National Repository of Grey Literature 45 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Phylogeny and ecology of family Planorbidae
Běláčová, Kateřina ; Juřičková, Lucie (advisor) ; Lorencová, Erika (referee)
Phylogenetics is a sub-discipline of biology which focuses on classification of organisms based on their evolutionary development. Morphological and anatomical features have been traditionally used in reconstruction of phylogeny but with the onset of modern technology their role has been partly taken up by molecular analysis. Family Planorbidae is a very diverse group that includes species with very different morphology. This work aims to provide an overview of the phylogeny within Planorbidae family and discuss the importance of the individual features used in determination based on the results of the published studies.
The influence of morphological and microstructural characteristics to land snail degradation in forest environment
Říhová, Dagmar ; Juřičková, Lucie (advisor) ; Bogusch, Petr (referee) ; Čejka, Tomáš (referee)
The decomposition of land snail shell is a complex process involving a number of factors and influences, including the characteristics of conchs themselves. In particular, it is the shell size with which the progress and the rate of degradation are tightly bound. Post-mortem changes begin with the loss of the original colour and, in the case of transparent species, by the opacification of the shell wall. Subsequently, the periostracum disruption and dissolution of calcium layers occur. However, this sequence may be reversed for some small species (e.g. Columella aspera, Nesovitrea hammonis). Animals mechanically destroy empty shells, humic acids from the substrate cause their artificial dyeing. Fungal mycelium or colonies of Streptomyces grow on the surface of the conchs. The plant roots are also involved in shell decomposition. While degradation of large shells starts with periostracum disruption and subsequent ostracal dissolution, periostracum of small shells persists even after dissolution of ostracal layers. The phenomenon is caused by high resistance of the periostraca of small species. In the case of large shells, periostracum has primarily a "building" function during shell formation, and sometimes it is flaking off already during the snail's life. For small species, it is an important part...
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
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.

National Repository of Grey Literature : 45 records found   1 - 10nextend  jump to record:
See also: similar author names
3 Juričková, Lenka
3 Juřičková, L.
1 Juříčková, Ladislava
3 Juříčková, Lenka
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