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Holocene Succession of Mollusc Assemblages in the Southern Part of Kokořínsko Area
Oravec, Jan ; Juřičková, Lucie (advisor) ; Beran, Luboš (referee)
The sandstone rock cities of the Bohemian Cretaceous Basin are traditionally considered floristically and faunistically impoverished areas, because the environment of acidic quartz sandstones complicates the development of developed biocenoses. The unfavourable abiotic conditions are compensated for geomorphological diversity of the landscape, which creates a wide range of locations providing habitats for many biological species with different ecological requirements. However, the current appearance of the sandstone areas is due to the extensive transformation of the environment in the late Holocene, as evidenced by the rich subfossil communities of terrestrial gastropods. In the presented study, the succession of postglacial malacocenoses was processed from five sites in the southern part of the Kokořínsko area, demonstrating the continuous development of species-rich forest habitats during the early and middle Holocene. The presence of calcareous encrustations on the surface of acidic sandstone walls, which allowed the continuous occurrence of calciphilous mollusc species, is also documented from this wet period. The gradual transformation of the natural environment is related to the beginning of the late Holocene and was caused by the leaching of nutrients from the soil horizons and the...
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Relationship between recent and Holocene mollusc fauna diversity of the Veľká Fatra Mts.
Kubíková, Kateřina ; Juřičková, Lucie (advisor) ; Horáček, Ivan (referee)
Quaternary molluscs assemblages are one of the most important sources of information used for palaeoecology and biogeography reconstructions, yet little attention has been paid to the informative value of quaternary profiles on a landscape spatial scale. In the area of Velka Fatra Mts., a large number of existing records concerning both recent and quaternary land snails enable us to compare Holocene and recent species diversity to estimate how many profiles are needed to evaluate species richness of such geomorphologically diverse area. In this study, available data are supplemented with samples from additional recent sites and quantitative analysis of material from quaternary profiles Stankovany and Skamenelá skala. In recent sites, 129 species of terrestrial molluscs were recorded (more than 72 % of land snail species occurring in Slovakia). Samples from all seven Holocene profiles yielded 93 species, covering more than 85 % of recent land snails diversity. On the other hand, only about 50 % of recent land snail species were recorded in a single profile, thus highlighting the importance of multiple profiles evaluation in palaeoecological studies.
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Succession of mollusk assemblages in quarries of Bohemian Karst
Kocurková, Alena ; Juřičková, Lucie (advisor) ; Horsáková, Veronika (referee)
Molluscan succession was studied in 18 abandoned limestone quarries of different age in Bohemian Karst. The number of species in studied quarries increases in the time. The less species were found in the oldest quarries. This trend was probably caused by habitat diversity decline although it is not conclusive. The best predictors of mollusk species composition are type of surrounding vegetation, light and the cover of tree layer. It is important to take into account correlations of the other environmental variables with light and the cover of tree layer. Compositions of mollusk assemblages of north and south-facing slopes differ, but these differences diminish with ongoing succession. Quarries represent suitable model sites for the study of succession.
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Possibilities of land snail endodispersion via bird gut
Simonová, Jasna ; Juřičková, Lucie (advisor) ; Krištín, Anton (referee)
English abstract Passive dispersal is a fundamental mode of land snail dispersal as their ability of active dispersal is very limited. Birds are considered to be important vectors of snail dispersal for a long time. Snails can be dispersed both attached on a bird externally (ectozoochory) or being swallowed by bird and then expelled alive (endozoochory). The possibility of endoozoochory has been proved only for few species of land snails. The aim of this thesis was to test whether endozoochory is possible for more combinations of snail and bird species. Snails were offered to birds in laboratory conditions and to those kept in animal rescue stations. Then faeces and regurgitated food were collected and searched for snail shells. Viability of undamaged shells was examined. Out of 4519 snails of 15 species offered, 62 % were consumed by birds and 240 individuals (5.3 % of those offered) were found in faeces undamaged. The total of 27 individuals of four species (Clausiliidae: Alinda biplicata; Chondrinidae: Chondrina avenacea; Vertiginidae: Vertigo antivertigo, V. pygmaea) were found alive. Some birds also regurgitated consumed snails. The total of 121 individuals (2.7 % of consumed) of four species were regurgitated undamaged. The number of 35 snails of all four regurgitated species (Chondrinidae: Chondrina...
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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.
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Flatworms (Platyhelmintes: Tricladida) in the Czech Republik
Reslová, Marie ; Juřičková, Lucie (advisor) ; Buchar, Jan (referee)
This work focuses on the freshwater triclads and summarizes information about species occurring in the Czech Republic. Particular chapters concerned generally with taxonomy, anatomy and ecology of triclads; morphology, ecology and occurrence of each species is discussed in detail. 17 triclad species were recorded in the Czech Republic before now, some of them are considered as endemics. The majority of common triclads is determinable according to the head shape, but determination of Dugesia lugubris, D. polychroa a Polycelis nigra, P. tenuis is possible only based on the penis morphology. Some species can be regard as bioindicators, because of their narrow ecological requirements: cold water with high content of O2 - Dugesia gonocephala, Crenobia alpina, Polycelis felina; higher concentration of Ca2+ - D. gonocephala, Phagocata vitta, Planaria torva; oligotrophic standing waters - Polycelis nigra; eutrophic standing waters - Dugesia polychroa, Polycelis tenuis. Species of underground waters and springs are interesting and still unexplored ecological group of triclads.
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Dispersion of freshwater gastropods
Buďová, Jana ; Černý, Martin (advisor) ; Juřičková, Lucie (referee)
Freshwater gastropods (Mollusca: Gastropoda) belong to two tradional taxonomic groups: prosobranchs (Prosobranchia) and pulmonates (Pulmonata). Most of these molluscs are characterized by low vagility. Therefore they usually rely on passive dispersal. Their dispersal vectors are mostly birds and water. Animals can transport snails both externally and internally. Direct methods (capture.mark.recapture, radio - tracking) and genetic methods could be used to study dispersal. For genetic studies can be used many type of molecular markers, but the recently most popular are microsatellites. According to recent studies, the dispersal of freshwater gastropods is probably not as frequent and wide - spread as assumed before. Key words: freshwater snails, dispersal, dispersal vectors, capture - mark - recapture, molecular markers, population genetics
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Land snail shell degradation in forest environment
Říhová, Dagmar ; Juřičková, Lucie (advisor) ; Horsák, Michal (referee)
Experimental shell degradation of nine common Central European pulmonate snail species in forest ecosystems in the Czech Republic was investigated. Model shells were deposited for 6, 12, 24 and 36 months in leaf litter of six different places; than removed, dried and photographed. Set of alternations was analysed by CANOCO 4.5 statistical system. Small species degrade different from large ones. Large species corrode outwards, after periostracum disruption the ostracum dissolves and holes appear. Small species corrode out from within, calcium carbonate dissolves and small windows arise. The shell degradation proceeds with different rate on various localities. Some localities have characteristic types of alteration, e.g. peat bog pine forest exhibits ostracum dissolution and periostracum deformation. The ultimate influence of the degradation is caused by pH value and humidity. Shell shape and size have effect on its degradation. Moreover, other important decomposition agents are living animals. Powered by TCPDF (www.tcpdf.org)
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