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Biogeography and host spectrum of twisted-wings (Strepsiptera)
Benda, Daniel ; Straka, Jakub (advisor) ; Malenovský, Igor (referee)
Twisted-wings (Strepsiptera) are an endoparazitic order of insects with cosmopolitan distribution, which are sister group of Coleoptera. There are 7 known host insect orders. As a group with relatively small number of species (almost 600) and cryptic way of life, Strepsiptera were usually overlooked by entomologists. Majority of publications about Strepsiptera deal simply with describtion of new species. For many taxa of basal families, the host group is unknown, because just free flying male has been collected and described. In contrary, only a female collected with host is known in some species. In derived families Xenidae and Stylopidae (parasitize Hymenoptera: Aculeata), there are known hosts in overwhelming majority of species. Many information about distribution of these groups can be extracted also from publications about hosts, where stylopized individuals are mentioned. Presented thesis summarizes the distribution of Strepsiptera at the level of families and genera. It also provides an assessment of the occurrens of Strepsiptera in different biogeographic regions with focus on their hosts. Keywords: Twisted-wings, Strepsiptera, distribution, parasites, host group, biogeography
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Diversity, distribution, phylogeny and ecology of the genus Micrasterias (Desmidiales)
Trumhová, Kateřina ; Šťastný, Jan (advisor) ; Bestová, Helena (referee)
The genus Micrasterias comprises one of the most beautiful organisms. It attracts, due to its spectacularly shaped cells, the attention of scientist and amateur biologist almost for almost 200 years. This thesis summarizes the current knowledge about these extraordinary organisms. The first part deals with the morphology and the life cycle of these algae. They share a unique type of reproduction (conjugation) with the other representatives of the class Zygnematophyceae. The second part concerns phylogeny of this genus. Several morphologically distinct species have been revealed with the aid of molecular phylogenetic methods to belong to the genus Micrasterias. A polyphasic evaluation of three species complexes within this genus also revealed an extensive hidden diversity. The last chapters summarize the knowledge about the influence of hidden diversity and accelerated morphological evolution on our understanding of diversity and biogeography of these organisms.
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Cryptic and pseudocryptic diversity of conjugating green algae (Zygnematophyceae)
Kupčíková, Eva ; Šťastný, Jan (advisor) ; Škaloud, Pavel (referee)
This bachelor thesis summarizes the most commonly used species concepts in the class Zygnematophyceae. This group of algae and the molecular markers used in the zygnematophytes' molecular phylogeny will be presented in this thesis. Zygnematophytes have unicellular or multicellular forms and they generally occur in freshwater habitats. Desmids are useful as indicators of water quality and they are also used for scoring of conservation value. Therefore it is important to have the species well defined. The confusion in defining of desmid species was caused by often very variable morphology. Some authors had different opinions on the classifying of desmid species and theirs subunits. The combination of molecular phylogeny, electron microscopy and geometric morphometrics was used in revealing of (pseudo)cryptic species in the genera Micrasterias or Xanthidium. The geometic morphometrics was helpful for finding of important details for distinguishing of particular pseudocryptic species. Key words: cryptic and pseudocryptic diversity, conjugation, desmids, Micrasterias, Euastrum, Xanthidium, molecular phylogeny, taxonomy, geometric morphometrics, biogeography, green algae
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Taxonomy, ecology and biogeography of aquatic and limno-terrestrial diatoms (Bacillariophyta) in the Maritime Antartic Region
Kopalová, Kateřina ; Nedbalová, Linda (advisor) ; Sabbe, Koen (referee) ; Jüttner, Ingrid (referee)
Diatoms (Bacillariophyta) are one of the most diverse algal groups in the Antarctic Region and play a dominant role in almost all freshwater and terrestrial ecosystems. Despite this overall occurrence, little is known about the diversity, ecology and biogeography of this group in the Maritime Antarctic Region. The main objective of this thesis is therefore to define the taxonomical, ecological and biogeographical characterisation of aquatic, semi- aquatic and moss-inhabiting diatom communities from two islands in the Maritime Antarctic Region: James Ross Island and Livingston Island, located on opposite sides of the Antarctic Peninsula. In this study, a total of 250 samples from three different habitat types (lakes, streams & seepage areas and mosses) from Byers Peninsula (Livingston Island) and Ulu Peninsula (James Ross Island) have been analysed. Using light and scanning electron microscopy, a rather diverse diatom flora composed of 178 taxa, belonging to 43 genera has been identified. Although even until recently, it was generally accepted that the Antarctic diatom flora was mostly composed of cosmopolitan taxa, several new species could be described as a new for science during this PhD study (a reflection of this work is presented in chapters 2 & 3 and in Appendices). Habitat type and...
