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1	REZISTENCE EMBRYÍ NĚKTERÝCH DRUHŮ RYB KE KRYOPROTEKTIVŮM PŘI NÍZKÝCH TEPLOTÁCH / Resistance of some species of fish embryos to cryoprotectants at low temperatures ALDORF, Milan January 2007 (has links) Different cryoprotectant media for cryopreservation of embryos has been tested on model species, i.e. common carp (Cyprinus carpio) and common tench (Tinca tinca). The aim of the study was to obtain such cryoprotectants, which will be acceptable for freezing embryos up to the temperature {--}196 oC. Cryoprotectants of 10 % and 20 % methanol or 10 % and 20 % glycerin have been tested on the tench for 21 minutes of incubation on embryos of four stages, meaning at 11, 17, 23 and 29-hrs after activation of gametes. The results showed that the tench embryos were most resistant either to low temperature and or to the application of cryoprotectants in the stage of 29-hrs post gametes activation. On the other hand lower resistances were obtained in the stage of 11-hrs post gamete activation. Embryos of carp 2, 6, 22, 24 and 42-hrs after gametes activation at temperature 18 and 22 oC have been used for testing of concentration series of cryoprotectant methanol and two solutions marked VS1 and VS2 after previous disruption of egg envelope in enzyme alcalaze solution. Results showed linear decreasing resistance of embryos depending on increasing concentration of cryoprotectant methanol. Hatching success even at highest concentration of solution VS1 and VS2 has not declined below 70 %. Achieved results with solution VS2 have been subsequently used for freezing of carp embryos by special methods in cryobiology {--} vitrification. First results showed up to 4 % success of survival after freezing of embryos at {$-$}196 oC.
2	Variability of lipid classes and fatty acid composition during over ripening of oocytes from tench (\kur{Tinca tinca}) KRZYŚKÓW, Anna January 2017 (has links) In this project, the eggs of tench (Tinca tinca) were used for the evaluation of changes in fatty acid (FA) composition and lipid classes during in vitro ova ageing until the occurrence of over-ripening. Stripped ova of 6 females were collected separately and stored in sterile cell culture plates in an incubator at 20 °C for up to 24 hours post stripping (HPS). Stored ova were fertilized at 0, 2, 4, 6, 8, 10 and 24 HPS. Egg eyeing and hatching rates were assessed as indices of egg quality. Upon fertilization at each HPS, samples were taken separately frozen in liquid nitrogen and stored at -80°C till further analyses. Differences in the FA and lipid composition and embryo survival rates at the different fertilization times post-stripping were evaluated. The lipid fraction was extracted from the oocytes according to Hara and Radin (1978). The lipid content of the samples was determined gravimetrically from total extracted lipid. The FA were then analysed with a gas chromatograph equipped with a flame ionisation detector and PVT injector. The peaks were identified by comparing their retention times with those of authentic standards. Major lipid classes and the phospholipid classes were separated according to (Olsen and Henderson, 1989). Quantitative analysis of the separated lipid- and phospholipid classes was done by scanning the plates after derivatisation with a CAMAG TLC Scanner 3 (Camag, Switzerland). Identification of the lipid classes was performed by comparison with authentic standards applied on the same plate. In present study no significant changes were observed in lipid content and composition during storage of eggs until over-ripening. As well FA composition did not change over time indicating another reason of deterioration of oocyte quality than the proposed lipid oxidation. However individual fishes in this study showed much different fertilization rates that corresponded with their levels of cholesterol and triacylglycerols in minor degree.
3	Ritmos de actividad motora, comportamiento alimentario e influencia de la melatonina exógena en peces teleósteos Herrero Ramón, María Jesús 26 October 2007 (has links) La presente Tesis Doctoral tiene como objetivo profundizar en los conocimientos sobre ritmos biológicos y comportamiento alimentario de tres especies de peces teleósteos de interés en acuicultura: tenca (Tinca tinca), trucha alpina (Salvelinus alpinus) y lubina (Dicentrarchus labrax).Con este fin se ha investigado la influencia de factores bióticos y abióticos en la sincronización de los ritmos de actividad locomotora y alimentaria, así como el carácter endógeno y/o exógeno de estos ritmos. A su vez, se ha profundizado en el comportamiento individual de truchas alpinas mantenidas en grupo, mediante una nueva metodología que permite estudiar los ritmos de demanda voluntaria de alimento y la autoselección dietaria de los individuos. Asimismo, se ha analizado la influencia de los niveles endógenos de melatonina, modificados mediante la administración de melatonina exógena y de su aminoácido precursor (triptófano) en la dieta, sobre la concentración de cortisol y el ritmo de actividad locomotora en lubina. / This Doctoral Thesis deeps into the knowledge about biological rhythms and feeding behaviour in three teleostean fish species of interest in aquaculture: tench (Tinca tinca), Arctic charr (Salvelinus alpinus) and European sea bass (Dicentrarchus labrax). With this aim, the influence of biotic and abiotic factors has been researched in the field of synchronization of locomotor and feeding rhythms, as far as the endogenous or exogenous character of these rhythms. Moreover, individual feeding behaviour of Arctic charr kept in groups has been studied trying a new methodology which allows the monitoring of feeding demands and dietary self-selection of individuals. Furthermore, influence of endogenous melatonin modified through exogenous melatonin and its precursor amino acid (tryptophan) administration in the diet, in the cortisol levels and locomotor activity rhythms in sea bass were analysed. Dicentrarchus labrax Salvelinus alpinus Tinca tinca sea bass Arctic charr tench fish aquaculture tryptophan melatonin feeding behaviour exogenous endogenous pacemaker biological rhythms Dicentrarchus labrax Salvelinus alpinus Tinca tinca lubina trucha alpina tenca peces acuicultura triptófano melatonina comportamiento alimentario exógeno endógeno oscilador ritmos biológicos Fisiología Animal 5 57 59 612

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