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Systermatics and biogeography of the genus Platyceps with special emphasis on the Middle Eastern species
Velenská, Doubravka ; Šmíd, Jiří (advisor) ; Rehák, Ivan (referee)
The colubrids genus Platyceps has been included in several phylogenetic studies of the family Colubridae, however the phylogenetic relationships between its species still remain unresolved. The major problem is an insufficient coverage of species in genetic analyses. In this study, I analyse 90 specimens of fourteen Platyceps species to shed more light on the evolutionary history of the genus. Some of the species have never been included in such a genetic analysis before. The phylogeny is based on a combination of four mitochondrial (12S rRNA, cytb, COI, ND4) and two nuclear (cmos, NT3) markers. My results confirm the genus as monophyletic and divide it in to three major clades - the Indian clade (P. bholanathi, P. gracilis, P. ladacensis, P. ventromaculatus a P. sp_central_asia), the West Asian clade (P. karelini, P. rogersi, P. saharicus a P. rhodorachis) and the Dispersive clade (P. plinii, P. josephi, P. florulentus, P. taylori, P. najadum, P. collaris, P. elegantissimus, P. manseri, P. sinai, P. variabilis). According to the results, the phylogenetic positions of several species differ considerably compared to previously published studies. The species Platyceps thomasi appears to be just a colour morph variation of Platyceps variabilis. Platyceps variabilis manseri, on the other hand, emerges...
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Phylogeography of the Bunopus geckos (Squamata, Gekkonidae) in the Arabian Peninsula
Pola, Lukáš ; Šmíd, Jiří (advisor) ; Rehák, Ivan (referee)
The Arabian Peninsula represents a bridge between three continents and two major zoogeographic regions, the Palearctic and Afrotropical (Ethiopian). It is well known for its richness and endemicity not only among geckos, but among squamate reptiles in general. Besides impressive endemic species located in the mountains, there are some, widely distributed across the entire Arabian Peninsula (pan-arabian distribution) and in terms of research they remain neglected. Among Arabian geckos, the genus Bunopus are an excellent example, whose systematics and taxonomy are quite problematic, albeit they are distributed across the entire peninsula. In order to answer the question of possible cryptic diversity of these geckos in the Arabian Peninsula, phylogenetic position of more than 80 samples covering the vast part of their distribution range has been reconstructed based on two mitochondrial (12S rRNA and COI) and two nuclear markers (RAG2 and c-mos). Haplotype networks were reconstructed from nuclear markers in order to show genealogical relationships. Results of the phylogenetic analyses presented herein show that cryptic diversity in the Arabian Peninsula is smaller in comparison to the one that was uncovered in the Iranian Plateau. Almost entire Arabian Peninsula is inhabited by two lineages only, which...
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Body surfaces of reptiles as projection screens of evolution
Abramjan, Andran ; Frynta, Daniel (advisor) ; Rehák, Ivan (referee) ; Šulc, Michal (referee)
The PhD thesis deals mainly with the coloration (and also scalation) of selected reptile species and explores evolutionary or ecological contexts indicated by these traits. The main topics can be roughly divided into two groups: 'antipredation signals' and 'effects of parthenogenesis'. The dominant method used in most studies is visual modelling. The work consists of the following case studies. 1) Blue-tongue skinks use their conspicuous blue tongues to threaten potential predators. We found that the tongue has a relatively high UV reflectance, a typical feature of intraspecific communication in lizards. Using visual models, we investigated how the blue tongue is perceived by the conspecifics and predators (birds of prey). In both visual models, the UV-blue tongue appears more conspicuous against the natural background than a pink tongue. In addition, in the conspecifics model, its hue partially overlaps with hues of UV-blue spots, which are sexually selected traits in various species of lizards. Thus, the UV-blue tongue seems to contribute to the effectiveness of the deimatic display and its possible role in intraspecific communication cannot be ruled out either. 2) We detected UV reflectance in non-pigmented areas of the skin in the Leopard gecko (Eublepharis macularius). These form white patches...
