in all variants. The incubation dishes were placed on the bottom of a shallow flow-through channel supplied with water from a recirculating system with cold-water fish farming. The average water temperature during incubation was 12.8°C. Mortality of the ova was monitored during incubation, white unfertilized or dead ova were removed, and hatching of the embryos was recorded. In the first variant, after stripping the fertilized ova transported in water for one, two, or three days, a hatchability of 32.2 ? 21.1%, 27.8 ? 10.3%, and 33.3 ? 32.1%, respectively, was achieved. After simulated transportation for four and five days, the hatchability decreased to 21.1 ? 1.57% and 15.6 ? 8.3%, respectively. The differences between all the aforementioned parameters are not statistically significant. In the second variant, with unfertilized ova transported in ovarian fluid, a comparable hatchability (34.4 ? 11%) was achieved after one day of transportation, as with fertilized ova transported in water for one to three days. Unfertilized ova transported in ovarian fluid for a longer period (two and three days) showed a statistically significant decrease in hatchability to 7.8 ? 8.8% and 2.2 ? 1.6%, respectively. A 100% mortality rate was found for ova transported in unfertilized ovarian fluid for four and five days. No differences were found in the length of the incubation period due to different methods or lengths of ova transportation. The experiment demonstrated the feasibility of using transportation of fertilized ova in water for several days, with transportation of fertilized ova in the aquatic environment being preferable.
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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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Citlivost plůdku hlavatky obecné (Hucho hucho) k anestetikům Eugenol, MS-222 a 2-fenoxyetanol.
KAREŠ, Martin
This diploma thesis, in the introduction, summarizes the known information about anesthesia with the physiological effect of anesthetics on fish, including a description of the various stages of anesthesia. The following are the detailed characteristics of the anesthetics used (Eugenol, MS-222, 2-phenoxyethanol and Propiscin) and describes the biology and breeding of the studied fish species - Hucho hucho and related species. The practical part of the work deals with the assessment of the influence of individual anesthetics (Eugenol, MS-222, 2-phenoxyethanol and Propiscin) on the onset of individual phases of anesthesia (2, 3a, 3b, 4) and the disappearance phase (3b, 3a, 2,). Unless otherwise stated, the average piece weight of the experimental subjects used was in the range. In the case of the anesthetic Eugenol, the effect of temperature (in the range of 5-15°C) and the concentration of the anesthetic bath (in the range of 0.02-0.04 ml.l-1) and the effect of different fish sizes (in the case of 3 groups in the range of average piece weight 4-353g, at a temperature of 10°C and an anesthetic concentration of 0.03 ml.l-1). The efficacy of the anesthetics MS-222, 2-phenoxyethanol and Propiscin was monitored only at 10°C, each at 5 different concentrations (MS-222 at a concentration of 60-140 mg.l-1,2-phenoxyethanol at a concentration of 0.40-0.60 ml.l-1 and Propiscin at a concentration of 0.5-1.5 ml.l-1). Prior to the actual experiments, the fish were adapted for several days to the temperatures at which the monitoring was performed, the day before the actual experiments the fish were not fed. The duration of the experimental fish's stay in the anesthetic bath was always 10 minutes, after which the fish were immediately transferred to a container of clean water of identical temperature and their observation was continued. The achieved results of the onset of individual phases of anesthesia and its fading in individual variants of the experiment are characterized by the average length of time in seconds and the standard deviation. In most cases, the highest onset times of anesthesia were 5°C and 7.5°C. The lowest values of the onset of anesthesia were 12.5°C. The average values of anesthesia fading decreased with higher temperature in most cases, but with higher concentration the onset of fading phases prolonged. The onset of the individual phases of anesthesia and fading were influenced by concentration, temperature, and weight. Orientation test of anesthetics MS-222, 2-phenoxyethanol and Propiscin at 10°C. The mentioned anesthetics showed the same trend, a gradual decrease in the onset of the anesthesia phases with increasing concentration. In the case of MS-222, 20% mortality was monitored at a concentration of 140 mg.l-1. Propiscin shows a significantly longer time for anesthesia to subside at a concentration of 1 ml.l-1. In the monitored size categories at a temperature of 10°C and a concentration of 0.03 ml.l-1 Eugenol, there was no clear trend of the dependence of the onset of individual phases of anesthesia on the size of fish.
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