National Repository of Grey Literature 2 records found  Search took 0.00 seconds. 
Vliv teplotních a hyperoxických podmínek na růst, příjem krmiva a fyziologii hybrida sivena arktického (Salvelinus alpinus Linnaeus, 1758) a sivena amerického (Salvelinus fontinalis Mitchill, 1815)
ČEJKA, Jakub
This diploma thesis should have tested growth abilities during different temperature and oxygen regime in hybrid between brook trout (Salvelinus fontinalis) and arctic charr (Salvelinus alpinus) culture. There were survival, growth, feed conversion, weight heterogeneity of fish and somatic indexes as followed indicators. The hypothesis was discovery of differences in growth and mentioned indicators during rearing in water with different temperature and oxygen regime. This thesis consists of two done experiments. There were tested five temperature regimes (7, 10, 13, 16 and 19 °C) in the first experiment. Each of tested groups was repeated four times. The experiment took place 84 days and biometric data were measured always after 21 days period. Results showed that the highest weight growth was achieved in fish reared at 13 °C as specific growth rate achieved 4,12 ? 0,21 % × day-1. Higher temperature regimes (16, 19 °C) are not suitable for rearing of Salvelinus hybrid. Survival of tested group reared at 19 °C were only 41,4 ? 27,3 % after the end of the first experiment. At lower temperatures efficient feed conversion were not managed and specific growth rate were lower than at mentioned temperature 13 °C. There were four tested groups permanent hyperoxia (120 130 %), hyperoxia only during a light part of a day, oscillating hyperoxia/normoxia and permanent normoxia (85 95 %) in the second experiment. Each of tested groups was repeated three times. The experiment took place 63 days and biometric data were measured always after 21 days. There were no difference in survival among tested groups and after the end of the second experiment survival was 86,0 ? 1,4 %. The highest specific growth rate were achieved at the normoxia group 1,48 ? 0,05 % × day-1 and at the group where fish were reared under hyperoxia only during a light part of a day - 1,38 ? 0,10 % × day-1. The most efficient feed conversion was mentioned at the fish reared in permanent normoxia and permanent hyperoxia.
Comparison of ichtyofauna in morphologically similar parts of trout zone of two rivers with different kind of management
ČEJKA, Jakub
The topic of this bachelor´s paper is comparison of biodiversity of fish community in morphologically similar parts of two South Bohemian rivers the Malše and the Blanice, which vary in the kind of fish management. There were chosen four parts of both rivers in the trout to the grayling zone, which were fished with a power generator in spring and autumn 2015. Fished fish, which are important for the fish management, were measured and weighed individually and then all the fish were given back to the parts. Gained data were processed. The parts, which were compared, are CHRO (freshwater fish protected areas), areas, where only original species are handled (brown trout (Salmo trutta m. fario, Linnaeus, 1758) and european grayling (Thymallus thymallus, Linnaeus, 1758)) and areas, where apart of original species rainbow trout popular with sport fishermen (Oncorhynchus mykiss, Walbaum, 1792) is handled. A similar trend of higher stability and condition of original species population in higher located parts of monitored fish district of both rivers was found out. There is a probable dependence of brown trout´s and grayling´s presence on handling of fries, which are heavily influenced by the presence of unoriginal species and sport fishing in the lower parts of the Malše river. It is possible to assume the existence of natural reproduction and subsequent sustainability of both species populations in the above-lying areas. The population of brown trout in the Blanice river can be judged like sustainable by itself in all the parts and influenced by undesirable fish species only in the lower parts. The presence of grayling in all the parts is probably dependent on fish migration from the lower part of the district and there is grayling only sporadic in the higher located parts.

See also: similar author names
4 ČEJKA, Jan
1 ČEJKA, Jaroslav
1 ČEJKA, Jindřich
3 Čejka, Jakub
4 Čejka, Jan
7 Čejka, Jiří
3 Čejka, Josef
Interested in being notified about new results for this query?
Subscribe to the RSS feed.