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Fragmented populations of freshwater pearl mussel (Margaritifera margaritifera) in nonwadable rivers in Czech Republic
Zolich, Radek ; Simon, Ondřej (advisor) ; Korábek, Ondřej (referee)
Margaritifera margaritifera is a critically endangered species of freshwater bivalve. The protection status is regulated by both the legislation of the Czech Republic and local regulations. The aim of this thesis was to map the current occurrence of M. margaritifera in Czech streams and to verify assumptions about its occurrence in Otava near Horažďovice. Furthermore, the parameters of the shells of dead individuals, which are in the collections of the National Museum in Prague and the Czech University of Life Sciences, were also measured. A total of 642 shells collected from the Vltava, Teplá Vltava, Malše and Otava were available, while only the relevant part, specifically 509 shells, were used for separate evaluation. Differences in the morphological parameters of the shells depending on the locality and their possible correlation with the stream order of the Otava, Vltava, Teplá Vltava and Malša were investigated. Thanks to the findings from the mapping of living freshwater pearl mussels, a proposal was drawn up to modify the methodology of bivalve research in the Czech Republic, which is part of the Rescue program of freshwater pearl mussels, led by the AOPK of the Czech Republic. Key words: Freshwater pearl mussel, shell, morphology, stream order, AOPK methodology, diving operations
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Relationship between the age of freshwater pearl mussel and the number of increments in shell section
TOMAN, Jan
The aim of this thesis was to determine the relationship between the age of dead individuals of the freshwater pearl mussel (Margaritifera margaritifera) and the number of incremental lines on the shell section. A total of 124 pearl mussel shells of known age were collected from several Czech, German and Finnish localities. There was a statistically significant difference between the actual age and the age according to the number of incremental lines on shell section. On average, the age determined by increment lines was higher than the actual age by 2.6 years, which is 42 ? 25% (? S.D.). Thus, the increment lines on the section of the pearl mussel shell do not correspond to the annual increments. It was confirmed that increment lines count on the shell surface or estimating age from shell size are less reliable approaches to determine the true age of individuals.
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Calcium volume and ratio effect in food of freshwater pearl mussel (Margaritifera margaritifera) on its survival and growth rate
Macháček, Vojtěch ; Horáčková, Jitka (advisor) ; Tichá, Kamila (referee)
The freshwater pearl mussel (Margaritifera margaritifera) is a protected critically endangered species in the Czech Republic, whose juvenile stages are currently unable to survive and grow on many streams, partly due to the absence of quality food with sufficient calcium supply. Pearl mussels only live in oligotrophic rivers and streams, which are generally poor in calcium. However, they need enough calcium in their food, as they use it, among other things, to build a hard shell. It is not yet clear in what form pearl mussels take calcium in their diet, but it is clear that some of its forms are a key factor for the growth and survival of juveniles. We therefore focused on the study of various forms of organic calcium in their diet (fine particulate organic matter, further shortened as "detritus") and further feeding experiments to evaluate their suitability. Within this work, detritus was collected in thirty-five localities in the upper Vltava and Blanice river basins in three seasons in two years. Samples originated both from main river channels, their tributaries and springs. Afterwards, two organic forms of calcium in the samples - citrate and oxalate - were quantified. Then, twenty localities with different contents of both forms of calcium were selected from the tested samples, from which...
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Limit factors for survival of Unionoidea in the freshwater hyporeal with a focus on Margaritifera margaritifera
Macháček, Vojtěch ; Horáčková, Jitka (advisor) ; Barák, Vojtěch (referee)
This bachelor thesis deals with physical, mechanical, chemical and biological factors that limit the occurrence, survival and reproduction of large bivalve molluscs of the Unionoidea superfamily. Accent is placed on freshwater pearl mussel (Margaritifera margaritifera) for which a rescue action plan is being implemented in the Czech Republic, as it is one of the most endangered bivalve mollusc in our country and in Europe. In addition to the already thoroughly explored factors as - water temperature, conductivity, river dynamics, river bed structure, pH, concentration of various forms of nitrogen, phosphorus and oxygen, and the interaction of large bivalve molluscs with other animals, I deal with relatively new issues of pesticides and pharmaceuticals. These are appearing in the streams due to human (in)activity, and we know almost nothing about their impact on large freshwater bivalve molluscs. I also deal in more detail with the issue of calcium, which is essential for bivalve molluscs, because they make their shells out of it, although it is not yet clear which form they accept.
