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Passive dispersal of land snails (Gastropoda: Pulmonata) with focus on endodispersion via birds
Simonová, Jasna ; Juřičková, Lucie (advisor) ; Pech, Pavel (referee)
The ability of land snail active dispersal is very limited. Despite that, they have colonized even very isolated habitats and some species are able to disperse relatively fast on continental scale. This used to be explained by passive dispersal, especially via birds. Land snails could be transported on bird's body (ectodispersion) as well as inside their digestive tract (endodispersion), but the direct evidence of these processes has been more likely anecdotal. A review concerning passive dispersal of land snails via birds with focus on endodispersion is presented in this bachelor thesis. The methodological aspects of experimental studies, including relevant insights of other organism's endodispersion studies, are discussed. Selected traits of land snails and their avian vectors which can affect success of endodispersion are also discussed.
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Floodplain mollusc fauna of the lower Elbe and its tributaries -its history, ecology and changes induced by invasion plant species
Horáčková, Jitka ; Juřičková, Lucie (advisor) ; Pokorný, Petr (referee) ; Čejka, Tomáš (referee)
The molluscs are very suitable model of invertebrate group for ecological and palaeoecological studies for their specific traits. In the first part of the thesis, we showed based on available fossil mollusc successions that development of the floodplain mollusc fauna took place quite different way in various river floodplains, depending on their specifics and geographical location, because especially the ones situated in the chernozem area of the Czech Republic had very different history. Detailed processing of five fossil mollusc successions in the lower Ohře River floodplain confirmed the impoverishment of recent forest malacofauna does not relate to natural processes only (chapters 3 and 10), but it arises from historical development of this area which was under permanent stress of the human settlement and agricultural utilization (chapter 1) since the coming of the Neolithic people. We made similar conclusions in case of another 11 fossil mollusc successions in the neighbouring České Středohoří Mts. (chapter 2). In the second part of the thesis (chapter 3), we investigated the ecological patterns responsible for species richness and composition of the floodplain mollusc fauna are especially the elevation and humidity gradient, and then vegetation type and its biomass, light conditions of the...
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Importance of flood drifts of the Ohře River for the study of alluvial mollusc communities
Ratajová, Michaela ; Juřičková, Lucie (advisor) ; Čejka, Tomáš (referee)
When water levels are increased, for instance in case of spring thaw and summer floods, various materials including terrestrial gastropods are pulled down from shores by water. This accumulated material is called flood drift and when interpreted accurately, its composition can provide useful information not only from faunistic point of view. In the past, flood drifts were used to supplement faunistic research of various areas, since it helps to reveal species which are difficult to detect using regular methods. This is also the case of the river Ohře. For the dynamics of molluscan association, water is a significant corridor connecting very similar places. I have attempted to verify, whether it is transported via a river bed, i.e. via stream corridor by means of flood drifts. The results of this theses confirm that gastropods are able to survive in the watercourse and cling several hundred metres down the stream. Thus we talk about short distance spreading. This transport is used by various terrestrial gastropods; however, bigger gastropods are much more likely to survive.
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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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Relations among soil characters, vegetation, and mollusc communities of montain beech forests
Kopalová, Zuzana ; Juřičková, Lucie (advisor) ; Pech, Pavel (referee)
In three different sites of the Jizerské hory Mountains, we have analysed the effect of soil composition on snail assemblage patterns at small spatial scale. We have chosen such sampling sites so that one site was potentially rich in species, thus, we chose a beech forest enriched with presence of maple (Acer pseudoplatanus), perennial honesty (Lunaria revidida) and white butterbur (Petasites albus), and the second site was bare acidophilous beech forest (Fagetum nudum). In total, there was sampled 22 species of land snails with 919 individuals. None of the soil characteristics has been found to have any statistically significant effect on the snail abundance in sampled sites. For better illustration of species and ecological diversity in the discussed sites, we have used Ellenberg's indicator values for light, humidity, soil reaction, temperature and nutrients. The higher number of species at the enriched sites has been confirmed just for one site out of three. In the Jizerské hory Mountains and surroundings, i.e. at a larger landscape scale, there has been observed an effect of geomorphology, vegetation, human impact and slope orientation on the species diversity. At sites with calcareous background, there has been observed an increase in the species diversity. Sites with rich herbal cover and...
