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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.
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