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Biology of gall wasps (Diplolepis spp.) (Hymenoptera: Cynipidae) in palearctic region
Vitáček, Jakub ; Janšta, Petr (advisor) ; Holý, Kamil (referee)
This bachelor thesis is focussed on description of biology of gall wasps from the genus Diplolepis spp. (Hymenoptera: Cynipidae) in the palearctic region with the emphasis on some interesting phenomenons in their life cycle. These wasps induce galls obligatory on roses (Rosa spp.) and are widely distributed in the holarctic region. Many authors focussed on research of parasitoids, which use wasps larvae as food source. It was also recognized that inquilines lost their ability to induce own galls. However, their development is still dependent on galls tissues, because they feed on cells within galls. Rose gall wasps reproduce mostly without any mating. Female lay unfertilized eggs and males are very rare. Recently, development of modern techniques enable authors to study infection by bacteria of the genus Wolbachia and its role in the wasps parthenogenetic development. It is also apparent difference between the levels of our knowledge about individual species in this bachelor thesis. We have relative rich knowledges about European rose gall wasps, on the other hand biology of some Asian species is still very poor.
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Biogeography and specificity of Asterochloris photobionts
Řídká, Tereza ; Škaloud, Pavel (advisor) ; Vondrák, Jan (referee)
This diploma thesis has focused on the diversity and biogeography of Asterochloris photobionts. Since no study so far has been published on the biogeography of symbiotic microorganisms, the presented thesis is the first attemp to trace the biogeographic distribution and endemism of symbionts. By gathering 121 Asterochloris sequences obtained from lichen thalli sampled outside Europe and America, the diversity within the genus increased dramatically. The phylogenetic analysis based on the concatenated alignment of ITS rDNA and actin sequences obtained from Cladonia and Stereocaulon photobionts revealed 28 differently supported clades. Of them, eight lineages were newly discovered. Three environmental factors explaining the best the distribution pattern of Asterochloris photobionts were selected according to the statistical tests of the phylogenetic signal: two different types of biogeographical ecoregions and the substrate type. In general, the genus Asterochloris is distributed cosmopolitally, with a very low rate of endemism. Newly obtained data indicate that the restricted distribution of any photobiont clade is not caused by either historic or biological factors, but more likely by specific climatic or habitat preferences.
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Epiphytic species of the Lecanora subfusca group in the Czech Republic
Malíček, Jiří ; Palice, Zdeněk (advisor) ; Guttová, Anna (referee)
- 4 - ABSTRACT During the revision of epiphytic species of the Lecanora subfusca group in the Czech Republic, nine taxa have been recorded. L. cinereofusca and L. exspersa are reported for the first time from the country. L. circumborealis has been excluded from the list of Czech lichens. L. cinereofusca and L. horiza could be considered as extinct. L. rugosella and L. subrugosa are regarded as extreme morpholocial forms from L. chlarotera and L. argentata. These morphotypes corelate with ecological conditions: substrate (nutrient enriched bark) and habitat (eutrophisation effect). In case of L. subrugosa, this speculation was confirmed by molecular data (ITS rDNA sequences). Several new secondary metabolites have been discovered during the detailed research of chemical lichen compounds. These substances belonging to terpenoids are taxonomically important and very helpful for distinguishing single species. The abundance of L. allophana and L. chlarotera has decreased during last decades. Contrarily, L. pulicaris expanded slightly. The main reasons of changes in distribution are air pollution and acidification of substrates as the impact of acid rains. The rate of substrate acidification has been shown on example of L. pulicaris. In the past, this lichen predominated on acid-barked porophytes. Nowadays, it...
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Small mammals in diet of barn owl in the Eastern Meditarranean
Šindelář, Jiří ; Horáček, Ivan (advisor) ; Anděra, Miloš (referee)
The extensive material of skeletal remains of mammals from a diet of barn owl in the eastern Mediterranean has been processed and evaluated with different techniques of chorological and morphometric analysis. At least 8400 individuals of 45 species of insectivores, rodents and bats were found in our total collection of samples, which represents a significant portion of fauna of the region. We have evaluated a chorological composition of the taphocoenoses and the interregional differences, manifested primarily by differences in the representation of satellite and accessory elements. We found a highly significant impoverishment of the isolated island taphocenoses (Cyprus, Karpathos, partly on Crete), where Cricetidae, Arvicolidae, C. leucodon etc. are missing. On the other hand the essential part of the dominance structure takes up the Rattus rattus, which acts here as an invasive species, significantly more successful than in the ragged continental contexts. The species diversity of the examined samples is positively correlated with the geographic latitude (taphocenoses of the northern regions are significantly richer) and negatively with the island effect and the degree of aridization. The morphometric analysis of the three most abundant species of Soricidae within the studied region showed...