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Limit factors for survival of Unionoidea in the freshwater hyporeal with a focus on Margaritifera margaritifera
Macháček, Vojtěch ; Horáčková, Jitka (advisor) ; Barák, Vojtěch (referee)
This bachelor thesis deals with physical, mechanical, chemical and biological factors that limit the occurrence, survival and reproduction of large bivalve molluscs of the Unionoidea superfamily. Accent is placed on freshwater pearl mussel (Margaritifera margaritifera) for which a rescue action plan is being implemented in the Czech Republic, as it is one of the most endangered bivalve mollusc in our country and in Europe. In addition to the already thoroughly explored factors as - water temperature, conductivity, river dynamics, river bed structure, pH, concentration of various forms of nitrogen, phosphorus and oxygen, and the interaction of large bivalve molluscs with other animals, I deal with relatively new issues of pesticides and pharmaceuticals. These are appearing in the streams due to human (in)activity, and we know almost nothing about their impact on large freshwater bivalve molluscs. I also deal in more detail with the issue of calcium, which is essential for bivalve molluscs, because they make their shells out of it, although it is not yet clear which form they accept.
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Assessment of age and growth increments of pearl mussel (\kur{Margaritifera margaritifera}) shells
HOLEČKOVÁ, Karolína
The aim of the diploma thesis was to assess the quality of localities and their suitability for possible juvenile reintroduction based on the morphometric parameters and the age of dead freshwater pearl mussels (Margaritifera margaritifera). The age of the dead individuals was determined from the stained cross section of pearl shell layer. Shells were sampled on localities in Aš (Bystřina, Lužní potok, Rokytnice and Újezdský potok) and Šumava (Blanice, Kleine Ohe and Zlatý potok) in the Czech Republic and in the adjacent parts of Germany in 2015 and 2017. A total of 77 shells were used. Shells of larger sizes were found out in the Aš region. The average age of the shells was 46 years and did not differ between the regions. The average annual increments did also not differ between regions. It was 72,5 ?m.year-1. Shells of individuals originated from Rokytnice and Újezdský potok reached the highest age and had the greatest annual increments. Shells of individuals originated from Zlatý potok reached the lowest age and their annual increments were the lowest.
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The Fish Populations in the Selected Sumava Mountains streams with an occurrence of the Freshwater Pearl mussel
LUNDA, Roman
Monitoring of fish populations was done in 2010. The catch was conducted at predetermined locations with a potential occurrence of the freshwater pearl mussel (Margaritifera margaritifera). The aim was to map there ichtyofauna in terms of biodiversity, equitability, abundance, dominance and the size variation. An electric aggregate catching was used for the monitoring. Each section of the monitored area was 200 m long and catching was proceed upstream in its whole width. Caught fish were determined, measured and returned back. The status of fish communities was assessed on the basis of acquired information. In total, two species of Salmonidae and Cottidae were found in the monitored localities and one species of Cyclostomata. The dominating brown trout (Salmo trutta m. fario), (81.4%) was followed by the bullhead (Cottus gobio), (17.4%). The brook lamprey belongs to the next protected and endangered species. In terms of biodiversity the locality no. 8 Spulka ? upper part (0.59) was assessed as the first one while the locality no. 2 Zlaty potok (Golden stream) ? Miletinky (0.14) was at the last placing. A majority of these localities? community was formed only by the brown trout and the bullhead. Only one part of the locality no. 3 Zlaty potok ? Strunkovice had a community enriched by the brook lamprey. The most abundant freshwater pearl mussels were confirmed at the locality no. 2 Zlaty potok ? Miletinky where the freshwater pearl mussel occurs from tens to hundreds individuals. This part has also a high abundance of the brown trout (96.8%) which serves as the host fish for the freshwater pearl mussel?s evolution cycle.
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Fish Management in the Locations with Occurence of Freshwater Pearl Mussel (Margaritifera margaritifera) in the Czech Republic
JIRUŠKOVÁ, Lenka
Quality of populations of brown trout (Salmo trutta m. fario) influence of occurence of freshwater pearl mussel (Margaritifera margaritifera) in river in the Czech Republic. Freshwater pearl mussel is a critically endangered species of animals. It does not have a very specific requirements only on environment but mainly on a specific host for holding glochidia (larval stage of pearl mussel). Thus fish management and migratory permeability of flow for support of existing populations is very important. Basic and essential precondition to support populations of freshwater pearl mussels is the presence of viable populations of brown trout, which represents the only suitable host glochidia. There are five locations with the biggest occurrence of pearl mussel in the Czech Republic - river basins the Blanice, the Teplá Vltava, the Malše, the Rokytnice and the Jankovský potok. The management of these flows is under local organizations of Czech Fishing Union, the National Park and Protected Landscape Area of the Šumava, the Secondary School of Fisheries in Vodňany and Faculty of Fisheries and Protection of Waters. The present management was found in the questionnaire for representatives of farming organizations. According to the answers in the questionnaire, the change of plans of restocking was recommended in the river basins of the Teplá Vltava and the Jankovský potok. There is the cooperation with the Germany was recommended in the river basin of the Rokytnice. The restoration of fish nursery is suitable in the river basin of the Malše. There is the first-rate population of brown trout in the river basin of Blanice, thus the continue in the present fish management for next support of this population in sequence on the populations of freshwater pearl mussel was recommended
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