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Porovnání populací okouna říčního (Perca fluviatilis L.) z intenzivní akvakultury - vliv původu ryb na chování a kritickou rychlost plavání.
TOMÁŠEK, Ondřej
European perch is one of potential fish for breeding in conditions of intensive aquaculture. This species of fish is in relatively high demand, especially in the Alpine region, because of its very tasty meat. The relatively high price of fillets is attractive for producers. The difficulties in perch farming in conditions of European intensive aquaculture may alleviate the further domestication process of this species or its selective breeding. These pitfalls are negatively correlated with fish welfare. In this thesis, we examined morphometric (morphometry, fin damage, somatic index), behavioural (activity, aggressivity, boldness and critical swimming speed) and physiological (cortisol, glucose, enzyme activity, potassium) parameters in four populations of perch imported from different European intensive farms (France - two farms, Hungary, Denmark) engaged in their producing. Experiments performed in this thesis showed that individuals from the Danish population has the highest activity of the studied populations, including the critical swimming speed (4.24 ? 0.15 BL.sec-1). The population from Denmark also found the highest percentage (8.9 %) of bold exploratory behaviour, which subsequently increased aggressive behaviour within this population. The number of attacks on other individuals from the flock reached the highest measured values in this experiment (2.33 ? 2.31 attacks). Furthermore, experiments showed that individuals from the Danish population showed a higher tolerance for adverse environmental problems compared to other populations from Hungary or France. These differences, which have been observed in the Danish population, can be interpreted as a proactive stress mechanism that is characteristic of fast pace syndrome (fast POLS). High perivisceral fat index was found in fish from the Hungary. The morphometric characteristics of all populations were significantly different. Genomic characteristics could address this approach in the near future, in particular to streamline domestication processes and support the selective breeding of perch suitable for European intensive aquaculture.
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