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Phylogeny of the genus Helix (Mollusca: Gastropoda: Helicidae)
Korábek, Ondřej ; Juřičková, Lucie (advisor) ; Horáček, Ivan (referee)
The land snail genus Helix comprises large gastropods distributed in from France to Iran and in North Africa. Some of them have close linkage to humans - are synanthropic or are collected and consumed. The genus is most diverse in eastern Mediterranean. Taxonomy of the genus is now being revised from morphological point of view, and a molecular study is needed as a counterpart to that study. Here I present first phylogenetic data for the genus Helix, including almost all currently recognised species. I have used samples from various sources including dried bodies and tissue remnants. I have sequenced two commonly used mitochondrial markers (16S, COI). Position of the genus within Helicidae cannot be inferred from the dataset. The genus should be delimited in a strict sense, excluding genera Maltzanella, Cantareus, Cryptomphalus and Lindholmia. Division into subgenera, as proposed by various authors until now, is not supported with the exception of a split between subgenera Pelasga and the nominotypical Helix. Relationships between species and their groups are poorly resolved. Regarding species limits, the data are largely in agreement with new opinions based on morphology. There might be surprisingly high variability in shell characters within a species, as few morphologically characteristic taxa seem to be...
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The role of stream-corridors for the speading of invertebrates in the landscape
Ratajová, Michaela ; Juřičková, Lucie (advisor) ; Čejka, Tomáš (referee)
The characteristic environment along riverbeds forms corridors, which can be used by numerous organisms for their dispersion - stream corridors. Water is a useful medium of transportation, especially for the species with low dispersion abilities, such as annelids, molluscs and several arthropods. The terrestrial animals nearby the water flows are often adapted to the survival in the water. They are able to survive short term inundation, or reproduce very quickly to renew their abundances. However, well documented cases of the species spreading along the rivers are rather rare. Most of them are molluscs species. The banks of the Vltava, Berounka or Sázava rivers are colonized by the snail Arianta arbustorum. There is evidence of the spreading of annelids along some European rivers. Such examples, together with the various adaptations to survival of inundation suggest that the stream corridors really work as a spreading device.
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Diversity of the molluscs of Central Europaean Mountains
Kopalová, Zuzana ; Juřičková, Lucie (advisor) ; Dvořáková, Jana (referee)
This thesis summarizes environmental factors which influence both species richness and abundance of mollusc fauna, and it also describes molluscs' diverzity of the Czech Republic mountain areas. The abundance and species richness of mollusc assemblages are influenced mostly by accessibility of Ca together with correlated pH of soil, humidity, woodland structure together with character of litter, decomposed wood amount, and altitude. Results of number studies on these topics do not correspond to each other. The species diverzity of twelve mountain areas in the Czech Republic were described and 182 species (about 74 % molluscs fauna in the Czech Republic) were recorded. While east-west gradient is apparent for Carpathian species spreading, Alpine species are spreading to the north randomly. Western mountains contain higher proportion of species with wide zoogeographical range.
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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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Food preferences of land snails in a river flood-plain invoved with invasive plants
Ševčíková, Štěpánka ; Juřičková, Lucie (advisor) ; Čejka, Tomáš (referee)
Food preferences to five most widespread invasive plant species from river floodplains: Impatiens glandulifera, Helianthus tuberosus, Fallopia japonica, F. sachalinensis a F.x bohemica and one native species - U. dioica were studied on two common land snail species. Using three different methods I tried to recognize, whether or not these plants serve as a food source to Succinea putris and Urticicola umbrosus. From histological sectionsit was impossible to identify the plants. The majority of plants don`t provide structures usable for identification of plant in the snail maces. I was able to identify only H. tuberosus and U. dioica undoubtedly, thanks to trichomes. According to the results of laboratory tests, the most important factors for snails food preferences are plant species and the condition of plant material. U. umbrosus consumed much less fresh material than S. putris. Consumption of frozen leaves became larger for both species. The most preffered plant species were U. dioica and H. tuberosus. Only frozen I. glandulifera was consumed. Fallopia spp. were rejected both, fresh or frozen.
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Diversity of molluscan assemblages of temperate forests: model case of Křivoklátsko
Sobotová, Eliška ; Juřičková, Lucie (advisor) ; Dvořáková, Jana (referee)
1 Abstract: My bachelor thesis summarizes the impact of environmental factors and microhabitats on temperate forest snail assemblages: mainly on their diversity and abundance. Most authors consider humidity, calcium content and forest condition the main factors, which influence forest gastropod assemblages. However, othes have a different view on the importance of another factors such as composition of the forest vegetation, pH, the role of different sources of calcium carbonate. Some studies contradict themselves. My aim was also to point out these differences. Many of environmental factors are measurable with difficulties. Using of Ellenberg's indicator values seems to be an interesting alternative possibility to classical measurement. The importance of Křivoklátsko PLA is highlight as the landscape of continual forest development, which is unique within Central Europe.
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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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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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Summary of the taxonomy of the genus Helix.
Korábek, Ondřej ; Juřičková, Lucie (advisor) ; Král, David (referee)
Despite the genus Helix Linnaeus, 1758 (Gastropoda, Pulmonata) comprises large and common land snail species, it is rather neglected by taxonomists. A vast number of species and subspecies level taxa were described along 19th century, most of them currently not considered as valid. Nevertheless, there remain doubts about species delimitation. It is obvious, that there is great morphological variability in some species, but little is known about its taxonomic value. Today, about forty valid species are recognized. The diversity center of this genus is situated in northeastern Mediterranean. The distribution data of particular taxa are fragmentary and ecology of some species is largely unknown. No collections are still available from extensive areas, thus completion of field collecting can lead to changes in status of some taxa or perhaps even to description of new species. This work is based on the review of available literature and partly also on the study of collection materials. It provides a list of available names in the genus Helix in its present sense. The problems of traits used for species identification as well as weak points of current knowledge of diversity of the genus Helix are briefly discussed.
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