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Early embryonal development and morphogenesis of selected organ systems of the rediae and cercariae of Fascioloides magna.
Pankrác, Jan ; Kašný, Martin (advisor) ; Macůrková, Marie (referee)
Fascioloides magna (giant liver fluke) is a digenetic trematode with two-host life cycle and high veterinary importancy. Typical definitive host is a deer (Cervidae), but many other species from different families can be accidentally infected, for example sheep, goat or cattle. Very important role in the life cycle of F. magna has the first host - fresh water snail of the family Lymnaeidae. Three different life stages of F. magna, two of them with ability of reproduction - sporocysts and rediae develop in the body of snail. The third stage - cercaria is produced by rediae. Cercariae are able to escape from the snail, encyst and become infective for the definitive host. Since the second half of the 19th century many researchers studied the development of particular stages in the first intermediate host, but many characteristics of this process are still not fully understood. This thesis should reveal some of unanswered questions concerning to the reproduction and ontogenetic development of trematodes, which is presented on the examples of three organ systems - muscles, nerves and excretory system of rediae and cercariae of F. magna.
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Study on dynamics of spinning apparatus of some wolf spiders (Araneae: Lycosidae) during their life cycle
Dolejš, Petr
Current knowledge of the spinning apparatus comes namely from studies on orb web spiders and their relatives, whereas that of wolf spiders were more or less neglected. Therefore, developmental changes of the spinning apparatus of four wolf spiders were studied throughout their life cycles. Each of these lycosids possesses stenochronous life cycle with similar number of instars (7-10) but of different length (1-3 years). There is only one period of reproduction in spring/summer in all four species. Sperms are being formed just after the final moult; diplotene in some species is peculiar. The courtship behaviour reflects the microhabitat occupied by the concrete spider species; the copulations are species specific. Ontogeny of the spinning apparatus of developing spiderlings was observed: The spinning apparatus initiate its function in the first instar. Secondary ampullate, all piriform and all but four aciniform glands are tartipore-accommodated; they do not moult in situ. The tartipores, vestigial structures corresponding to spigots of the previous instar, appear on the spinning field starting with the second instar. Tartipore-accommodated glands play roles also during proecdysis and their evolution corresponds with the way how do the spiders secure themselves when moulting. Hence, the not yet...
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Study on dynamics of spinning apparatus of some wolf spiders (Araneae: Lycosidae) during their life cycle
Dolejš, Petr ; Smrž, Jaroslav (advisor) ; Žďárek, Jan (referee) ; Hajer, Jaromír (referee)
Current knowledge of the spinning apparatus comes namely from studies on orb web spiders and their relatives, whereas that of wolf spiders were more or less neglected. Therefore, developmental changes of the spinning apparatus of four wolf spiders were studied throughout their life cycles. Each of these lycosids possesses stenochronous life cycle with similar number of instars (7-10) but of different length (1-3 years). There is only one period of reproduction in spring/summer in all four species. Sperms are being formed just after the final moult; diplotene in some species is peculiar. The courtship behaviour reflects the microhabitat occupied by the concrete spider species; the copulations are species specific. Ontogeny of the spinning apparatus of developing spiderlings was observed: The spinning apparatus initiate its function in the first instar. Secondary ampullate, all piriform and all but four aciniform glands are tartipore-accommodated; they do not moult in situ. The tartipores, vestigial structures corresponding to spigots of the previous instar, appear on the spinning field starting with the second instar. Tartipore-accommodated glands play roles also during proecdysis and their evolution corresponds with the way how do the spiders secure themselves when moulting. Hence, the not yet...
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Ecological traits of vertebrates along elevations
Schovánková, Hana ; Hořák, David (advisor) ; Kubička, Lukáš (referee)
Animals that live in different altitudes are exposed to different environmental conditions. Among others, ambient temperature, precipitation and availability of resources change along an elevational gradient. An adaptation of vertebrates to these conditions causes that in populations or species that live in higher altitudes individual ecological traits evolves to a different degree than in those that live in lower altitudes. Studies suggest that vertebrates that live in higher altitudes usually have shorter active and breeding season, reach larger body size and weight, have slower growth, have smaller clutches or litters, mature at later age and live longer. However, almost in all traits we can find opposite trends. In all vertebrate groups similar changes in traits occur. However, some traits aren`t explored in all groups, for example grow of birds and mammals. Powered by TCPDF (www.tcpdf.org)
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Physiological and hormonal mechanisms influencing ejaculate quality in birds
Mojžišová, Kateřina ; Tomášek, Oldřich (advisor) ; Svobodová, Jana (referee)
Sexual selection is an important mechanism of evolution. In addition to precopulatory sexual selection, arising when males compete for female partners, there is also postcopulatory sexual selection (sperm competition), when females copulate with more males. Even though most avian species are socially monogamous, most of them are also partially promiscuous. In such species, sperm competition is an important factor increasing variability in reproductive success between males. Male's success in sperm competition is primarily determined by sperm concentration, total sperm count and morphology and motility of spermatozoa. My bachelor thesis summarizes knowledge about the hormonal a physiological mechanisms that influence semen quality. This is especially the effect of sex and other hormones, physiological and oxidative stress, environmental conditions, antioxidant mechanism and composition of sperm cell membrane. Besides evaluating their influence on ejaculate quality on intraspecific level, I also describe their differences between avian species with respect to the differences of sperm competition.
