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Morphometric disparity in European lineages of gobies (Gobiidae)
Bílá, Kristina Beatrix ; Vukićová, Jasna (advisor) ; Frýdlová, Petra (referee)
Gobies (Actinopterygii: Gobiiformes), are a remarkable group of fishes, not only because they are the most species-rich order of bony fishes (Teleostei), but also due to their extraordinary ability to colonize different types of environments. As a consequence, they evolved a variety of morphological shapes. The aim of this work was to reveal whether the European evolutionary lineages of gobies evolved ecomorphs through repeated colonisation of the same types of microhabitats, i.e. whether morphology (body shape) is influenced by niche, and what role convergent evolution plays in adaptation to different types of environments. For this purpose i made quantification and comparison of body shape using the methods of geometric morphometry. The results of this work showed that convergent evolution has occurred in four out of the six ecological groups of studied gobies, i.e., that their shape is influenced by the environment they inhabit and their way of life, regardless of lineage affiliation and phylogenetic relationships. Convergent evolution has been revealed in hyperbenthic, nektonic, marine epibenthic and freshwater epibenthic species. In contrast, convergent evolution has not been proven in euryhaline epibenthic species, nor in cryptobenthic species of gobies. Key words: geometric morphometry,...
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Perception of the human disturbance by ungulates in the wild and in the captivity
Šťastná, Tereza ; Komárková, Martina (advisor) ; Frýdlová, Petra (referee)
The relationship between ungulates and humans has been evolving ever since the first predator's interaction with the prey, leading to the current domestication. The behavior of ungulates differs based on the human disturbance. The goal of this thesis was to compare the reactivity to humans of selected species in nature vs. in captivity and determine its correlation, inter or intraspecific. The thesis indicates reactivity to humans of specific species of ungulates (donkeys, horses, reindeers and goats). Following reactions were chosen for comparison: vigilance, alert distance, flight and avoidance distance. There are several acting factors like previous experience with humans, habituation, group size or season. With group size, the vigilance decreased, which was proven with donkeys, reindeers and goats. The behavior differed based on the season by resources availability, offspring's presence in herd (higher vigilance) or rut (lower vigilance). In captivity, there were less human contact avoidance, while the experimenter was known. Based on researches, ungulates tend to avoid humans more in nature, than in captivity. Sources claim, that among chosen ungulates, the most vigilant in both nature and captivity are reindeers. Further researches could later consider the human perception according to the...
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Comparative analysis of sexual and agonistic behaviour in eyelid geckos (Eublepharidae)
Rauner, Petr ; Kratochvíl, Lukáš (advisor) ; Frýdlová, Petra (referee)
Sexual selection is one of main selective pressure affecting body size, and subsequently leads to the evolution of sexual size dimorphism (SSD). The eyelid geckoes, family Eublepharidae, are a monophyletic group with considerable variability in SSD, including both male-larger and female-larger species. In general, it was supposed that eyelid geckos are highly variable in presence of male combats and in complexity of male pre-copulatory behaviour, and that this variability in this conspicuous male behaviour may lead to differences in SSD. The aim of this study was to reveal relationships between the direction of SSD and presence/absence of tail vibration during precopulatory phase and male combat behaviour. Using behavioural testing, it was revealed that male combats are present in all tested species, even in species, where the absence of such behaviour was supposed so far. In several species, the strong effect of seasonality to male aggression was observed, which may play a role in the evolution of SSD. The evolutionary changes in the presence/absence of tail vibration during precopulatory phase were independent on changes in the direction of SSD, the presence of tail vibration seems to be ancestral state for these lizards. During the evolution of this group, the tail vibrations disappeared four...
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Factors influencing flight-initiation distance in reptiles and the comparison with endotherm vertebrates
Fictumová, Tereza ; Frýdlová, Petra (advisor) ; Sedláček, Ondřej (referee)
The fleeing behaviour is one of the most common antipredatory strategy. It is intensively studied in many groups of animals. The flight-initiation distance (FID) is used for quantification of fleeing behaviour. The FID represents the distance between a prey and an approaching predator in which the prey starts fleeing. The FID is also used for quantifying of preys fear. The factors influencing FID in reptiles are: temperature, habitat, refuge availability, foraging strategies, predator behaviour etc. I discovered some factors which are different for mammals and birds. The most important difference is the ectothermy in reptiles vs. the endothermy in mammals and birds. Another difference is parental care, alarm calls and grouping. The factors as an influence of predator, refuge availability or type of habitat seems to have very similar or the same impact on FID for both groups.
