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The Land Snail Velocity
Veselá, Kateřina ; Říhová, Dagmar (advisor) ; Loužecká, Ivana (referee)
This bachelor thesis deals with the usage of Garden Banded Snail (Cepaea hortensis) and Grove Snail (C. nemoralis) in teaching; especially in speed measurement. It is also addressed to laboratory breeding of this genus and basic requirements of land snails during keeping in order to provide specimens suitable for teaching as well as speed measurements. Despite of the compliance with the requirements for successful breeding, some specimens created epiphragm (temporary lid built during unfavourable conditions). Part of the thesis is addressed to this issue: why snails build epiphragm and how to activate them. The speed measurement itself is approached from the two different point of views: how to adapt the environment for measurement and how to perform the measurement in theoretical concept; and how to perform the measurements itself in a school class or in home breeding. The thesis uses responses of the students, who performed the experiment at school and shared the information about their feelings from working with the snails. Those feelings of disgust or even fear are discussed in a separate chapter. Apart from usage of land snails for the subject of Biology, this thesis also elaborates their inclusion into several other subjects.
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Determination of gastropods of the genus Radix, the intermediate hosts of trematodes
Mikešová, Kateřina ; Beran, Luboš (referee)
Lymnaeid snails of the genus Radix are common freshwater molluscs of Europe. Formerly, the following species have been reported from the Czech Republic according to the morphology of the shell: R. auricularia, R. peregra, R. ovata and R. ampla. However, recent studies involving molecular data revealed that species determination based on traditional approaches employing morphology of the shell and gonads can be more complicated, confusing and not fully reliable. The shape of the shell is affected by particular life conditions of the snails and proves to be highly variable. The characteristics that can be found on gonads are dependent on the reproductive phase of the snail, and sometimes also on the presence of trematode larval stages, which can cause parasitic castration. Recently, molecular taxonomy is the most reliable approach, especially when a combination of sequences of mitochondrial and nuclear DNA is used. As molecular analyses are relatively time-consuming and expensive, some authors try to find some additional morphological features that could be used for determination of Radix snails in the field, without the need of demanding equipment. Problems in taxonomy and systematics of members of the genus Radix have a practical point in studies of trematode life cycles. From the view of human and...
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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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Mollusca of the Czech Republic
Rindtová, Dita ; Hlava, Jakub (advisor) ; Křivská, Daniela (referee)
The Bachelor work Mollusca of the Czech Republic deals with basic information about molluscs occurring in the Czech Republic. In the research part of my work I deal with the anatomy of their bodies, shells and life cycles characteristic for the main representatives. In general characterization the work mentions endangered species listed in the Red List. Furthermore, the research part deals with ecology focused on shellfish incidence depending on the conditions of the ecosystem, introduction, and the methods of mollusc importance to humans.
The aim of the practical part was a faunal survey of selected localities contaminated by a man. This research was carried out in selected localities near the town of Příbram. It was the firsta research focused on the incidence of molluscs in these areas. The methodology of sample collection was carried out according to common methods of collecting molluscs and it is more specified in the work.
The own research was focused on characterisation of the areas (5 localities) where the collection was carried out. Thus there was formed a systematic overview of acquired kinds of terrestrial representatives according to designated habitats, taxonomic classification and specific characterisation of the species. A total of 514 individuals were processed belonging to 26 species of molluscs. The most numerous family had Vrásenkovití (Discidae) where the number of representatives climbed to 82 individuals. On the contrary Oxychilidae family, Skleněnkovití (Vitrinidae) and Melampovití (Ellobiidae) occured the least. There was found only one individual of each family.
In the last part of my work I deal with comparison of my research to the previous research carried out in Kokořínsko Reserve. This area has similar climatic conditions and the features of the ecosystems. The result of the comparison corresponds to the variability of the species found here.
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