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Impact of river system structure on the genetic diversity of reed populations
Fuxová, Gabriela ; Fér, Tomáš (advisor) ; Kubátová, Barbora (referee)
Many plant species are closely related to river biotopes or to biotopes influenced by rivers. River systems create important linear corridors in ecosystems and directly or non-directly influence spatial spread of species in these environments. This offer many questions about species spread in this system. We can answer these questions by using molecular methods. Using 10 microsatellite (SSRs) primers, 202 individuals of Phragmites australis from 60 populations were analysed. Those analyses allowed reveal kinship of individuals, obtain information about spatial spread of populations and about spreading of common reed. Phragmites australis creates both - monoclonal and polyclonal - populations. Dependence of rate of clonality on environment was revealed. Populations from river banks are more monoclonal, populations from pond shores are more polyclonal. Populations are isolated. The highest percentage of variability was explained on among-population level. This is common for anemochoric species. Communication between populations is present, more on shorter distances. Evidence for vegetative spread was found on short distance. Generative spread is much more common. Long-distance spreading is mediated by generative diaspores - seeds. This spreading includes within-river spread, among-river spread and spreading...
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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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Orangutans breeding and factors affecting their reproduction in captivity and in the wild
Kalkušová, Olga ; Kubík, Štěpán (advisor) ; Burešová, Eva (referee)
Information concerning orangutans living in the wild and the issue of their breeding has been summarized within the framework of this thesis. Orangutans in their natural habitats in tropical rainforests of Sumatra and Borneo are not subjected to the same influences as those bred in captivity. Their reproduction thus differs in certain aspects. Reproduction of orangutans in the wild is strongly influenced by their solitary way of life. Females are accompanied only by their young or eventually by other females and according to the studies they seek contact with males only in their period of rut. The contact is then limited to a period of time needed for copulation. One exception to this behaviour may be couples with juvenile males. After birth, the female looks after the young male for up to 8 years, having no rut during this period. The cycle of females living in the wild also shows dependency on the availability of food supply. Negative energy balance during which the cycle stops has been observed during periods of food scarcity. In the following period with abundance of food, the cycle is renewed again. The cycle renewal also occurs in cases when the female loses her young. As a consequence of these reproductive limitations females may give birth to 4 young at maximum in their life.
Guidelines have been drawn up for breeding in zoos which regulate the conditions and suitability of the exhibits so that they meet the orangutans needs. Their natural mental and physical activity is related to their health and natural behaviour. However, despite all efforts the zoos cannot provide the same conditions to the orangutans as those they would have in the wild. The forced increased socialization and contact with other individuals held in captivity may bring stress, stereotype behaviour and associated health problems which are rather frequent with orangutans bred in captivity.
According to the records in the pedigree books, the age of first reproduction and the interval between births were shorter in case of females kept in captivity. Even the keeping of males and females in one exhibit increases the probability of copulation and becoming pregnant. These changes also entail certain risks according to the studies. Breeding in captivity embodies higher mortality rate of young and adult animals. This is probably caused by young age of females at the birth and short intervals between births which are often shorter than 4 years. Females born in captivity also lack experience which they gain in the wild by learning and observing and are not able to take care of their young or refuse it later. Even females that got pregnant between the age of 11 and 14 have been described. However, such pregnancy poses a great risk for females and they die soon after birth or live much shorter. Young orangutans born in captivity were often taken away from their mothers. It is not very suitable on the one side, but on the other side, after having their young taken away from them, the females started a new, full-fledged cycle in a few weeks and could become pregnant again. However, as direct care of the young by humans has a negative effect, the young are often given back to their mothers which is successful in many cases.
Orangutans have been studied for more than 40 years and a lot of things concerning their breeding in captivity have changed during this time. Zoological gardens are trying to provide the orangutans as natural conditions as possible. It is necessary for the exhibits and the enrichment to provide enough physical and mental activities to the orangutans. Despite these efforts, the limited space and the related contacts between individuals may bring stressful situations. These are then manifested in the behaviour and health of the orangutans.
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Biology, seed characteristics and growth establishment of comfrey (\kur{Symphytum officinale }L.)
KOVÁŘOVÁ, Jaroslava
The thesis titled "Biology, seed characteristics and growth establishment of common comfrey (Symphytum officinale L.)" dealt with the evaluation methods of reproduction comfrey and evaluation of the impact of environmental conditions to the grow of comfrey. Further it dealt with germination tests and their statistical evaluation while respecting the specific work with seeds. They were evaluated seed characteristics, which are reflected in the growth of these plants arising both in soil and in a laboratory environment. Literary part gave information about biology, characteristics, morphology, prevention and regulation of comfrey even more its cultivation, nutrition of the grassland and seed characteristics, germination and dormancy. In the final section of work was monitored coverage, botanical images, representation of herbaceous species growing near comfrey. The study also discussed vernalization, size of comfrey leaves, growth and development depending on the content of nutrients (soil fertility) and water in the soil and on the number of cuts to its growth. There were designed a suitable ways of reproduction and growing of comfrey.
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