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Multi-component signalling in turtles and squamate reptiles
Brejcha, Jindřich ; Kleisner, Karel (advisor) ; Rehák, Ivan (referee) ; Carazo, Pau (referee)
Multicomponent signals are complex stimuli directed to receptors of only single modality. Colourful ornaments of animals are multicomponent signals. In this thesis I present results of studies on the origin of coloration in turtles and squamate reptiles together with notes on relativistic view of the functionality of animal coloration. The results show that turtle coloration, which have been studied only marginally until now, is shaped by sexual selection. It is shown that turtles share mechanisms of coloration by vertical organization of different pigment cell types together with squamate reptiles. Turtles also produce colour by organization of collagen fibres which share trait with birds and mammals. Mechanisms of body coloration differ dramatically between closely related turtle species studied even though the individual constituting components are shared among these species. On the example of polymorphic lizards, it is shown that qualitative categorical difference between groups of individuals of the same population are maintained based on quantitative changes in pigment contents regulated by ancient loci shared by different species. The turtles and reptiles are valuable source of our knowledge on the evolution of multicomponent visual signalling due to their intriguing composition of skin....
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Social interactions and morphometric analysis of populations of Blue-Tongued Skink (Tiliqua gigas)
Jachnická, Kristýna ; Frynta, Daniel (advisor) ; Rehák, Ivan (referee)
A Blue-tongued skink ( Tiliqua gigas) is a rare exotic species which is very popular between breeders. Nevertheless, the social structure of this charismatic skink remains almost unknown. Because of its high aggressive- ness and difficulties connected with study in its natural habitat, experiments based on the odor discrimination looks like a good alternative for its bet- ter understanding. Our results revealed that the reaction on the odor is generally poor and is very individual. We observed the highest response of interest on odors produced throught dorsal parts of skin. The reaction on conspecific's odor did not lead to escape behavior. Behavioral analysis was complemented by morphological analysis of heads in T. gigas and T.scincoides. These species are divided into separate subspecies, which are formed by geographically distinct populations. We wondered whether it is possible to separate these populations by geometric morphometrics and whether this separation is consistent with phylogenetic studies. We found out that if the populations are united in bigger groups based on their congeniality they seem to be distinct according to the head shape. Our results also revealed the monomorphy in head shape. Unfortu- nately, it is very difficult to distinguish between sexes due to the absence of sexual dimorphism....
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ANALYSIS OF AMPNIBIAN NADITAT PREFERENCES IN THE NORTH - EAST PART OF THE TŘEBÍČ DISTRICT
Jeřábková, Lenka ; Švátora, Miroslav (advisor) ; Rehák, Ivan (referee)
8 ABSTRACT In the north-east part of the Třebíč district 108 water sites were repeatedly monitored to analyze breeding of amphibians where its 11 species were proven by this research. Bombina bombina, Bufo bufo, Bufo viridis, Hyla arborea, Pelobates fuscus were proven in line with previous studies. However, species Triturus cristatus, Triturus vulgaris, Rana temporaria, Rana dalmatina, Rana esculenta synklepton were monitored in the region for the first time ever. Distinctly high values of the species presence were reached by BufBuf (60,2 %), RanEscSyn (78,7 %) and HylArb (48,1 %). In contrast, species TriCri, TriVul, BufVir, RanArv, RanDal were found in the region with low frequency. There were found positive correlations in the proportion of littoral, natant and submerse vegetation and in the transparency of the water column and in contrast negative correlations were found in the extent of urban areas and with the number of amphibians breeding in the water site. The Redundancy analysis (RDA) helped to discover statistically significant influence of the environmental variables (proportion of littoral vegetation, transparency, water site total surface and lastly number of other water sites within the range of 500 metres) on the presence of amphibians on the water sites. Consequently, "ideal breeding sites"...
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