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Changes in spatial distribution of gelatinous zooplankton: causes and consequences
Krylová, Pavla ; Petrusek, Adam (advisor) ; Rulík, Martin (referee)
During the day, changes in the spatial distributions of organisms in the water column occur repeatedly, especially in diurnal vertical migrations, which affect abiotic and biotic components of ecosystems. The migratory behaviour occurs worldwide in the oceans and in fresh water, in different habitats and under different physical conditions. The main migrants are gelatinous zooplankton, which are a heterogeneous group of invertebrate animals, although phytoplankton, nekton and other representatives of zooplankton also migrate. The main focus of the study of diurnal vertical migrations is proximate and ultimate factors that influence the migration. Furthermore, occurrence and density of organisms are examined. To study vertical migrations of gelatinous zooplankton, it is the easiest to study jellyfish because of their size. The distribution behaviour might also be observed in freshwater zooplankton. Two university studies of diurnal vertical migration of freshwater jellyfish were executed in previous years. This work aims to: summarise the current knowledge about spatial distribution - especially of diurnal vertical migration, describe in detail proximate and ultimate factors and compare them between freshwater jellyfish, gelatinous zooplankton and jellyfish. Key words: gelatinous zooplankton,...
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Diversity of freshwater epigean amphipods
Rutová, Tereza ; Petrusek, Adam (advisor) ; Sacherová, Veronika (referee)
Gammarids, the most diverse group of Amphipoda are present in marine, brackish and fresh waters. In freshwater there are forms inhabiting the surface (epigean) and underground (hypogean) habitats and this thesis will be focused on epigean freshwater groups. Freshwater gammarids inhabit the continental waters of all continents, but the highest species diversity is evident in the Palearctic region. However they cannot be found in the surface waters of the tropical regions. These amphipods are characterized by the absence of any resistant or larval stages. Thus the present diversity and distribution reflects historical events like the fluctuation in sea levels, orogeny or period of glaciation from the Paleocene to the present. The goal of this thesis will be to summarize which processes and in which period the diversity of freshwater epigean amphipods were affected. One part of this thesis is dedicated to the families occurring in Australia (Chiltonidae), New Zealand (eg. Phreathogammaridae) and the North and the South America (Hyalellidae). The main focus is on family Gammaridae in which according to recent studies should include lineages occurring in the entire Palearctis including endemic groups in the Lake Baikal and across the Ponto-Caspian area. In the history of the development of gammarids...
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Seasonal variation of activity and pathogen prevalence in populations of the spiny-cheek crayfish
Matasová, Klára ; Petrusek, Adam (advisor) ; Slavík, Ondřej (referee)
The most widespread of invasive crayfish in the Czech Republic is the spiny-cheek crayfish (Orconectes limosus). It is a major disease carrier of crayfish plague, caused by the pathogen Aphanomyces astaci. The infection is lethal to European native species of crayfish. Transmission of this disease is usually associated with the spread of crayfish, which is dependent on their movement. The main aim of this work was to evaluate the differences in crayfish migratory activity in the Pšovka brook among seasons, and assess the factors that may affect it, by the use of radiotelemetry and trapping. We tested the hypothesis that crayfish use brook in the period from spring to autumn and then return back into a pond to overwinter. Furthermore, we evaluated how far from the pond crayfish migrate, and whether there is any relationship between migration and the season or water temperature. The results demonstrate that the activity varies among seasons (being strongly affected by breeding season) but in most studied periods did not significantly depend on water temperature. According to our monitoring, the spiny-cheek crayfish does not spread substantially to upstream parts of the Pšovka. Seasonal migration between the pond and the brook was monitored using two-way flow-through traps installed at the mouth of...
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Interactions between microsporidial parasites and the host cladoceran Daphnia pulex in a simple environment of a forest pond
Krylová, Pavla ; Petrusek, Adam (advisor) ; Hyliš, Miroslav (referee)
Among the most common endoparasites who infected small crustacean Daphnia pulex include microsporidia. These intracellular parasites appear to look like a simple single- celled organisms, but their cell structure and lifecycle prove the opposite. Microsporidia are species-specific. Although they infected most organisms of the animal kingdom, they are not yet sufficiently understood. This theses is inderectly followed up to the studies of waterflea Daphnia longispina and microsporidia Berwaldia schaefernai from the dam reservoirs The aim was to analyze closer microsporidian infection on host Daphnia pulex in a forest pool with simple enviroment, which included monitoring time dynamics of Daphnia population and identification infection caused by microsporidia Berwaldia singularis and yet unknown microsporidia labor-marked "HVH". Laboratory work included determination of zooplankton and parasites, calculation of prevalence, laboratory experiments with transmission of microsporidian infection between healthy and infected flea culture or by isolated spores. Genetic analysis of aquatic invertebrates from the forest pool, especially larvae of mite and mosquitos, helped make closer microsporidian life cycle and hypothesis about secondary hosts, for the presence of pathogen DNA using specific DNA...
