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Habitat selection by dragonflies - effect of littoral and riparian vegetation
Bonková, Anita ; Černý, Martin (advisor) ; Waldhauser, Martin (referee)
Dragonflies form one of the important pillars of most aquatic ecosystems and play an important role in maintaining their balance. The main goal of this bachelor's thesis is to summarize current knowledge about the habitat preferences of members of the order Odonata, with a focus on the effect of littoral and riparian vegetation, which are critical components of aquatic biotopes and significantly influence the distribution, abundance and reproductive success of dragonflies. In my work, I focus on all developmental stages, from larvae to adults. These findings are important for the maintenance and revitalization of freshwater ecosystems, in which it is necessary to pay attention to the composition of littoral and riparian vegetation to support the diverse needs of this unique insect order. Key words: habitat preference, dragonflies, Odonata, riparian vegetation, littoral vegetation
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Dragonflies (Odonata) of selected localities around Benešov
ŘÍHOVÁ, Radka
This bachelor thesis aimed to map the presence of dragonflies (Odonata) in selected locations around the municipalities of Heřmaničky, Velké Heřmanice, and Mrákotice in Benešovsko. This Bachelor thesis is based on pre-conducted field research (dragonfly capture and observation). Another aim of this bachelor thesis was to investigate the natural conditions at eight pre-selected locations in Benešovsko, compare the sites with each other based on environmental characteristics, and find out the presence of dragonfly communities. It has made the suggestion even about didactic use in primary school teaching.
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Inovace chovu larev candáta obecného (Sander lucioperca L.) při použití vířníků druhu Branchionus plicatilis
IMENTAI, Aiman
Pikeperch (Sander lucioperca L.) has been realized as one of the promising candidates. Currently one of the crucial bottlenecks in pikeperch larviculture is larval first feeding when high mortalities occur. Since recognition of rotifers as potential candidate for larvae culture, its value has grown tremendously in fish hatcheries. Although using rotifers and Artemia as a starter food items has become a common practice in hatcheries, yet rotifers has not been used for pikeperch larval culture. Many questions regarding introduction of rotifers during pikeperch larval first exogenous feeding are still not answered. The aim of this Ph.D. thesis was to maximize survival, growth and fitness of pikeperch larvae during first exogenous feeding by using rotifers Brachionus plicatilis. The effects of B. plicatilis on survival rate, growth performance and fitness of pikeperch larvae during first feeding were evaluated in the first study. Larvae were reared under three different diets (Artemia; Art /rot; rotifers) from 3 till 17 days post hatch (DPH). Using rotifers as first diet for pikeperch larvae was shown to benefit survival and growth rates. Larvae fed on rotifers only or combined diet (rot/Art) obtained higher survival and growth compared to Artemia diet. It was found that essential fatty acids of rotifers and their smaller size had a crucial effect on the larval survival and performance. The findings of the first study showed that the mixed diet (rot/Art) could be recommended as innovated first exogenous feeding in pikeperch larvae. The objective of the second study was to optimize the first exogenous feeding regime for pikeperch larvae using rotifers and Artemia. Larvae were fed with rotifers for 3 days and afterwards from 8 to 17 DPH they were adopted to 5 different regimes. It was found that feeding pikeperch with rotifers from 5 to 8 DPH and afterwards exclusively with Artemia or mixed of rotifers and Artemia till 17 DPH can ensure high survival and growth rates, and better development of digestive organs. Feeding larvae with rotifers from 5 to 8 DPH and afterwards replacing with Artemia till 17 DPH is recommended as an optimum feeding regime because larval survival and growth were satisfying, and it reduces the costs for production. The main aim of the third study was to determine the optimal salinity for rearing of pikeperch larvae using B. plicatilis. Rotifers were stocked under different salinities and motility was investigated over a 6-h period. The same salinities were used in second trial of this study to quantify the effect on pikeperch gut fullness over the course of 11 h. In the third trail, the survival and growth rate of larvae from 4 to 11 DPH at low and medium salinities were analyzed. Results of this study showed that rotifers stocked at all tested salinities, except for freshwater retained motility for over a 6-h period. Pikeperch larvae reared at 2? and 4 ? showed higher survival and growth rate during trial compared to freshwater. The results of this study showed that larvae in low salinity water had higher survival and growth rate during initial exogenous feeding with B. plicatilis. The aim of fourth study was to determine the optimal rotifers density for pikeperch larvae at the beginning of exogenous feeding. Larvae were divided into 4 groups at different rotifers densities from 5 to 9 DPH. The best growth performance was achieved at the highest rotifers density, however survival rate did not significantly differ among the groups. The results suggested that B. plicatilis at density of 6 ind/mL can be considered optimal for larval growth from 5 to 9 DPH when balancing production and costs, compared to higher prey densities.
