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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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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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Shells morphology of pearl mussel (\kur{Margaritifera margaritifera})
PŮBALOVÁ, Lenka
The aim of this study was to determine the differences of freshwater pearl mussels (Margaritifera margaritifera) originated from two geographically isolated areas according to morphological parameters and the age of dead freshwater pearl mussel Data were collected from four localities, i. e. from the two areas (Šumava: Blanice, Zlatý potok and Aš area: Bystřina and Rokytnice). The average length of shells was 95.8 mm, thickness 27.9 mm, height 43.4 mm. The ligament was eroded from 57 % and index (ration between thickness and length x 50) was on average 32 %. Thickness of the shells and the percentage of eroded ligament differed between the two areas. Both of these parameters were higher in Aš area. Other morphological parameters (length and height of the shells and the above mentioned index) were similar in both areas. Assessment of age according to the growth lines in the ligament was significantly higher than the evaluation using growth lines on the surface of the shells. Mean age of freshwater pearl mussels determined using growth lines in the ligament was 36 years old and on the surface of the shells was 30 years old. Age according to the growth lines in the ligament better correlated with the length of the shell than percentage of eroded ligament. Age of dead freshwater pearl mussel was comparable in both areas, however differed between localities. Rokytnice proved to be the most suitable habitat for freshwater pearl mussels according to the age estimation.
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Analysis of selected localities suitability for freshwater pearl mussel young stages in upper stretch of Vltava River
Myslivečková, Lenka ; Bílý, Michal (advisor) ; Alena, Alena (referee)
In the river basins of Teplá Vltava and Blanice in Šumava, samples of floating and deposited detritus were taken for the purpose of their physical and chemical analysis with the goal to identify suitable stations for the growth and development of juvenile specimen of freshwater pearl mussels. 6 locations in total were examined (5 in the river basin of Teplá Vltava, 1 in the river basin of Blanice) where bio-indicator tests were also conducted. In all these locations, samples were taken 3 times during the month of July and, in 1 location, once a month in the period from June to November. In the samples, the amount of Ca, P, K, Mg, Na, the proportion of organic component and the ratio C/N were determined. This analysis showed that short-term oscillations of the composition of detritus correlate, regarding their span, with seasonal changes. The dependence of such seasonal changes of detritus on the extent of the river flow rate was not proved. Differences in the amount of organic component, K, Mg, and the ratio C/N between floating and deposited detritus were found. In terms of qualitative composition, both types of detritus varied in the amounts of plant and inorganic particles. In comparison with available results from springs in the area of Blanice, the detritus from rivers differed significantly from the detritus originating in springs in the presence of faecal pellets, amorphous matter and plant particles.
The growth of freshwater pearl mussels was dependent on the water temperature in the river, a dependence on the tested parameters of detritus was not proved, varying trends, however, were discovered (e.g. higher content of P, better growth). Water temperature showed to be dependent on the horizontal profile: water temperature rises with the direction of the water flow and the content of organic component in the detritus decreases with the direction of the water flow. Other trends in the horizontal profile were discovered as well but they were not proved statistically. Based on biological indicators, the locality of Ovesná (the lowest point down the river Teplá Vltava) was assessed to be the most suitable station.
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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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Growth and survival of pearl mussel (Margaritifera margaritifera) for bioindication
NIEDLOVÁ, Eva
Growth and survival of juvenile pearl mussels (Margaritifera margaritifera Linnaeus, 1758) "in-situ" indicates suitable habitats for their rearing and subsequent reintroduction. Six streams in Aš region (Rokytnice, Lužní potok, Pekelský potok, Újezdský potok, Perlový potok, Bockbach) including 15 profiles were evaluated throughout the season (1. 6. 31. 8. 2015). One year old pearl mussels (n = 580) sized from 700 1400 ?m. Mean survival of pearl mussels was 63 % in all streams. Mean absolute growth increment attained 755 ?m throughout the season. Growth of pearl mussels (1+) was positively correlated with the water temperature (R2 = 0,1084). Both the highest survival (70 %) and the highest absolute growth (1027 ?m and 997 ?m) of pearl mussels was determined on localities in Bockbach (Bockbach 11 and 1). In contrast to Bockbach 11 and 1 mean survival (28%) and absolute growth (304 ?m) was the lowest in Lužní potok 2. Survival rate of two years old pearl mussels was higher than that of one year old pearl mussels. Both of these age categories grew similarly.
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Ichtyofauna of selected streams of Bohemian Forest
ŠRÁMEK, Jiří
Presented work is directed to summarize the results of ochtyomonitoring of five stream in Bohemian Forest in autumn 2010. The processing status is evaluated fish communities, especially their species composition, diversity, dominance, evenness and other parameters. They have been evaluated also physico-chemical properties of the sites such as air and water temperature, conductivity and turbidity. Last but not least were evaluated the characteristics of flows and in particular morphological characteristics, types of the bottom substrate and its contours etc. The evaluation of all obtained data showed that fish communities surveyed Bohemian flows are balanced, they are not burdened with invasive species and rand indicators correlated with the state of flow, geographic location and natural conditions. It was caught nine fish species in the total number of 963 individuals. Abundance was at all locations in the range 201,6 to 409,7 individuals per kilometer of flow, showed the diversity of communities from 0,372093 to 2,166085 (Shannon and Wiener index) and from 0,301804 to 0,866948 (Simpson index), then evenness of plant 0,372093 to 0,783906. The most dominant species was the brown trout, the second most frequent species was bullhead.
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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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