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Hormonal control of sexual size dimorphism in vertebrates
Tureček, Adam ; Kratochvíl, Lukáš (advisor) ; Frýdlová, Petra (referee)
Males and females of one species share the majority of the genome, often also the joint niche, but their phenotype is usually very different. The biggest difference between the sexes is the achievement of different sizes that can be controlled dimorphic secretion of hormones. Although many researches have been conducted on this topic, we still lack the knowledge that at least in vertebrates exists in this respect a single, common proximate mechanism or whether different types or lines vary considerably in hormonal control of dimorphism in body size. Growth is influenced by a variety of hormones that can interact - for example, growth hormone, somatomedins, thyroid hormones and steroid hormones. However, experimental studies have suggested that influence levels of sex steroid hormones can cause a change in sexual dimorphism in size. My work focuses on summarizing knowledge about hormonal influence dimorphic growth in vertebrates and analyse the methodology used. Powered by TCPDF (www.tcpdf.org)
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Evolution of prey-catching behaviour in poikilothermic vertebrates and its relationship with predator's visual perception
Košinárová, Lucie ; Frýdlová, Petra (advisor) ; Robovská, Pavla (referee)
Both the topics of prey-catching mechanism and visual perception are closely connected, affecting each other in many complex situations. The main subjects of this thesis were amphibians and reptiles and the many effects that impact their hunting abilities. We studied their hunting patterns in a few species of frogs and the leopard gecko (Eublepharis macularius) in an arena. We did not find any universal hunting pattern for neither of those groups, moreover even the quantity of individual sequences differed among them. However, hunting in nature is often engaged in habitats that are far from the flat calm arena. Often the animals have to adapt to different conditions, for example an unsteady surface underneath them. In such conditions they need to compensate for the passive movement with their heads and eyes to stabilize the image on their retina. The ability to compensate while hunting in frogs is affecting their behaviour and the success rate of their prey-catching. Another aspect that is influencing frog's hunting efficiency are their protrusible tongues that are commonly divided into three categories: mechanical, inertial and hydrostatic. The last goal of this thesis was looking for the evolution of this trait in frog's phylogenesis and their different effects on hunting movements.
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Self-assessment and mutual-assessment ability in squamate reptiles
Čekal, Jakub ; Frýdlová, Petra (advisor) ; Kubička, Lukáš (referee)
Agonistic interactions throughout the animal kingdom can inflict various costs upon involved animals (decreased fitness, higher risk of predation etc.). To prevent such losses, many species have developed different morphological and behavioural adaptations to display their fighting ability. These adaptations allow animals better assessment of different costs and benefits associated with fighting. Assessment can be divided into two main categories based on the amount of information, that opponents take into account. Self-assessment assumes that rivals consider only their competitive ability and the potential benefits of winning a fight. During mutual-assessment competitors are also capable of considering possible differences in their apabilities and either escalate the fight or back down. My thesis is literary research of this topic in squamate reptiles. The assessment was characterized in several families of Squamata. Additionally, it evaluates the most important traits, that determine a potential winner and introduces different behavioural models of assessment. Used literature suggests that the most reliable predictor of fighting success within these families is the body size, and that mutual-assessment seems to be more prevalent. Keywords: assessment, RHP, aggression, agonistic interactions,...
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Ecological Effects of Climate Change on Snakes
Veverková, Barbora ; Sedláček, Ondřej (advisor) ; Frýdlová, Petra (referee)
Climate change is currently one of the biggest threats that animal species must face. Increasing temperatures cause declines in wildlife populations all around the world. Ectothermic animals might be amongst the most threatened organisms by climate change due to their ecology that makes them dependent on ambient temperature. As ectotherms, snakes will most likely need to adapt to new climatic conditions, or they become extinct. To escape raising temperatures and decreasing precipitation, snakes might shift their ranges and move into more suitable areas. However, snakes have a low dispersal ability, which might lead to range reduction and in some populations even extinction. Climatic changes might affect health and behaviour of snake species as well. Increased temperatures can alter incubation period and embryonic development. Alterations in embryonic development and reduction of incubation period can cause different kinds of malformations, especially in oviparous snakes. These malformations can negatively impact fitness, depending on their severity. Some snake species might also benefit from climate change. Elevated temperatures allow snakes to be more active and, in some cases, even shorten hibernation duration. Snakes are also able to better escape predators in high temperatures than in low...
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Evaluation of hybridization effect on fitness of eyelid geckos (Eublepharis, Gekkota) by performance tests
Kohoutová, Tereza ; Frýdlová, Petra (advisor) ; Sedláček, František (referee)
An interspecies hybridization is usually viewed from two sides - either as mistakes in a reproduction resulting in decrease of a hybrids fitness (e. g. loss or decrease of viability and fertility) or as a mechanism helping animals adaptively respond to environmental changes resulting in higher fitness. Fitness is usually represented as a set of correlates. One of the correlates is an organism performance which is represented by a set of maximal values from measured physical activities. This thesis focuses on the evaluation of the endurance and the bite force for gecko species E. macularius and E. angramayniu, their interspecies hybrids and intraspecies hybrids to determine their performance. The results show differences in the bite force among each of the tested groups. E. macularius has the lowest bite force, while the highest bite force was measured in E. angramayniu. The bite force of interspecies hybrids is intermediate in comparison to the parent species. Nevertheless, intraspecies hybrids of large form and white form of E. macularius exceeds their parents in measured bite force. The variability in bite force suggests a positive effect of hybridization on fitness. The bite force differences between the large form and the white form of E. macularius support the hypothesis that there exist more...
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