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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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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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The crayfish plague pathogen Aphanomyces astaci in its introduced ranges: vectors, introduction pathways, genetic variation and host-pathogen interactions
Mrugała, Agata ; Petrusek, Adam (advisor) ; Füreder, Leopold (referee) ; Vralstad, Trude (referee)
- ABSTRACT - The crayfish plague pathogen, Aphanomyces astaci, is responsible for substantial declines and local extinctions of native European crayfish populations. As a consequence, the pathogen is now listed among 100 world's worst invasive alien species. The spread of A. astaci is greatly facilitated by its natural hosts, North American crayfish, that thanks to a long co-evolutionary history with the crayfish plague pathogen evolved efficient defence mechanisms. In contrast, European, Australian and Asian crayfish species are highly susceptible to this disease agent. However, progress of A. astaci infection in native European crayfish was observed to differ between distinct pathogen strains, indicating variability in their virulence. Indeed, we demonstrated a relationship between patterns in crayfish immune response and A. astaci virulence in an experimental infection involving the European noble crayfish and three differently virulent crayfish plague strains. The European continent is currently inhabited by at least eight North American crayfish species. The carrier status was confirmed in six of them, including also Orconectes cf. virilis occurring in the Netherlands and the UK. In this country, we detected Aphanomyces astaci presence in some populations of the non-indigenous crayfish species as well...
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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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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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Microparasites and fecundity of Daphnia at environmental gradients of canyon-shaped reservoirs
Hubová, Jana ; Petrusek, Adam (advisor) ; Macháček, Jiří (referee)
The original aim of my diploma thesis was examination of fixed samples of cladocerans from the Daphnia longispina species complex from reservoirs Vír and Vranov for the presence of 4 groups of microparasites: microsporidia, oomycetes, the protozoan Caullerya mesnili, and the yeast Metschnikowia bicuspidata. The next aim was to determine the effect of parasites on Daphnia fecundity, and determination of their spatial and temporal distribution within reservoirs. From the total number 4452 of examined Daphnia females, however, only 56 individuals were infected. This number was not sufficient for the planned analyses. As I recorded for all examined individuals the clutch size, I thus dealt to a large extent with an alternative issue: the temporal and spatial variation of, and the influence of environmental factors on Daphnia fecundity. Both studied reservoirs are characteristic by canyon-shaped profile that allows formation of environmental gradients on the horizontal as well as vertical axis. The results confirm that reservoir identity, season, and location within the reservoir (or gradient of food supply) have all significant effects on fecundity. During my work I have encountered difficulties associated with determining microparazites from fixed zooplankton samples. The appendix section of my thesis...
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Factors influencing movement and behaviour of animals in riverine environment
Horká, Petra ; Petrusek, Adam (advisor) ; Matěna, Josef (referee) ; Kováč, Vladimír (referee)
Animals living in riverine environments are influenced by various abiotic and biotic factors which shape their behaviour. Among the most distinctive behavioural traits by which animals react and adapt to environmental variability is movement behaviour. In my study I focused on movement and distribution of several species and their response to environmental and anthropogenic factors. The thesis consists of two parts: the first part synthesizes studies on behaviour of European grayling Thymallus thymallus, ide Leuciscus idus and an invasive crustacean Hemimysis anomala; the objectives of individual projects were to determine which environmental factors influence the species' behaviour and how. The first two chapters present extensive radio-telemetry studies which examined diel movements and migration of ide (one year observation in the River Elbe) and European grayling (study conducted in autumn-winter periods of three consecutive years in the River Blanice, focusing on differences between juveniles of wild and hatchery origin). The third study was also conducted in the Elbe and evaluated the diurnal behavioural patterns and spread of the Pontocaspian mysid shrimp Hemimysis anomala. The second part of the thesis consists of two chapters focusing on young-of-the-year (YOY) fish assemblages: the first...
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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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