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Ontogeny, evolution & homology of cement glands and attachment organs in lower vertebrates
Minařík, Martin ; Černý, Robert (advisor) ; Ráb, Petr (referee) ; Buchtová, Marcela (referee)
Aquatic larvae of many vertebrate lineages develop specialized, cranially located cement or attachment glands which allow them to remain attached to a substrate by means of polysaccharide secretion. The larvae can thus remain still and safe in well-oxygenated water out of reach of any predators until the digestive and locomotory apparatus fully develops. Xenopus cement gland is the most thoroughly studied example of this type of glands, since it was used as a model for the anteriormost patterning of the developing head. Based on shared expression patterns of key transcription factors and a similar ectodermal origin it has been repeatedly suggested that Xenopus cement gland is homologous to adhesive organs of teleosts and adhesive papillae of ascidians. The lack of comprehensive knowledge on this type of glands in other lineages however rendered any considerations of homology among such a distant lineages rather inconclusive. In the present work I have focused on a detailed study of the cement glands and other corresponding structures in three representatives of basal actinopterygian lineages: Senegal bichir (Polypterus senegalus), sterlet (Acipenser ruthenus), and tropical gar (Atractosteus tropicus). Using a combination of in vivo fate-mapping approaches with a Micro-CT imaging of cranial endoderm...
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Developmental morphogenesis of attachment organs in lower vertebrates
Minařík, Martin ; Černý, Robert (advisor) ; Buchtová, Marcela (referee)
Adhesive organs are widespread structures among vertebrate larvae. They allow the larvae to attach to a substrate, so that the time for the development of mouth or motoric apparatus could be prolonged. Similar structures in ascidians, larvaceans and lancelets are known too. Thus, it might be hypothesized that the presence of some type of adhesive gland could indeed represent the ancestral state for chordate larvae. Interestingly, however, whilst in most species these glands take their developmental origin in ectodermal layer, in bichir, a member of a primitive actinopterygian lineage, their origin was suggested to be endodermal already at the beginning of 20th century. Since then, however, the former study has become almost forgotten and even recent analyses do not come with new findings on this topic. Because of the essential importance of study of bichir cement glands for understanding the relationship between these structures among chordates, I have decided to focus on this subject. To obtain appropriate comparative data Xenopus, Weather loach and Ribbed newt embryos were included in this study as well. By using combination of immunohistochemical and histological techniques the endodermal origin of cement glands in bichir was proven and their morphogenesis was described into considerable details. The...
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Ontogeny, evolution & homology of cement glands and attachment organs in lower vertebrates
Minařík, Martin ; Černý, Robert (advisor) ; Ráb, Petr (referee) ; Buchtová, Marcela (referee)
Aquatic larvae of many vertebrate lineages develop specialized, cranially located cement or attachment glands which allow them to remain attached to a substrate by means of polysaccharide secretion. The larvae can thus remain still and safe in well-oxygenated water out of reach of any predators until the digestive and locomotory apparatus fully develops. Xenopus cement gland is the most thoroughly studied example of this type of glands, since it was used as a model for the anteriormost patterning of the developing head. Based on shared expression patterns of key transcription factors and a similar ectodermal origin it has been repeatedly suggested that Xenopus cement gland is homologous to adhesive organs of teleosts and adhesive papillae of ascidians. The lack of comprehensive knowledge on this type of glands in other lineages however rendered any considerations of homology among such a distant lineages rather inconclusive. In the present work I have focused on a detailed study of the cement glands and other corresponding structures in three representatives of basal actinopterygian lineages: Senegal bichir (Polypterus senegalus), sterlet (Acipenser ruthenus), and tropical gar (Atractosteus tropicus). Using a combination of in vivo fate-mapping approaches with a Micro-CT imaging of cranial endoderm...