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Freshwater fishless pools: from the metacommunties to the systematics
Juračka, Petr Jan ; Petrusek, Adam (advisor) ; Kotov, Alexey (referee) ; Zhai, Marie (referee)
Freshwater fishless pools: from the metacommunities to the systematics Petr Jan Juračka, Ph.D. Thesis, 2016-04-08 ABSTRACT Despite their small size, freshwater fishless pools often contain complex communities and substantially increase regional invertebrate and macrophyte biodiversity. The main core of this thesis originates from such habitats, which were newly created for the conservation purposes in the Protected Landscape Area Kokořínsko, Czech Republic. This landscape consists of deep valleys separated by steep sandstone ridges and is characteristic for very sparse stream network and low number of large water habitats, which consequents in generally low abundance of waterfowl. We studied microcrustacean metacommunities of 42 selected pools scattered over the area of approximately 220 km2 . Using variation partitioning of the species composition, analyses of the species richness and colonization experiment in the study area, we identified that spatial distribution of the habitats and number of neighbouring aquatic habitats play a major role in assembly of local communities. This led us to the conclusion that the landscape heterogeneity served as a partial barrier to dispersal of microcrustaceans. Subsequently, we compared this pattern of the microcrustacean metacommunity with other invertebrates of...
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Macroecological analysis of economy
Krupička, Jan ; Storch, David (advisor) ; Petrusek, Adam (referee) ; Kratochvíl, Lukáš (referee)
Abstract: Brown et al. (2011) proposed a fundamental similarity between organisms and the economies of nationstates based on the distribution networks necessary for the functioning of the metabolism / economics and limitations arising from them according to the Metabolic theory of ecology. This work is primarily intended to investigate whether these limitations figure even within individual sectors of the economy and their relation to some other macroeconomic and demographic indicators. Key words: ecology, macroecology, metabolic theory of ecology, economy, energy
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Genetic diversity of stone crayfish Austropotamobius torrentium in marginal areas of its distribution
Pešek, Pavel ; Petrusek, Adam (advisor) ; Kouba, Antonín (referee)
Central Europe north of the Alps was colonized by one of the Balkan haplotype lineage of stone crayfish Austropotamobius torrentium after the end of the last ice age. Stone crayfish is considered a native species in the basins of the Danube and the Rhine. The origin of populations from the Elbe basin is still debated. Most of recent European studies dealing with the crayfish distribution indicate the stone crayfish in Elbe basin as non-indigenous species. The main aim of my work was to evaluate the question of the origin of stone crayfish in the Elbe catchment by describing the distribution of genetic variability, which has not been yet studied in the Elbe river basin for this species. I have used 617 base pairs long section of mitochondrial gene for small subunit I of cytochrome c oxidase (COI). The variability of this marker is reduced in area on the north of Alps, which agrees with assumption of rapid colonization after the end of last ice age. Observed haplotype diversity is nevertheless sufficient to suggest the most likely scenario. Among 22 populations from Elbe basin, one dominant and three rare haplotypes were found. Individuals from the isolated Luční creek close to the Krkonoše (Giant Mountains) region have a haplotype that has so far been found only in central Slovenia, and this population has...
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Detailed taxonomic and clonal structure of the Daphnia longispina species complex on the longitudinal gradient of the Želivka Reservoir
Stodola, Jakub ; Petrusek, Adam (advisor) ; Vaníčková, Ivana (referee)
Canyon shaped reservoirs are characteristic by specific environmental horizontal gradients, so they enable existence of several species of the Daphnia longispina complex in one water body. Due to preference of distinct environmental conditions Daphnia species occurre in the different localities. The aim of my thesis was to analyze detail taxonomical and clonal structure of Daphnia longispina group by ten microsatellite markers on longitudinal gradient and compare it between two consecutive seasons. Simultaneously I received newly discovered divergent mitochondrial lineage from Želivka reservoir. It was confirmed, that the distribution of species and their hybrids in water reservoir was non-concidental and the taxonomic spatial distribution is in two consecutive seasons relatively constant. On the contrary the spatial and temporal distribution of clones was very heterogeneous. Clonal diversity in the interspecific hybrids was lower than in the coexisting parental species. This finding supports the hypothesis, that there exist reproductive barriers between parental genomes. Most of the clones were substantively variable, but several clones that occurred in both seasons in similar localities were found. It is possible that some clones are able of overwintering in hypolimnion and in the spring...
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