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Karyotype differentiation of the harvestmen belonging to the subroder Laniatores from South Africa
Marešová, Alexandra ; Šťáhlavský, František (advisor) ; Symonová, Radka (referee)
Current cytogenetic knowledge of the suborder Laniatores is only known for 11 species from South and North America. This study presents the first cytogenetic analyses of South African families Biantidae and Triaenonychidae which belong to the most diverse suborder of harvestmen. After analyzing the karyotype, variability in the diploid chromosome number was found, with Biantidae having 2n = 38-52 and Triaenonychidae having 2n = 28-64. Variability was also observed in the morphology of chromosomes. While both families predominantly exhibit bi-armed chromosomes, individual species show different representations of various morphological types. In addition to basic cytogenetic analyses, fluorescent in situ hybridization (FISH) was performed, revealing variability in the number and location of gene clusters for 18S rRNA. Using this method, the telomeric motif (TTAGG)n was also localized, which was present only at the ends of chromosomes in all analyzed species from both families. Key words: cytogenetics, harvestmen, Laniatores, FISH, 18S rRNA, karyotype variability
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Phylogeny and diversity of harvestmen suborder Laniatores
Marešová, Alexandra ; Hiřman, Matyáš (advisor) ; Dolejš, Petr (referee)
This bachelor thesis summarizes the general knowledge about phylogenesis, diversity and distribution of harvestmen from the suborder Laniatores. Until recently, phylogenetic relationships of this suborder were very few studied, but thanks to a recent studies they are still improving. The suborder Laniatores now includes 41 families, which are divided into ten superfamilies. An overview of distribution of individual families of the suborder Laniatores is also given in this work and so are factors influencing it. From abiotic factors there is humidity, temperature, climate, and altitude. Among biotic factors, the distribution may be influenced by the type of vegetation or by the human, where it is mainly the introduction of invasive species. The greatest emphasis is placed on morphological differences between individual families. The biggest differences can be observed on their bodies, especially in the form of different numbers and types of sclerotized protrusions. Keywords: harvestmen, Laniatores, phylogenesis, biogeography, biodiversity, morphology
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Karyotype variability of harvestmen from Nemastomatidae family (Arachnida: Opiliones)
Alaverdyan, Argam ; Šťáhlavský, František (advisor) ; Symonová, Radka (referee)
This master's thesis is focused on cytogenetic analysis and karyotype variability of the Nemastomatidae family. This family comprises morphologically uniform harvestmen of small sizes, with low mobility, and with center of distribution in Europe. Karyotype differences could play an important role for detection of cryptic diversity in this family. The karyotype analysis is focused mainly on Alpine and Pyrenean endemic species but also on other taxons located in Central Europe. The goal was not only to identify the differences which occur between the specific genera and species, but also eventually between populations. For detection of the specific chromosomal alterations in evolution of the karyotype in Nemastomatidae the fluorescent in situ hybridization (FISH) was used, localizing the positions and amounts of gene clusters for 18S rRNA. From the results we can assume that the number of chromosomes in the family Nemastomatidae can range between 2n = 12- 30. Further it was found out that in Nemastomatidae the biarmed chromosomes are more prevalent, and that the species which have lower amounts of chromosomes contain chromosomes that noticeably differ in size (probably because of chromosomal fusions). These results indicate that with some morphologically uniform species, the knowledge of specific...
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Biogeography of arachnofauna of the Alps
Šilhavá, Alena ; Šťáhlavský, František (advisor) ; Řezáč, Milan (referee)
This bachelor thesis gives a summarizing overview of the biogeography of arachnofauna of the Alps. It covers five orders of arachnids residing in the Alps, namely scorpions (Scorpiones), pseudoscorpions (Pseudoscorpiones), palpigrades (Palpigradi), harvestmen (Opiliones) and spiders (Araneae). The work is focused on the distribution of endemic and subendemic species of these orders of arachnids and on factors that can influence their distribution and total diversity in the Alps. It turns out that temperature and humidity are important factors. Pseudoscorpions occur more frequently in warmer areas at lower altitudes, while especially scorpions of the genus Euscorpius (Alpiscorpius) and harvestmen are more tolerant to areas with a lower temperature, while harvestmen especially require sufficient humidity. For spiders in the mountains of the Alps total species richness and density decreases mainly from open land to the forest. Total diversity in the Alps has also been influenced by temperature oscillations during the Quaternary climatic changes and different positions and types of refugia. This is apparent at the species closely related to soil environment, such as palpigrades or cave pseudoscorpions of the family Syarinidae. Key words: biogeography, the Alps, endemic, Scorpiones, Pseudoscorpiones,...
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