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Developmental morphogenesis of attachment organs in lower vertebrates
Minařík, Martin ; Černý, Robert (advisor) ; Buchtová, Marcela (referee)
Adhesive organs are widespread structures among vertebrate larvae. They allow the larvae to attach to a substrate, so that the time for the development of mouth or motoric apparatus could be prolonged. Similar structures in ascidians, larvaceans and lancelets are known too. Thus, it might be hypothesized that the presence of some type of adhesive gland could indeed represent the ancestral state for chordate larvae. Interestingly, however, whilst in most species these glands take their developmental origin in ectodermal layer, in bichir, a member of a primitive actinopterygian lineage, their origin was suggested to be endodermal already at the beginning of 20th century. Since then, however, the former study has become almost forgotten and even recent analyses do not come with new findings on this topic. Because of the essential importance of study of bichir cement glands for understanding the relationship between these structures among chordates, I have decided to focus on this subject. To obtain appropriate comparative data Xenopus, Weather loach and Ribbed newt embryos were included in this study as well. By using combination of immunohistochemical and histological techniques the endodermal origin of cement glands in bichir was proven and their morphogenesis was described into considerable details. The...
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Inovativní metody v chovu a reprodukci candáta obecného (Sander lucioperca)
BLECHA, Miroslav
The whole Ph.D. thesis includes in total 10 chapters on 146 pages. Chapter 2 9 are specific parts of thesis where following scientific and practical aspects of pikeperch reproduction biology and aquaculture are described. Quality and quantity of pikeperch spermatozoa after varying cold water treatments are presented in the chapter 2 and can help to optimize broodstock management of males with the aim to obtain high quality spermatozoa during a seasonal and an out of season spawning as well. Benefits of hormone treatment of both sexes in semi-artificial reproduction in pikeperch are described in the chapter 3 where the importance of hormonal treatment of both sexes in tank spawning is evaluated for effective production pikeperch larvae. The use of an alcalase treatment for the elimination of pikeperch egg stickiness is being shown in the chapter 4 of this thesis. Post-ovulatory oocyte ageing and its effect on eggs viability rates and occurrence of larval malformations and ploidy anomalies are listed in chapter 5. These results describe the effects of the egg over ripening fertilization process in pikeperch. The first report of heat shock triploidisation in pikeperch is described in chapter 6 with production of 100% pikeperch triploid population. The effect of water surface treatment on survival, swim bladder inflation and growth of larvae is given in the chapter 7 with the aim to optimize the intensive culture of pikeperch larvae. Last two chapters (8 and 9) are describing the adaptation of intensively cultured juveniles to pond culture and the adaptation of pond-cultured juveniles to RAS as a new and effective methods for ongrowing production of pikeperch. In total, four published scientific papers, one handbook, one accepted scientific paper for publication, and two prepared scientific manuscripts are included and discussed in this Ph.D. thesis.
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Cold adaptation of insects: the role of shock proteins from Hsp family.
ŠTĚTINA, Tomáš
Heat shock proteins (Hsps) form evolutionarily conserved group of proteins that are best known for their unique function in repair of miss folded proteins that would otherwise aggregate in cells during stress conditions. The most extensively studied is the inducible Hsp70. Using 3rd instar larvae of transgene mutant of fruit fly, Drosophila melanogaster that lacks all copies of hsp70 gene, we assessed: 1) whether the absence of this gene is deleterious for larvae in their capacity to survive cold stress; and 2) whether any other gene from Hsps family may compensate for the loss of hsp70. We found that 1) survival of cold stress is not altered in Hsp- larvae when compared to wild type Hsp+ larvae; 2) there is no other gene of Hsps family that would compensate for the loss of hsp70 at the level of transcription. Our ongoing effort is focusing on analysis of cold stress response at the protein level.
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