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Unveiling hidden species diversity in desmids (Desmidiales, Viridiplantae)
Šťastný, Jan ; Neustupa, Jiří (advisor) ; F.M. Coesel, Peter (referee) ; Kaštovský, Jan (referee)
The delineation of desmid species was traditionally based on purely morphological features. However, a frequent misinterpretation of morphological variability in desmids has led in the past to extensive taxonomical confusion within this important group of green algae which complicates the interpretation of their biodiversity in freshwater ecology, biogeography and biomonitoring. Consequently, I focused in this thesis predominantly on a previously neglected issue, the application of polyphasic approaches in the species-level taxonomy of desmids. In the most studies, a combination of both traditional morphological and modern molecular phylogenetic and geometric morphometric methods has been used to evaluate the taxonomy of selected desmid species, particularly representatives of the morphologically complex genera Micrasterias and Xanthidium. In two papers, I used the combination of traditional morphological and autecological data to clear up the taxonomy of several morphologically less prominent desmid taxa. Generally, the results of the thesis demonstrated that the way we recently see the diversity and distribution of desmids should be thoroughly changed. The real species diversity is mostly distinctly finer than that estimated by classical morphological taxonomy, often corresponds to varieties of...
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Phylogenetic, morphological and ecological context of microevolution in pennate diatoms
Veselá, Jana ; Neustupa, Jiří (advisor) ; Řeháková, Klára (referee) ; Vanormelingen, Pieter (referee)
Visual assessment of discontinuities in the morphological features of diatom cells has been widely used in the discovery and delimitation of diatom species. However, a multidisciplinary approach to species-level taxonomy has revealed hidden diversity within the traditional diatom morphospecies. Consequently, this work examined both the natural and clonal populations of diatoms by diverse traditional and modern approaches, in order to assess the diversity, ecology, and distribution of diatom species. Although a detailed investigation of natural diatom samples was confounded by uncertain morphological boundaries between the traditional diatom species, it recognized that the diversity was relatively high; even one new diatom species was described using the morphological species concept. The multivariate statistical analyses showed that the variation of natural communities of traditional diatom morphospecies reflected differences in the local environmental conditions, as well as microhabitat heterogenity within a region. Since each diatom morphospecies is most likely a complex of sibling species, the two model traditional morphospecies were investigated, in order to assess morphological variation, genetic diversity, and/or the reproductive compatibility of monoclonal cultures. Even though isolated...
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Biogeography, diversity and substrate specificity of aeroterrestrial green algal genus Klebsormidium (Streptophyta)
Ryšánek, David ; Škaloud, Pavel (advisor) ; Mareš, Jan (referee)
Filamentous aeroterestrial green algae genus Klebsormidium occurs in a very wide range of freshwater and terrestrial habitats. Recent results of molecular investigations led to the finding that the diversity within this genus is far greater than expected on the basis of the morphological features, and that the traditional phenotypic species concept is insufficient. I tried to differentiate phylogenetic lineages within the genus Klebsormidium by thein different biogeographical distribution and environmental preferences. Since no study dealing with the biogeographic pattern of aeroterrestrial algae was so far undertaken, another aim of this work was to test validity of the protist ubiquity model in aeroterrestrial habitats. I studied this issues based on the chloroplast rbcL molecular marker. Based on the obtained data I found that the geographic definition of particular Klebsormidium lineages turns out to be unusable because of the cosmopolitan occurrence of almost all genotypes. However, the data obtained from the substrate specificity study shows that clear ecological preferences exist within the genus Klebsormidium and could be simply used to define different lineages within the genus.
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Biogeografie zázvorovitých z podčeledi Alpinioideae
Hlavatá, Kristýna ; Fér, Tomáš (advisor) ; Záveská, Eliška (referee)
This work aims to summarise the recent knowledge of the distribution of the subfamily Alpinioideae and suggest the possible patterns of distribution and dispersal for individual genera, particularly for South-East Asia, where the majority of genera is found. Alpinioideae is a quite recently established and unresolved group and some of its genera are polyphyletic. The main part of the subfamily is distributed throughout South-East Asia to Australia and Oceania, two genera (Aframomum and Renealmia) are found in Africa and the genus Renealmia has undergone long-distance dispersal to South America. Three genera (Leptosolena, Paramomum and Siamanthus) are monotypic endemics. Alpinioideae is further divided into the tribes Alpinieae and Riedelieae.
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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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