National Repository of Grey Literature 9 records found  Search took 0.01 seconds. 
Microhabitat preferences for overwintering water bugs
ČIHÁK, Petr
This diploma thesis deals with overwintering of water bugs. The goal of the thesis is to experimentally find out what microhabitats do these water bugs prefer for overwintering. The experiment took place in the greenhouse in the educational garden of PF JU in České Budějovice (48° 58'32.182 "N, 14° 26'54.218" E) from the beginning of November 2017 to the beginning of March 2018. Terrestrial and water microhabitats were created in the greenhouse. They served as a place for potential overwintering of the water bugs. Defined numbers of individuals of given species were put into the center of the greenhouse in boxes with small amount of water. The source of the water bugs were surrounding ponds and a pool in the educational garden. At the end of the experiment, all microhabitats and their surroundings were closely looked through. The found individuals (both alive and dead) were counted and put into sample containers filled with concentrated alcohol. The results are following. Notonectidae prefer mainly water microhabitats, mainly when there are rotting leaves. Corixidae do not prefer any of these microhabitats and presumably they escaped through the little holes in the greenhouse. Nepidae stayed in the original box throughout the experiment. The Ranatra linearis died, whereas Nepa cinerea survived until frosts that caused complete freezing for several following days.
Adaptation for Low Temperature Survival and Taxonomic Diversity of Invertebrates in a Snow Environment.
Babůrek, Jan ; Říhová, Dagmar (advisor) ; Pavlíková, Anežka (referee)
Title: Adaptation for Low Temperature Survival and Taxonomic Diversity of Invertebrates in a Snow Environment. Abstract: This bachelor thesis represents a review of contemporary knowledge concerning cold hardiness and activity in a snow environment in invertebrates. The first part is focused on the influence of cold on the organisms and strategies of survival in cold environments. The following chapter represents a description of substances (e.g. ice nucleating agents, cryoprotectants, antifreeze proteins or water) participating in a level of cold hardiness. Diapause is mentioned as well, as it can influence cold hardiness. Moreover, adaptations to living in cold environment are discussed from an evolutionary point of view with emphasis on the specificity of survival strategies depending on the climate. The final chapter focuses on animal taxa which remain active in a snow environment. Organisms active in the winter environment of temperate climate as well as nival fauna of regions with permanent snow are included. This chapter also contains a list of invertebrate taxa occurring on snow cover with notes to their ecology and phenology. Key words: cold hardiness, cold adaptations, nival fauna, winter survival, invertebrate animals
Activity of Invertebrates in Winter and the Verification of the Selected Invertebrates Capturing Methods During the Winter Season
Babůrek, Jan ; Říhová, Dagmar (advisor) ; Hanel, Lubomír (referee)
This diploma thesis is focused on invertebrates' survival and activity during winter; and on methods of their capture. The first part of the theoretical section describes principles of cold hardiness, strategies of winter survival and activity in snow environment. Furthermore, different methods of invertebrates capturing are presented. The practical part of the thesis is focused on the verification of selected invertebrates capturing methods during winter. The results summarize the differences in the diversity and quantity of animals caught; and provide an overview and characteristics of selected captured taxa. Suggestions for a snow fauna excursion and a practical exercise focused on capturing invertebrates during winter are proposed based on the results of the study. KEYWORDS cold hardiness, winter survival, winter activity, snow fauna, invertebrate animals, catching methods, pitfall traps
Adaptation for Low Temperature Survival and Taxonomic Diversity of Invertebrates in a Snow Environment.
Babůrek, Jan ; Říhová, Dagmar (advisor) ; Pavlíková, Anežka (referee)
Title: Adaptation for Low Temperature Survival and Taxonomic Diversity of Invertebrates in a Snow Environment. Abstract: This bachelor thesis represents a review of contemporary knowledge concerning cold hardiness and activity in a snow environment in invertebrates. The first part is focused on the influence of cold on the organisms and strategies of survival in cold environments. The following chapter represents a description of substances (e.g. ice nucleating agents, cryoprotectants, antifreeze proteins or water) participating in a level of cold hardiness. Diapause is mentioned as well, as it can influence cold hardiness. Moreover, adaptations to living in cold environment are discussed from an evolutionary point of view with emphasis on the specificity of survival strategies depending on the climate. The final chapter focuses on animal taxa which remain active in a snow environment. Organisms active in the winter environment of temperate climate as well as nival fauna of regions with permanent snow are included. This chapter also contains a list of invertebrate taxa occurring on snow cover with notes to their ecology and phenology. Key words: cold hardiness, cold adaptations, nival fauna, winter survival, invertebrate animals
Latitudinal effect on cold tolerance of a firebug Pyrrhocoris apterus
JANDA, Václav
This thesis deals with the relationship between the place of origin and the extend of cold hardiness of fire bug Pyrrhocoris apterus (Linnaeus, 1758). Thirteen populations from twelve European localities were used in the experiment. Linear regressions were used to relate the values of SCP (10th percentile, first quartile, mean and median) of the individual populations to minimum and average winter temperatures of given localities. The relationship between air temperatures and SCP values were significant provided that the data of all populations were used. After the removal of three southern non-diapausing populations this relationship lost its significance.
