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Genome size variability and its relationship towards selected biological characteristics of arachnids
Šilhavá, Veronika ; Opatová, Věra (advisor) ; Urfus, Tomáš (referee)
Genome size, also called C-value, describes the amount of DNA contained in haploid set of chromosomes in organism. Knowledge of this value can be useful for example as indicator of technical difficulty and financial cost of projects using genome seqencing, or it can be used for taxonomic purposes as well. Genome size encompasses immense variability across the animal kingdom. We also encounter variability among arachnids, even between species within the same genus. However, the relationship between genome size and biological characteristics of arachnids has not been examined so far. In this thesis, I assembled genome size data for all arachnid orders alongside with a variety of their biological characteristics. These traits were subsequently mapped onto the phylogenetics trees. In certain arachnid orders, the genome size could be related to the body size, life span and potentially also to ecology (e.g. web type, retreat). Unfortunatelly, genome size data are available only for a small portion of Arachnida diversity, which complicates the interpretation.
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Use of cytogenetical methods in taxonomy of Arachnida (Arachnida)
Alaverdyan, Argam ; Šťáhlavský, František (advisor) ; Johnson Pokorná, Martina (referee)
This bachelor thesis deals with the use of cytogenetic methods in taxonomy of Arachnida. To understand this matter, we need to analyse available information about inter and intraspecific karyotype variability of individual orders. At the beginning of the thesis there is a description of cytogenetic methods used with Arachnida.They are used to gather the karyotype's fundamental information, such as the diploid number of chromosomes, chromosome morfology and possible occurence of sex chromosomes. Main part of the thesis is focused on describing karyotypes of selected orders (Amblypygi, Palpigradi, Pseudoscorpiones, Scorpions, Opiliones and Araneae) and considering the convenience of use of cytogenetic methods for their taxonomy based on these information. The thesis includes current number of described genera (species) of the orders, as well as a number of cytogenetically analyzed genera (species) for comparison.
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Adaptations of terrestrial arthropods and especially arachnids to arid environmental conditions
Byronová, Markéta ; Starostová, Zuzana (advisor) ; Opatová, Věra (referee)
The biggest problem that terrestrial animals have to deal with is the risk of dehydration. Water is lost by evaporation during respiration and through the body surface, during excretion and various secretions. Terrestrial animals developed various physiological, morphological and behavioral adaptations against water loss. This work summarizes the knowledge about adaptations against water loss in arthropods in arid environmental conditions. It focuses on arachnids and especially on scorpions, which are widespread in arid areas and show high resistance to extreme desert conditions. The work examines the influence of environmental conditions on physiological processes in the body, morphological adaptations and behavioral changes. It defines specific adaptations of scorpions and describes in more detail the role of the hepatopancreas in maintaining the balance of fluids in the body and the subsequent changes in the osmolarity of hemolymph. Key words: evaporation, aridity, water balance, arthropods, arachnids, scorpion
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Use of cytogenetical methods in taxonomy of Arachnida (Arachnida)
Alaverdyan, Argam ; Šťáhlavský, František (advisor) ; Johnson Pokorná, Martina (referee)
This bachelor thesis deals with the use of cytogenetic methods in taxonomy of Arachnida. To understand this matter, we need to analyse available information about inter and intraspecific karyotype variability of individual orders. At the beginning of the thesis there is a description of cytogenetic methods used with Arachnida.They are used to gather the karyotype's fundamental information, such as the diploid number of chromosomes, chromosome morfology and possible occurence of sex chromosomes. Main part of the thesis is focused on describing karyotypes of selected orders (Amblypygi, Palpigradi, Pseudoscorpiones, Scorpions, Opiliones and Araneae) and considering the convenience of use of cytogenetic methods for their taxonomy based on these information. The thesis includes current number of described genera (species) of the orders, as well as a number of cytogenetically analyzed genera (species) for comparison.
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Comparison of Arachnids from caves in selected parts of Balcanic and Alpine-Carpathian regions
Škopek, Zdeněk ; Šťáhlavský, František (advisor) ; Růžička, Vlastimil (referee)
This work presents comparison of cave arachnids in selected areas of Balcanic and Alpine-Carpathian regions. The work contains basic characteristics of studied regions, also characteristics of cave environment and explanation of important terms often used in relation to these habitats. Further, it concludes basic knowledge of all recent orders of arachnids to cave environment. It contains also detailed study of the best investigated groups of arachnids, and tries to explain some aspects, which influence the biodiversity on the matched area. Powered by TCPDF (www.tcpdf.org)
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Evolution of selected karyotype characters in tetrapulmonate arachnids
Jílková, Klára ; Král, Jiří (advisor) ; Marec, František (referee)
The class Arachnida is not thoroughly explored from the cytogenetic point of view. Previous studies suggest a high diversity of karyotypes and sex determination in arachnids. This study deals with the evolution of sex chomosomes, nucleolar organizer regions (NOR), and telomeric repeats in the tetrapulmonate clade of arachnids, particularly in groups of ancient origin. Sex chromosomes were detected in two orders. Detection of NORs in a large set of species supports the hypothesis that the ancestral karyotype of arachnids contained NOR on one pair of autosomes only. The number of NORs has increased during the evolution of some groups of Pedipalpi. The NORs are located in terminal or subterminal chromosomal regions in most tetrapulmonates. The occurrence of the "insect" telomeric motif was confirmed in majority of tetrapulmonates. Interstitital telomeric repeats were not detected with the exception of one species. Keywords: arachnids, meiosis, sex chromosomes, telomeres, nucleolar organizer, heterochromatin
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