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Molluscs as a new model system in molecular biology
Ber, Tobiáš ; Svoboda, Petr (advisor) ; Pergner, Jiří (referee)
Molluscs form the second largest animal phylum and are of great biological and economic significance. Their distinct evolutionary adaptations enabled them to inhabit a broad range of environments, with many of them invading new areas and becoming invasive pest species. Despite their importance, molluscan model systems have not received attention they deserve. In this bachelor thesis, I have reviewed the current state of molluscan model systems in molecular biology and analyzed their significance for more common use. From available data, it is apparent that the already established molluscan models are either marine or fresh-water, and therefore require more complex logistics and maintenance in order to set up a laboratory culture. To remedy the problem of aquaculture, the use of terrestrial gastropods was proposed. Here, I suggest that gastropods genus Deroceras have a good potential to become a new prominent molluscan model system in molecular biology.
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Diversity of methods used for characterization of molluscan hemocytes
Jindrová, Zuzana ; Horák, Petr (advisor) ; Skála, Vladimír (referee)
Hemocytes are the main immune cells of invertebrates; therefore they can be found in molluscs, too. They differ both in morphology and function. The two generally accep- ted morphological types, granulocytes and hyalinocytes, vary in the level of phagocy- tosis and encapsulation, production of reactive oxygen species and nitrogen oxide, and presence of some enzymes. There is an array of methods by means of which hemocy- tes can be characterized. Microscopy serves particularly for study of morphology. An- tigens localized on the surface can be determined by monoclonal antibodies or lectin probes. Hemocytes can be divided on the basis of cell size and granularity using gra- dient centrifugation or flow cytometry. Production of nitrogen oxide and reactive oxy- gen species is monitored by adding appropriate substrate which changes its proper- ties after reaction with the radical. It may become fluorescent, change absorbance of the solution or form a visible precipitate. Another possibility is the use of chemilu- miniscence. The objective of hemocyte research is to explain mollusc-pathogen inter- action. 1
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Comparison of Natural and Human-influenced Malacocenoses of the Krasíkov Village
Šiřinová, Veronika ; Říhová, Dagmar (advisor) ; Podroužková, Štěpánka (referee)
The aim of this diploma thesis is to compare natural and human-influenced malacocenoses in the vicinity of the villages Krasíkov and Domaslav in the district of Tachov, Czech Republic. Inventory research was conducted between 2012 and 2013. A total of 36 gastropod species were found, and a total of 1088 snail shells were collected. On some of the surveyed sites (the farm Krasíkov, Domaslav, the pond near Ovčí vrch) the influence of anthropic stress is evident. Four species found during this study are also listed in the Red List of Threatened Species of the Czech Republic (Aegopinella nitidula, Balea perversa, Ena montana, Vertigo pusilla). Based on the results of the research, two variants of the didactic use of a such malacological research were created in the teaching of natural science and biology. Keywords: Mollusca, Gastropoda, malacocenosis, species diversity, ecology of mollusk assemblages, Krasíkov.
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The influence of geology to the diversity of molluscan assemblages
Krajinčáková, Lucie Linda ; Juřičková, Lucie (advisor) ; Myšák, Jan (referee)
Molluscan populations are influenced by various factors of environment where they occur. In my work I am taking particular atention of soil properties, which are directly influenced by the geological substrate, and of course other factors which are with soil properties either directly or indirectly related. The important benchmarks are especially moisture, pH, calcium content and vegetation cover. This bachelor thesis also deals with utilization of calcium salts. Geological substrate is closely linked with the diversity and abundance of molluscan populations. Various pedochemical factors affect molluscan communities whether it is the amount of calcium in the soil or a pH value. In the past different authors found different dependencies between environmental factors, species composition and diversity of molluscan communities. Most of the studies were focused on very specific habitats and locations. In this thesis I tried to organize our knowledge about the specific effects of various environmental factors, especialy compositíon of geological substrate on malakofauna. Key words: Mollusca, Gastropoda, Geological substrate, diversity
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On the Nothernmost and Southernmost Limits of European Land Snail Spatial Ranges
Křepelová, Lucie ; Juřičková, Lucie (advisor) ; Horsák, Michal (referee)
The aim of this work was to evaluate the limits of ranges of European land snail species along the north-south gradient. To work out the document it was necessary to prepare the set of digitalized maps, that enabled to create the database of ranges of the individual land snails species. Based on obtained data I tried to identify places where the northern and southern borders of species ranges are the most frequent. The landsnails' ranges are affected not only by particular life requirements of the individual species (potential limits), but also by other conditions, especially climatic, geographical and historical (truncated limits). In this work I focused on their differentiation. Above mentioned process also enabled me to track the north- south changes in species richness of the landsnails taking into consideration the truncated and potential limits. The most important natural barriers constraining that numerous of species cannot naturally widespread from the south to the north are the Scandinavian Mountains, the Alpes and the Carpathians and suprisingly also southern borders of german and polish lowlands. On the other hand, spreading of the species form the north to the south is limited only by the Alpes. I also tried to distinguish the group of species whose ranges are not influenced by these...