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Palaeoecological aspects of Rhynchostreon Bayle oyster evolution
Rantuch, Jakub ; Košťák, Martin (advisor) ; Juřičková, Lucie (referee)
This paper presents a multilevel analysis of palaeoecological aspects of the process of the Rhynchostreon genera evolution. According to the latest results of research, the process of genus appears to be more dynamic than previously assumed.The processes of internal dynamics of the environment in conjuncture with other studied aspects of the late cretaceous environment (e.g. paleotemperature, salinity, etc.) were a significant factor that initiated the activity of selective pressure and represents an important factor in group evolution. In this work we provide the overall hypothesis about co-evolution of two intrageneric (sisters) lineages in Rhynchostreon genera. The definiton of evolutionary trends of intrageneric lineages within the presented hypothesis (including a new description of oyster species) is supported by various analytical methods, which anchors them in the current zoological nomenclature system. An electron microscopy, isotopes and biometrical analysis of a shell in cooperation with some of the sedimentologic methods suggest a relation of lithology (as a result of environmental aspect) and evolution process. The transregional concept of proposed ecological-evolutionary models, based on materials studies from various paleogeographic regions of cretaceous world, increases the...
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Influence of environment on morphological and stuctural characteristics of European snails
Holubová, Anna ; Juřičková, Lucie (advisor) ; Horsáková, Veronika (referee)
In this thesis, I explored the relationships among morphological characteristics of European land snail's' shells, their environment and life strategies. I assembled a database of morphological traits, characteristics of the environment and life strategies of land snails from literary sources. This file was merged with unique dataset from field sampling along a latitudinal gradient through Europe and the morphological characteristics of each species were averaged on real populations from particular sites. This package was analyzed by multivariate linear regression (GLM). In this work I demonstrate that the color pattern is affected by latitude and occurs mainly in gastropods with wider shell. Wide shell also appears mainly in snails with a smooth shell surface and shallower suture. Snails at lower altitudes mostly have calcified shell lips. A snail species with teeth in the mouth of shell, with ribs on the shell surface, and larger relative height of the shell, live in areas with higher calcium content in the leaf litter. Deep sutures on the shell are more frequent in shells from sites with higher rainfall seasonality. Especially in areas with higher rainfall seasonality we can find less gastropods with periostracal structures on the shell, however, their occurrence increase in areas with canopy...
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Shape, surface and microstructural characteristics of landsnail shells and theirs function.
Holubová, Anna ; Juřičková, Lucie (advisor) ; Bogusch, Petr (referee)
Snails are popular group of invertebrates which intrigues people with their shell. Land snail shells take a variety of shapes and colors, their surface is covered by various surface structures. Shape of the shell is often afected by the environment in which snails live. Elongated shells are found on snails crawling along vertical surfaces, however snails with flattened shells crawl primarily on a horizontal surface. Keeled snails often hide in cracks in the rocks and under stones. Just as the shape is affected by the environment, so can the environment affect the surface structure and microstructure of the shell. We can find a snail with a shell that is covered with hairs in a humid environment and snails with thick periostracal layer in acidic one. The findings summarized in this thesis can be helpful to paleontological reconstructions of the environment, and in morphological identification of recent species by their shells.
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Genetic and Morphological Variability of the European Genus Cochlodina (Mollusca: Gastropoda: Clausiliidae) with Focus on Species C. laminata (Montagu, 1803)
Szalontayová, Veronika ; Juřičková, Lucie (advisor) ; Drozd, Anna (referee)
This thesis focuses on the genetical and morphological diversity of plaited door snail (Cochlodina laminata). While small distribution ranges are typical for most species belonging to genus Cochlodina, the distribution range of C. laminata covers most of the European continent, except for its coolest and warmest parts. It has been previously suggested that this species might in fact be a complex of several species and large genetical as well as morphological diversity has been mentioned - however, yet undescribed - in previous studies. Sequences of two mitochondrial genes were used (16S rDNA, COI) and thirteen morphological characteritics have been assessed to investigate this diversity. I discovered that the current concept of C. laminata as a species is not in accordance with the discovered genetical nor morphological variability. The original species C. laminata/C. dubiosa form a common species complex and also interpretation of C. fimbriata will need to be assessed in more detail in the future. Other Central European species are valid species.
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