|
|
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.
|
|
|
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...
|
|
|
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,...
|
|
|
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.
|
|
|
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.
|
|
|
Průzkum sortimentu perspektivních druhů skalniček
Ambrožová, Klára
This Bachelor's thesis was elaborated on the Department of Breeding and Propagation of Horticultural Plants on the Faculty of Horticulture of Mendel University in Brno. The thesis is focused on the characteristic description of alpine plants including growing, geographic expansion, cultivation and reproduction. The main attention is devoted to an overview 110 of promising species and their cultivars that are the most cultivated in the Czech Republic. The thesis includes own experience with the cultivation and sale of alpine plants in the company Kinský Žďár, a. s., and Květiny Veselská. The basic characteristics are, for clarity of species sorted in tables in the annexes, including important varieties. The annex includes 61 major genera and 110 species of plants, including their characteristics.
|
|
|
Reproduction of Hawaiian red shrimp \kur{Halocaridina rubra}
HOMOLKA, Václav
Hawaiian red shrimp - Halocaridina rubra (order Decapoda; family Atyidae) is an endemic species originated from Hawaii Islands. It is adapted to a specific environment of underground systems and anchialine pools. Halocaridina rubra has a great potential for aquarium shrimps breeders as well as for researchers. The aim of this work was to: (1) document the reproduction of shrimp Halocaridina rubra and (2) determine the influence of selected chronobiological factors and presence/absence of a shelter for its reproduction. The experiment was realized in the aquarium room and chronobiological laboratory at the department of Biological disciplines at the Faculty of Agriculture, University of South Bohemia in České Budějovice. The experiment took three months (i.e. from 3 rd November 2014 to 3 rd February 2015). This experiment had 4 treatments each with two repetitions: on the light with and without a shelter, in the dark with and without a shelter. Experimental shrimps were put into the aquaria in the breeding groups: 10: 16 (female: male). The frequency of mating was evaluated. Neither the light conditions (12 h (light): 12 h (dark) or permanent dark) nor the presence of shelter had impact on the reproduction of Halocaridina rubra. The reproduction of shrimp Halocaridina rubra was documented. Spermatophore transfer, eggs, four larval stages of zoea type, megalopal stage and two juvenil stages are monitored. Recommendations for breeding have been developed. Anesthesia was tested by using eugenol (clove oil) in shrimps.
|
|
|
Použití vybraných druhů z rodu Lonicera L. v zahradní a krajinářské tvorbě
Hrabík, Pavel
This bachelor work focuses on the uses of genus Lonicera L. in garden and landscape formation. The thesis is divided into two parts. The first section contains a description of the genus and evaluation of information sources. The second part is more extensive and consists of three fractional parts. Evaluation of selected species of the genus Lonicera L. terms of important characters, ecological requirements and use. There is also a section dealing with methods of propagation representatives of this genus. And the last part is the evaluation of the offer of garden nurseries in the Czech Republic.
|
|
|
Analýza možnosti ovlivnění reprodukčních a produkčních ukazatelů prasniček konjugovanou kyselinou linolovou
Hadaš, Zdeněk
The disertation analyses the possibility of influencing reproduction and production paramatres of gilts and sows with the addition of 2 % conjugated linoleic acid in feed mixtures in operating conditions of a production pig farm. The evaluation of mean achieved daily growth for the time from birth to the end of the test confirmed higher values for gilts in the experimental group. Within other parametres of efficiency of gilts, ie. the lean meat rate, backfat thickness and the depth of MLLT muscle, no significant influence of CLA on their phenotypic manifestation was found. On the basis of gained results it can be concluded, that the supplementation of CLA decreases the mean age of gilts at the time of their first serving. At the same time, the age of first farrowing was lower in the experimental group. Evaluation of reproductive performance parametres revealed a tendency of reaching better results in the experimental group, however without statistically significant differences. In the another part of this study, the sows of the experimental group had provably longer gravidity, the birth weight of piglets was not affected. Results of the experiment show significantly higher number of reared piglets in the experimental group of sows and related level of piglet losses from birth to weaning. Growth ability of piglets from birth to weaning do not show any significant effect. The aim was also to evaluate whether CLA administered to sows during lactation influences an inclusion to next reproductive cycle. Shorter interval of estrus onset was found in the group of sows with compound feed enriched with conjugated linoleic acid. Although the results of conception of sows after weaning pigltes speaks in favour of the experimental group, no significant difference was proved.
|
|
|
Biologie rozmnožování u raků
NIKSIRAT HASHJIN, Hamid
The ultrastructure of spermatozoa from six crayfish species were described. The acrosome complex and nucleus are located at the anterior and posterior of the spermatozoon, respectively. The acrosome complex organelle is divided into two main parts: the main body of the acrosome that is a dense inverted cup-shaped structure and organized into three layers of differing electron densities and extended parallel filaments, and the sub-acrosome zone occupying the central part of the acrosome complex, which is divided into two electron dense areas. The spermatozoon of Orconectes limosus is described for the first time. In addition, an acrosome spike in the spermatozoon of Procambarus clarkii is described. Despite a well conserved general structure and similarity of pattern among these spermatozoa, differences in the dimensions of the acrosome within the studied species may be useful to help distinguish the different crayfish. The ultrastructure of the spermatozoon and spermatophore wall of the narrow clawed crayfish Astacus leptodactylus during three stages including freshly ejaculated, post-mating, and after release of the spermatozoon were described and compared. The crayfish spermatophore consists of a sperm mass enveloped by a three layered spermatophore wall. After mating, the thickness of the outer layer of the spermatophore is increased. The matrix in the middle layer of the spermatophore becomes reticulated, and granules inside this layer release their contents. Fibers in the inner layer degrade to small particles. The spermatozoon capsule swells and space between the capsule and the spermatozoon appears. The area of the plasma membrane is increased by wrinkling of the surface and alteration from a single to a multilayered structure at the anterior part of the acrosome. The density of the subacrosome zone increases in the vicinity of the main body of the acrosome. With the onset of fertilization, the layers of the spermatophore are dissolved by female glair glands secretions. The capsule, plasma membrane, and membranous lamellae are eliminated, and bundles of filaments are released. The subacrosome zone loses electron density and retracts. The electron-dense material of the innermost layer of the acrosome is discharged and, together with filaments, forms a filament/droplet structure at the anterior part of the spermatozoon. The most important change is observed in the subacrosome zone, which may play a key role in the fertilization. Also, morphological changes of the spermatozoon after release from the capsule, especially formation of the filament/droplet structure, may contribute to the mechanism of egg-spermatozoon binding in the crayfish.
|
guest ::