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Phylogenetic and ecological impact to the microstructures of mollusc shells
Nedvědová, Jana ; Juřičková, Lucie (advisor) ; Simon, Ondřej (referee)
This bachelor thesis summarizes the available information on microstructures of mollusc shells. The aim was to provide an overview of the different types of microstructures for specific specimens from different environments, as well as to obtain as much information as possible about the ecology of these animals. The first part summarizes the basic information on the shell formation. The following chapter summarizes known microstructure types of mollusc shells. Microstructures of molluscs living in terrestric, freshwater and marine environment are discussed. The influence of temperature changes on the shell microstructure of V. viviparus, the occurrence of vaterit within C. fluminea shells, the extreme environment of hydrothermal vents and cold seeps, as well as extreme temperatures on rocky shores, have been mentioned in more detail. The microstructures of related molluscs are compared with regard to ecology to determine whether the occurrence of microstructures in a particular group is given by the phylogeny of these animals, or if the changes in microstructures can be affected by different ecology. Key words: microstructures, molluscs shells, impact of phylogeny, impact of ecology, calcium carbonate, Mollusca, gastropods, bivalves
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Quaternary molluscs of Blanský les
Menšík, Jakub ; Juřičková, Lucie (advisor) ; Pokorný, Petr (referee)
Rich mollusc assemblages preserved in two profiles of fossiliferous sediment in the Blanský les area, provided the evidence about the Late Glacial and Holocene in this region, which is one of the most faunistically known areas of Central Europe. Findings of Quaternary faunas are very rare in Southern Bohemia, so these two soil profiles near Český Krumlov are so important for understanding the postglacial succession of Central Europe. The fossil mollusc assemblages showed an early appearance of forest species, which dominated both sites from the Boreal till Subboreal. Forest development in the Holocene Climatic Optimum reached a maximum, due to the absence of Neolithic man. Steppe species almost completely disappeared during this period. The development of the Young Holocene was linked to a decrease of the forest on the first site and the deforestation of the second site, due to a combination of a humidity decrease and human impact. In addition, some southern elements involved in the postglacial colonization of Central Europe, were found there. A few of them were found in a much older deposit than expected.
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Mollusca of European cities
Wolfová, Lucie ; Juřičková, Lucie (advisor) ; Drvotová, Magda (referee)
This bachelor thesis summarises knowledge of urban mollusc fauna. It shows cities as the centres of mollusc diversity in agricultural landscape but also as areas where high level of homogenization of mollusc assemblages were evidenced, therefore replacing native species, often endemics, with non-native and invasive species. Homogenization of urban mollusc fauna is especially caused by passive dispersal of species by human as well as to urban climate that is more favourable for spreading and surviving of non-native species, usually from warmer areas, than surrounding. There is mentioned another connected topic in this thesis - types of mollusc spreading. Furthermore, there is summarized which species of mollusc are typical for urban environment, what are the factors influencing the mollusc fauna and last but not least the methodological approaches for study of urban mollusc fauna.
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Holocene succession of European mollusc fauna
Menšík, Jakub ; Juřičková, Lucie (advisor) ; Moutelíková, Jitka (referee)
Abstact Study of Quaternary mollusc succession has a long-term tradition in Europe. It is because mollusc shells used to be commonly and numerously preserved in calcareous quaternary sediments of various origins. Since the second half of the last century, these successions are used as proxy data in paleoecological studies. Based on knowledge of recent ecology and composition of Quaternary assemblages, mollusc species can be divided into ten ecologicalgroups used for a reconstruction of paleoenvironment. The ecological group of strictly forest species is crucial for central European fauna. . This group indicates the canopy forest with its characteristic microclimatic conditions, which represents zonal ecosystem of Central Europe. Indication value of molluscs for canopy forest habitats used to be in question in other parts of Europe except of Central Europe. That is why this theses reviewed available information on mollusc successions of strictly forest species across Europe based on a maps of known strictly forest species occurrences during the Late Glacial and Holocene. This visualization indicates the general movement patterns of strictly forest mollusc fauna from the Late Glacial to present. The main methodical problems in the study of Holocene mollusc succession are also commented.
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