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Utilization of organism Daphnia magna in ecotoxicity tests
Winklerová, Lucie ; Vávrová, Milada (referee) ; Zlámalová Gargošová, Helena (advisor)
This thesis deals with ecotoxicity tests of selected substances used in agriculture and horticulture. It is focused on the determination of acute and chronic toxicity of selected herbicides. These herbicides are sold commercially, specifically Finalsan (active substance is nonanoic acid), the product of Neudorff GmbH KG company, and Dominator (active substance is glyphosate, isopropylamine salt) by Dow AgroSciences Ltd. Next tested substances are potassium nitrate and sodium nitrate - common agricultural fertilizers. Potassium dichromate was also tested. Potassium dichromate is very toxic for aquatic environment and it is used as the standard in acute tests. Tests were carried out in terms of effects on aquatic systems, due to very good solubility in water of selected substances. The tests were performed on the organism Daphnia magna.
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Impact of fish predation and littoral vegetation on the structure and behaviour of zooplankton
VESELÁ, Jana
The impact of fish predation on zooplankton assemblage was studied in the mesocosm experiment. Presented thesis focuses on the effect of size selective fish predation on species diversity, biomass and body sizes of zooplankton and the impact of fish occurrence on zooplankton behaviour with regard to diel horizontal migration. I also studied a change in some life history traits of zooplankton caused by fish with a special focus on keystone species of freshwater ecosystems Daphnia spp.
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Evaluation of the environmental quality of the Novomlýnský rybník reservoir (cadastral zone Nová Bystřice)
NOVOTNÁ, Barbora
Seasonal variations of zooplankton, zoobenthos, fish assemblage and hydro-chemical and limnological indicators were studied in the Novomlýnský rybník reservoir (PP Homolka Vojířov) near Nová Bystřice in 2014. The results were used for the evaluation of factors influencing the quality of the environment of a small water reservoir. The measurements and samples were taken monthly from April to October (with the exception for June) in the pelagial at the point of the pond maximum depth. The sampling of fish to determine the species present took place once, in April of 2014. At the same time, two measurements and sample taking took place at the reservoir inflow and outflow. The results of this survey could be useful during planning and water management of the reservoir with the aim to restore the environment and increase the range of present large filtering zooplankton, particularly those from the Cladocera family, which are scarce in the reservoir.
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Different effects of planktonic invertebrate predators and fish on the plankton community in experimental mesocosms
ŠORF, Michal
The impact of fish and cyclopoid copepod predation on zooplankton communities was evaluated using large-volume mesocosms (depth 9.5 m; volume 13 m3) in the Římov reservoir (Czech Republic). Two yearling roach and perch individuals introduced into mesocosms represented the fish treatment, which was compared to cyclopoid copepods (initial abundance of 2 ind.L-1) and a control with no initial addition of predators. Our results clearly support the hypothesis that planktivorous fish feeding leads to the suppression of large-bodied cladocerans. In the presence of fish, the cladoceran community changed from a dominance of large-bodied Daphnia spp. at the beginning to dominance by the smaller Bosmina longirostris at the end of the experiment. The overall strong effect of fish over cyclopoid predation suggests the main role of fish predation in the forming of zooplankton communities and in turn impacting phytoplankton biomass in mesocosms.
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Kvalita vody a složení planktonních společenstev vodní nádrže Opatovice
Hylák, Tomáš
The aim of the diploma thesis was a seven month research at the valley waterworks reservoir called Opatovice by Vyškov na Moravě. Taking of the water samples was carried out once a month from two sampling places, which were located on the leeward and windward sides. On the same day these water samples were analyzed at the Fishery and Hydrobiology Department of the Mendel Univerzity in Brno, where there were determined physical and chemical parameters of water, quantitative and qualitative content of the plankton associations. The results were compared with my bachelor thesis: The Development of the Quality of Water in the waterworks reservoir Opatovice, with the results from the previous years, which were provided by the Water Supply and Sewerage company, plc in Vyškov, with the valid legislation of the Czech Republic and with selected waterworks reservoirs situated in the south Moravian region.
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The feeding biology and growth of European weather loach (Misgurnus fossilis)in the first year
KOCIÁN, Pavel
The principal aim of this bachelor thesis is to describe the feeding biology and growth of European weather loach (Misgurnus fossilis). In Introduction, the overview of literary sources is presented and existing publications are documented. The main part of this thesis concerns the experiment itself, based on which the feeding biology and growth of European weather loach in the first year of its life is discussed, with primary accent on food determination and food supply description. In final section, the results of food preference and running growth of fish in various periods of reduction fishing are presented. The results have shown that in the first month, fish feeds dominantly on daphnias, rotifers and testaceas. In the beginning of the following period, the fastest growth of all individuals was observed and fingerling started to prefer water fleas, ostracods and chironomids larvae.
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Diversity of fishpond zooplankton in Javořice highlands region
IŠTOK, Tomáš
It studied the species composition of pond zooplankton selected pond in Javořická highlands, near Nová Bystřice and Slavonice. Sampling was pelagial and at selected locations and littoral ponds. When selecting sites sampled, the emphasis was on the selection of sites with historical, expected or actual occurrence Heterocope saliens that occurs on sites with ponds and bogs around the aquatic environment with lower pH. These sites are usually extensively farmed. Found 69 species (24 Cladocera, 15 Copepoda, 30 Rotatoria). Confirmed the hypothesis that the greatest variety of species of zooplankton found at mesotrophic sites with moderate fisheries management.
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The community of zooplankton in the pools in inundation area of Lužnice river
ŠEBESTA, Roman
This thesis aims to discuss generally the pools of river with a focus on the Upper Lužnice river maiinly on zooplankton communities, which ooccurs in these locations. Regular sampling of communities in different types of river pools better then identify their species and numerous changes during the year. Thesis deal with samplinng techniques and laboratory processing sampples of the zooplankton to.
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Redundant fingerling of perch (Perca fluviatilis L.) in Vír Reservoir and its impact on other trophic levels
VEJŘÍK, Lukáš
The composition and preferences of depth levels and habitats of pelagic fingerling was studied in the canyon-shaped Vír Reservoir during years 2009-2011. The perch (Perca fluviatilis) fingerling was dominant in all three years. The density of fingerling was above the mean in years 2009 and 2010. It was as many as 278 individuals in 100m3(mean is 52 individuals in 100m3). A marked fall on 1,9 individual in 100m3 was registered in 2011. Perch fingerling was mainly observed in metalimnion during the day and also at night, where concentration of oxygen was very low. The highest density of perch fingerling was observed in the middle part within longitudinal profile. A significant difference was found in food composition among the years with high density and low density of fingerling. A predation of carp (Cyprinus carpio) and bream (Abramis brama) was proved during the years with high density of fingerling.
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