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Seasonal variation of activity and pathogen prevalence in populations of the spiny-cheek crayfish
Matasová, Klára ; Petrusek, Adam (advisor) ; Slavík, Ondřej (referee)
The most widespread of invasive crayfish in the Czech Republic is the spiny-cheek crayfish (Orconectes limosus). It is a major disease carrier of crayfish plague, caused by the pathogen Aphanomyces astaci. The infection is lethal to European native species of crayfish. Transmission of this disease is usually associated with the spread of crayfish, which is dependent on their movement. The main aim of this work was to evaluate the differences in crayfish migratory activity in the Pšovka brook among seasons, and assess the factors that may affect it, by the use of radiotelemetry and trapping. We tested the hypothesis that crayfish use brook in the period from spring to autumn and then return back into a pond to overwinter. Furthermore, we evaluated how far from the pond crayfish migrate, and whether there is any relationship between migration and the season or water temperature. The results demonstrate that the activity varies among seasons (being strongly affected by breeding season) but in most studied periods did not significantly depend on water temperature. According to our monitoring, the spiny-cheek crayfish does not spread substantially to upstream parts of the Pšovka. Seasonal migration between the pond and the brook was monitored using two-way flow-through traps installed at the mouth of...
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Seasonal variation of activity and pathogen prevalence in populations of the spiny-cheek crayfish
Matasová, Klára ; Petrusek, Adam (advisor) ; Slavík, Ondřej (referee)
The most widespread of invasive crayfish in the Czech Republic is the spiny-cheek crayfish (Orconectes limosus). It is a major disease carrier of crayfish plague, caused by the pathogen Aphanomyces astaci. The infection is lethal to European native species of crayfish. Transmission of this disease is usually associated with the spread of crayfish, which is dependent on their movement. The main aim of this work was to evaluate the differences in crayfish migratory activity in the Pšovka brook among seasons, and assess the factors that may affect it, by the use of radiotelemetry and trapping. We tested the hypothesis that crayfish use brook in the period from spring to autumn and then return back into a pond to overwinter. Furthermore, we evaluated how far from the pond crayfish migrate, and whether there is any relationship between migration and the season or water temperature. The results demonstrate that the activity varies among seasons (being strongly affected by breeding season) but in most studied periods did not significantly depend on water temperature. According to our monitoring, the spiny-cheek crayfish does not spread substantially to upstream parts of the Pšovka. Seasonal migration between the pond and the brook was monitored using two-way flow-through traps installed at the mouth of...
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Freshwater mussels breeding methods for the purpose of conservation programs
Plechingerová, Věra ; Douda, Karel (advisor) ; Matasová, Klára (referee)
Bachelor thesis is written in an overview form of problems breeding freshwater molluscs. At the beginning of the thesis I first evaluate the overall status of the populations in the Czech Republic and then in the world. Next I describe the anatomy and biology of molluscs, especially their reproduction, which is crucial for rearing juveniles in the laboratory or seminatural environment. The return of molluscs populations into the waters ecosystems is problematic in terms of ongoing changes in the biotope, particularly because of the anthropogenic influences and too few suitable host fish, without which it can not complete its glochidia development. To prevent the complete extinction of some species, there have been researched different methods of rearing, which help recover viable populations in the natural water environment. Methods of rearing are also described in this thesis. In the experimental part of the thesis I evaluate types of detritus that have different effects in length gain of mussels. For the experiment was selected freshwater pearl mussel (Margaritifera margaritifera), whose population is highly endangered. Freshwater mussels are an important bio-indicator of waters ecosystems, where they have an irreplaceable function, so it is important to regenerate their populations and the overall condition of the biotopes.
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The growth and survival of juvenile freshwater pearl mussel in respect to food resources
Mastíková, Jana ; Douda, Karel (advisor) ; Matasová, Klára (referee)
The survival of the freshwater pearl mussel (Margaritifera margaritifera) depends on the protection and preservation of the suitable biotypes that is why it is necessary to know its requirements for environmental conditions. This species indicates the quality of suitable biotypes with its specific requirements for food and environment. During its life, the freshwater pearl mussel is undergoing complicated development cycle and in each phase it has different requirements for food. In the juvenile phase, it is very sensitive to quality of environment as well as quality and composition of its food, which consists of organogenic detritus, which is mainly decomposed mass of vegetable and animal origin together with bacteria. Its food arises in river basin areas as well as in river spring areas-from where it is carried downstream by a river and so pearl mussels may ingest it filtering the water.