Cold tolerance of mountain and lowland butterflies
VRBA, Pavel
The thesis deals with ecophysiology of overwintering larvae of two butterfly genera, Colias and Erebia. It focuses on identification of supercooling point, survival of various low temperature regimes and composition of cryoprotective substances. Results are presented in the context of distributional limits of individual species, their habitat requirements and their potential endangerment due to environmental and habitat changes.
Cold adaptation of insects: the role of shock proteins from Hsp family.
ŠTĚTINA, Tomáš
Heat shock proteins (Hsps) form evolutionarily conserved group of proteins that are best known for their unique function in repair of miss folded proteins that would otherwise aggregate in cells during stress conditions. The most extensively studied is the inducible Hsp70. Using 3rd instar larvae of transgene mutant of fruit fly, Drosophila melanogaster that lacks all copies of hsp70 gene, we assessed: 1) whether the absence of this gene is deleterious for larvae in their capacity to survive cold stress; and 2) whether any other gene from Hsps family may compensate for the loss of hsp70. We found that 1) survival of cold stress is not altered in Hsp- larvae when compared to wild type Hsp+ larvae; 2) there is no other gene of Hsps family that would compensate for the loss of hsp70 at the level of transcription. Our ongoing effort is focusing on analysis of cold stress response at the protein level.
Insect cold tolerance and seasonal changes in composition of sterols and tocopherols
URBAN, Tomáš
Presented work focused on researching cold resistance in insects (Pyrrhocoris apterus), especially in qualitative and quantitative composition and seasonal changes in the content of tocopherols and sterols in membranes. Collection of samples, tissue extraction, separation, sample preparation and the final analysis was included. There were detected three different sterols (animal cholesterol, plant sterols: campesterol and sitosterol). Also were detected ?-tocopherol and ?-tocopherol. Volume of cholesterol was in the range of 0.2 to 0.8 mol%, for phytosterols was the range from 1.2 to 15.2 mol%, and for tocopherols was the range from 0.1 to 31.3 mol%. Seasonal fluctuations of sterols and tocopherols were evaluated with a minimum in summer and maximum in winter.
Cold resistance of the water cricket Velia caprai: the influence of acclimation age class and food availability on the supercooling point
NOVOTNÁ, Iveta
Recently, the cold resistance becomes a common topic in scientific articles. If we focus on order Heteroptera, we can find a lot of studies dealing with the cold resistance or with the supercooling point (SCP) and also with the factors that influence them. According to the general rule, the acclimation at low temperatures increases the cold resistance. Therefore, the main goal of this thesis is to find out, whether the acclimation also increases the cold resistance of the water cricket Velia caprai Tamanini, 1947 (Veliidae), with the intention to measure SCP of the water crickets depending on the acclimation temperature and the length of exposure. Due to the high mortality (the 284 individuals remained alive of total 1300) and due to the technical difficulties in measuring of SCP (measured only 36 individuals) it was necessary to modify the original goal of the thesis. The new goal was to test the influence of acclimation (during one month vs. one week) and the influence of different temperatures (0°C, 5°C, 10°C) on SCP of V. caprai. The individuals used for this measurement were collected during the year 2010 and in March 2011. The results of this thesis did not confirm the hypothesis that the acclimation at low temperatures increases the cold resistance. The individuals who were acclimated at a higher temperature have the values of SCP demonstrably lower than the individuals who were acclimated at low temperatures. The individuals who overwinter for the first time have arguably higher cold resistance than the individuals who overwinter for the second time. Probable cause of these results is the fact that the water cricket V. caprai does not start with diapause in the fall but it overwinters in quiescence.

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