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The effect of periphyton on the development of zooplankton communities in ponds
TŘEŠŇÁKOVÁ, Nikola
In my bachelor thesis I studied the development of zooplankton communities in 12 experimental ponds for rearing of juvenile pikeperch (Sander lucioperca). Two different types of substrates were installed in the ponds to support the growth of pond periphyton and the subsequent development of other food organisms with the main aim to increase the production of pikeperch fry. The sampling of zooplankton communities took place at the Experimental Fish Culture and Facility RIFCH, SBU in Vodňany in three-week intervals during the first phase (22/4 - 2/6 2014) and the second phase (16/6 - 8/9 2014) as well. The samples of zooplankton communities were obtained by filtering the 30 l of water through three sieves with the mesh size of 71, 189, 526 micrometers. Main task of my study was to determine the species and size composition of the zooplankton communities in ponds with different substrates. In the first phase, ponds with natural (Erica sp.) and artificial (geotextile) material were monitored for the development of zooplankton communities, together with control ponds without any substrate. Due to negative experience, pikeperch production in the second phase was supported with the prey fish stocking rather than the geotextile substrate the larvae of common carp (Cyprinus carpio) and grass carp (Ctenopharyngodon idella). In the first phase of the experiment, the influence of the tested substrates (variants hereafter) on species diversity and abundance of the zooplankton communities was not statistically proven. Higher average values of zooplankton abundance were achieved in the variant with Erica sp. substrate (829 + - 572 ind.l -1 ), while the variant with geotextile substrate showed lower average value of abundance (658 + - 502 ind.l -1 ). It seems that the substrate from the natural material has a positive effect on the development of zooplankton communities in ponds. However, this positive effect was not confirmed in the second phase. Higher average values of zooplankton abundance were achieved in the variant with food fish (407 + - 154 ind.l -1 ) and lower abundance values in the variant with Erica sp. substrate (348 + - 215 ind.l -1 ). Any influence of the tested variants on the species diversity or the abundance of zooplankton communities was not statistically proven in the second phase.
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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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Effect of carp feeding on species composition and dynamics of zooplankton in ponds
ŠAUER, Pavel
Aim of this thesis was an analysis of the feeding influence on species composition and dynamics of zooplankton. The ponds were stocked with common carp (Cyprinus carpio).The theoretical part describes the planktonic communities, seasonal dynamics of zooplankton, pond management, food of carp and methodology. The practical part deals with, based on sampling, analysis of species composition and dynamics of zooplankton.
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Reaction of Soil Rotifers on Chemical Stress in Substrates of Spoil Heaps
BIZOS, Jiří
Abundance and species composition of soil rotifer communities was investigated in two seasons and six sites on dumps in the Sokolov mining area (Czech Republic). Every site was split into three plots, which differed in toxicity for vegetation and chemical composition of spoil material. The ability of soil rotifers to live in environment of spoil materials and the effect of pollution were studied in field conditions. According to results, abundance and species composition did not correspond to chemical environmental characteristics. Species composition of rotifer communities was affected by environmental variables such as vegetation, more likely than direct effect of chemical composition of spoil material.
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The role of rotifers by filtration of \kur{Cryptosporidium} in water column
BRŮČKOVÁ, Petra
Filtration abilities of Cryptosporidium parvum oocysts by rotifers (Brachionus calyciflorus) were studied. The filtration rate of rotifers is quick: the passage of oocysts through the digestive system is few minutes only. During the first 10 minutes 24300 of whole amount one million oocysts passed through the digestive system of 100 rotifers. Moreover, 93% of oocysts were death after passage. All oocysts expelled were unable to infect suckling BALB/c mice. Oocysts were degraded in mastax, stomach and intestine. Rotifers can be use for detection of cryptosporidia oocysts in water and they effectively decrease their numbers.
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