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Pollution produced carp general, depending on the fullness of the digestive tract.
HAVLÍNOVÁ, Šárka
The aim of my bachelor thesis was to determine and compare the differences in the levels of pollution produced by fish through their metabolic activities depending on the fullness of their digestive tract. The pollution production was detected in 4 groups of fry of the common carp: 1) the fish had no access to food for 2 days before the beginning of the experiment; 2) the fish did not eat for 10 days before the beginning of the experiment; 3) the fish had a limited food intake (pellets KP1) before the beginning of the experiment; 4) the fish accepted spontaneously feed (2% by weight of the stock). The experiments were carried out in laboratory conditions. In the beginning of the experiment, the fish of individual groups and known weight were placed in experimental aquariums filled with 20 l of tap water. The experiments took 24 hours and after that the fish were moved back into its origin tank. Water from the experimental aquariums was filtered through a screen with 40 micrometr mesh size. Both, filtered water ("aqueous phase excrements") and solids ("solid phase excrements") were analysed. Solids were analysed for a content of dry matter, total phosphorus (P) and nitrogen (N). Filtered water was analysed for a concentration of suspended solids, total nitrogen, total ammonia, total phosphorus, chemical oxygen demand (CODMn, and CODCr) and biochemical oxygen demand (BOD5). Aqueous phase excrements was filtered again through a glass filter (1.2 micrometr) and the filtrate was analysed for concentration of ammonia nitrogen [N (NH3 + NH4+)], nitrate nitrogen [N-NO3-] and orthophosphate phosphorus [P-PO43-]. Pollution detected in solids and in filtered water was related to 1 kg of live weight of fish per day. The parameters characterizing pollution excreted by fish achieved in the 4th group i.e. fish, which accepted spontaneously feed the highest values. The fish of this group secreted on average of 4,154 mg.kg-1.day-1 of suspended solids (particles 1.2 micrometr), 105,5 mg.kg-1.day-1 of total phosphorus and 1,342 mg.kg-1.day-1 of total nitrogen. In the aqueous phase excrements, there was detected on average of 637 mg.kg-1.day-1 of ammonia nitrogen 4.9 mg.kg-1.day-1 of phosphate phosphorus.4,561 mg.kg-1.day-1 of CODCr, 2,634 mg.kg-1.day- 1 of BOD5. The values detected in the other groups were times lower.
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The effect of oribatid mites on the composition of fungal community in pine litter
Černá, Kristýna ; Koukol, Ondřej (advisor) ; Hubert, Jan (referee)
4 Abstract The aim of this study was to determine whether oribatid mites affect the variety of fungi in litter of Scots pine (Pinus sylvestris), and if the dispersibility of fungi particles is related to oribatid mite species. To this end, I have prepared several semi-natural systems, in which I observed dispersion of fungi separately and in the presence of two oribatid mite species: Phthiracarus sp. and Adoristes ovatus. I assessed the experiment in two ways, by a cultivation of washed needles on agar medium and direct observation of needles under a binocular magnifier. In the next part of this study I isolated particles of fungi present on the surface and in the faeces of oribatid mites Adoristes ovatus, Porobelba spinosa and Spatiodamaeus verticillipes and compared it with the respective oribatid mite species. The most frequent needles fungi spread by oribatid mites were Oidiodendron maius var. maius, Oidiodendron muniellense, Oidiodendron setiferum, Umbelopsis ramanniana, Mucor hiemalis f. hiemalis and Mortierella hyalina. On the mites body surface the most commonly recorded fungi were Beauveria bassiana, Umbelopsis ramanniana, Cladosporium cladosporioides s.l., Cladosporium herbarum s.l. and unknown species of the genus Penicillium. Fungi species Acrodontium crateriforme, Umbelopsis ramanniana and...
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