This highly specialized species that is sensitive to environmental changes, especially within its juvenile life phase, is very important as to its bio-indicating ability. The experimental part of this work was focused on the evaluation of the detritus carrying-capacity performed by the bio-indication method ex-situ in a laboratory out of its natural environment. For evaluating the carrying-capacity and quality of the tested detritus under optimal temperature conditions ex-situ for 10 days, there were used juvenile pearl mussels from a semi-natural breeding. The tested samples of detritus were collected according to the standard procedures in the summer 2015 from the locality of Blanice river spring area. There were collected totally 100 samples of detritus from 100 spring areas. The goal was to evaluate the growth of shells of juveniles depending on physico-chemical properties of the sample. The main analyzed data were the value of the pearl mussel growth and detritus parameters - pH, conductivity and altitude of the springs.
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Possibilities for bioindication of the surface water status using freshwater bivalves’ shells with focus on the morphological variability of Unio crassus
Zuzáková, Hana ; Douda, Karel (advisor) ; Matasová, Klára (referee)
Possibilities for bioindication of the surface water status using freshwater bivalves shells with focus on the morphological variability of Unio crassus
Summary
This bachelor thesis present a review of scientific literature dealing with the possibilities for bioindication by freshwater mussels of the family Unionidea. In it practical part, it is about the variability of freshwater mussel Unio crassus, whose shells were collected from 10 streams in Poland, Bulgaria and Romania. Specifically, shells from 357 U. crassus individuals were measured by classical morphometric method. This analysis confirmed findings from literature where are mentioned most common size of shells (40- 70 mm of length). Using residual values of the relationship between shell length and width and between shell length and the thickness the shell shapes were compared between individuals and the watersheds with the use of basic statistical methods, scatterplots and boxplots.
The result is a significant value for different flows, their differences are only in the few millimeter variance. For a substantial variation in shapes were made GIS analysis for each river. To describe the catchment area were delineated buffers in the size of square root lengths of streams, in which was to determine land-use and their percentage and surface representation. Land-use categories were characterized by Corine Land Cover classes. Identified categories in studied areas include total afforestation total artificially built-up areas, agricultural and water areas.
The resulting statistics of land use were compared and evaluated in relation to the shape characteristics of U. crassus and enabled the determination of species plasticity and variability which is capable, despite their demands and the need for high quality waters, live in diverse environmental conditions. Despite the limited set of population tested, study documents that typical environmental conditions for U. crassus are unpolluted areas with a high percentage of afforestation, the average representation of agricultural land, and the lowest representation of any built-up areas and industrial application in the nearby stream.
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Landuse efects on the temperature regime of streams with focus on the habitat conditions for Margaritifera margaritifera
Skála, Miroslav ; Douda, Karel (advisor) ; Matasová, Klára (referee)
Landuse efects on the temperature regime of streams with focus on the habitat conditions for Margaritifera margaritifera
Summary
This bachelor thesis deals with the matter of the freshwater pearl mussel (Margaritifera margaritifera). It will describe the main factors affecting its reproduction and presence in the watercourse - the fresh pearl mussel is to be found among the endangered species and its presence and survival in a certain location depend primarily on the hosting fish which is the brown trout here in the Czech Republic. Generally, the main stress lays on the temperature and its influence on the ecology of the freshwater pearl mussel. This thesis contains a research part which describes the freshwater pearl mussel and impacts on it, and a practical part where you can find an assessment of the temperature and qualitative impact on growth and death of the freshwater pearl mussel during bioindications.
The temperature influences all age stages of the freshwater pearl mussel. The temperature changes thanks to a variety of different aspects such as surrounding flora in the watercourse, atmospherical factors, anthropogenic activity or altitude. You will be able to find all these aspects along with a percentage of their potential effect on the freshwater pearl mussel in this thesis as well as the assessment of the average summer temperature and its possible impact on any specimen of any stage.
The thesis is also based on the impact of surroundings on the freshwater pearl mussel which are discovered during bioindications that are also described here and have been partially used in the appraisal. The practical part of the thesis is focused on the growth and death of the species in the bioindication in five profiles of the watercourse.
The third part of the practical thesis is about locations that show surroundings and representation stated components. The reason I included this part is mostly for illustrative purposes which serve to expound the matter to the reader. The used data of components in the locations are from 2012.
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