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Nutritional biology of synanthropic mites (Acari: Acaridida)
Erban, Tomáš ; Smrž, Jaroslav (advisor) ; Grubhoffer, Libor (referee) ; Šustr, Vladimír (referee)
Ph.D. THESIS TITLE Nutritional Biology of Synanthropic Mites (Acari: Acaridida) ABSTRACT Several attempts to describe the nutritional biology of acaridid mites were undertaken, however full understanding of these processes remains incomplete. The objective of this Ph.D. thesis was to expand our knowledge concerning digestive physiology of stored product and house dust mites and to apply this knowledge to their nutritional biology. The research approach adopted in this Ph.D. thesis includes in vitro characterization of enzymatic activity in whole mite extracts (WME) and spent growth medium extracts (SGME), evaluation of the enzyme activities with respect to the gut physiological pH, enzyme inhibition experiments, in vivo localization of enzyme activities in the mite gut, determination of effects of nutrient or antifeedant additives in experimental diets on mite population growth and determination of the feeding preferences of synanthropic mites as assessed by in vitro and in vivo analyses. The gut contents of twelve species of synanthropic acaridid mites were determined to be within a pH range of 4 to 7 and showed a pH gradient from the anterior to the posterior midgut. The pH in digestive tract of synanthropic acaridid mites corresponds to the activity of proteases, α-glucosidases, α-amylases and...
Digestive enzymes in ants (Hymenoptera: Formicidae) : a short review
Šustr, Vladimír ; Schlick-Steiner, B.C. ; Steiner, F. M.
The literature data on the digestive enzymes present in different taxonomic groups of ants are reviewed and their patterns of occurrence across the various groups are tested. Data are available on 32 digestive enzymes from 62 ant species from 15 tribes belonging to seven subfamilies (Dolichoderinae, Ecitoninae, Formicinae, Myrmicinae, Paraponerinae, Ponerinae, and Pseudomyrmecinae). Leaf-cutter ants (Myrmicinae, higher Attini) are the best-investigated group. Nearly all analysed enzymes were present in all the species investigated, irrespective of taxonomic group. The only significant difference across taxonomic groups concerns enzymes that attack plant structural polysaccharides (cellulases, pectinase, xylanase). These were more frequent in leaf-cutter ants than in other groups. To detect potential additional differences between groups differing in their feeding habits, more comprehensive qualitative data acquisition will be necessary.
Microscopic fungi as food of cave invertebrate animals - a laboratory food preference experiment
Nováková, Alena ; Luptáčik, P. ; Kováč, L. ; Lukešová, Alena ; Šustr, Vladimír
The aim was to improve the methodology of the multi-choice food preference tests as a tool for investigation of feeding preference of cave invertebrates. Fungi and algae isolated from cave sediments of the Domica Cave system (NP Slovak Karst) were offered in cafeteria tests as a food to springtail .i.Folsomia candida./i., mites .i.Pantelozetes cavatica, Scheloribates pallidulus./i., and isopod .i.Mesoniscus graniger. M. graniger./i. preferred some species of algae, all offered fungi were rejected. Mainly algae and .i.Mucor./i. spp. from microscopic fungi are preferred by .i.S. pallidulus./i.. Preference of .i.Mucor./i. spp. was observed by cave mite .i.P. cavatica./i. and cave population of .i.F. candida./i. too. All cave animals showed low preference for offered food and have tendency to stay rather on clay cave sediment then on the food.
Vybrané fyziologické parametry žížaly .i.Dendrobaena mrazeki./i. (Černosvitov, 1935)
Šustr, Vladimír ; Pižl, Václav
.i.Dendrobaena mrazeki./i. shows preferences for xerothermic habitats, i.e. behaviour unusual for Central European earthworms. Several ecophysiological parameters of .i.D. mrazeki./i. were measured as a basis for further investigation of its environmental adaptations. pH about 7 prevailed in the gut of the species. The profile of digestive enzymes included all important saccharolytic enzymes and did not differ from those of other earthworms indicating no exclusivity in .i.D. mrazeki./i. feeding habits. Melting and supercooling points of body fluid were similar to those of relative species .i.D. octaedra./i.. The adaptation of .i.D. mrazeki./i. to xerothermic habitats may result from its desiccation tolerance, ability of quiescence and/or from its partly endogeic mode of life. Quiescent adult individuals were found to survive about 60 days at 15 % soil moisture.
Příjem potravy a metabolická aktivita .i.Galumna elimata./i. (C.L. Koch, 1841) (Acari: Oribatida) při různých teplotách
Šustr, Vladimír ; Hubert, J. ; Pekár, S.
The ability of the physiological compensation of respiration rate and feeding activity for temperature was tested in oribatid mite .i.Galumna elimata./i. to evaluate significance of the increase of amylolytic activity in the whole body homogenates of mite exposed to cold acclimation. Mites were reared on green bark algae (.i.Protococcus viridis./i.) at different constant temperatures (5-30°C) for 21 days. The temperature relationships of respiration rate, presence of animals on food and defecation were compared before acclimation (quick response to temperature change) and after acclimation to constant temperature (effects of adaptation). The relationship of oxygen consumption on temperature was similar in control and acclimated mites. Presence of animals on food increased exponentially with temperature before acclimation. It was higher at 15°C after acclimation at constant temperature.
Energetika larev tří druhů čeledi Bibionidae
Frouz, Jan ; Šustr, Vladimír ; Kalčík, Jiří
Food consumption, defecation, assimilation and production were studied in three species of bibionid larvae (.i.Bibio marci, B. pomonae, Penthetria holosericea./i.) feeding either on leaf litter or their own excrements. Assimilation efficiency of larvae feeding on leaf litter was in all species higher then assimilation efficiency of the same species feeding on their own excrements. Larvae reared on excrements also lost weight, which indicated that excrements were insufficient as an exclusive source of energy. In .i. B. marci, P. holosericea./i. the effect of temperature on assimilation efficiency was studied. In .i. P. holosericea./i. assimilation efficiency decreased with increasing temperature. This trend was not observed in .i. B. marci. B. marci./i. was fed on pure cellulose to test if cellulose can serve as the only source of energy. Mortality of larvae feeding on cellulose was significantly higher than of those feeding on leaf litter and did not differ from starving larvae.

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1 Šustr, Vít
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