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Vertical migration of benthic cyanobacteria and algae
Mensa, Jakub ; Neustupa, Jiří (advisor) ; Němcová, Yvonne (referee)
Vertical migration has been observed in different taxonomic groups of benthic microalgae and cyanobacteria in both marine and freshwater habitats. It seems to be an advantageous survival strategy of motile photoautotrophic organisms. In general, algae inhabiting tidal environments migrate up to the sediment surface during daytime emersion and then migrate below the surface prior to high tide or dusk. Freshwater microalgae stay on the surface during daytime and migrate below the surface before dusk. The migratory rhythm can be controlled or influenced by light, waves, subsurface nutrient supplies and reducing conditions in the sediment. Sometimes, the rhythm persists even in constant conditions and it seems to be controlled by biological clock system.
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Ontogeny of trilobites
Laibl, Lukáš ; Fatka, Oldřich (advisor) ; Budil, Petr (referee)
The thesis summarizes the current state of knowledge about the ontogeny of trilobites. The introductory chapters describe the basic morphology and anatomy of trilobites, and also mention their ecology, occurrence and feeding habits. In the main part of my thesis, I first summarized the existing research in this area, and also dealt in detail with methods of preservation of trilobite larvae, their reproduction, growth, embryology, postembryonal development, segmentation and ecology. I also mentioned the possible usage of this knowledge in other fields (stratigraphy, biogeography, etc.). The last section is a contemporary view on the systematics of trilobites and their position within the Arthropoda.
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Behavioral ecology of reproduction of a bat, Myotis myotis.
Porteš, Michal ; Horáček, Ivan (advisor) ; Benda, Petr (referee)
Order Chiroptera is characterized by great variability in foraging, roost and social strategies. Polygamy is the most common mating system in this order and resource-defence polygyny is a typical strategy used by most of bats. The source which male defends is represented by roost and territory or by females in case of harems. Another strategy is represented by multi-male and multi-female autumn meeting at so-called swarming sites. With relatively non-specialized forms, the genus Myotis is widespread all over the world except arctic regions and is found in great number of biotops including tropical mountain forests and subarid regions. M. myotis and M. blythii/oxygnathus are two cryptic species which can be distinguished in morphological, biogeographical and ecological parameters. In central Europe, M. myotis uses synantropic roosts and recently started to use a highway bridges, mainly in autumn. Seasonal organization of population represents typical temperate cycle. The organization of maternity colonies reacts on different thermal conditions by changing aggregation in order to stay in thermal optimum. There is an intensive communication between females and juveniles in maternity colonies as well as between males and females in mating sites. Although that M.myotis is intensively studied in Europe,...
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Flatworms (Platyhelmintes: Tricladida) in the Czech Republik
Reslová, Marie ; Juřičková, Lucie (advisor) ; Buchar, Jan (referee)
This work focuses on the freshwater triclads and summarizes information about species occurring in the Czech Republic. Particular chapters concerned generally with taxonomy, anatomy and ecology of triclads; morphology, ecology and occurrence of each species is discussed in detail. 17 triclad species were recorded in the Czech Republic before now, some of them are considered as endemics. The majority of common triclads is determinable according to the head shape, but determination of Dugesia lugubris, D. polychroa a Polycelis nigra, P. tenuis is possible only based on the penis morphology. Some species can be regard as bioindicators, because of their narrow ecological requirements: cold water with high content of O2 - Dugesia gonocephala, Crenobia alpina, Polycelis felina; higher concentration of Ca2+ - D. gonocephala, Phagocata vitta, Planaria torva; oligotrophic standing waters - Polycelis nigra; eutrophic standing waters - Dugesia polychroa, Polycelis tenuis. Species of underground waters and springs are interesting and still unexplored ecological group of triclads.
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