NKFIH K112070 Az intenzív tartás körülmények szelekciós hatásának vizsgálata süllő populációkban
The natural behaviour of the pikeperch foraging on live prey fish has to be altered to an experienced behaviour (pellet feeding) for the intensive production. However, not all of the individuals are able to maintain this process resulting significant losses during the transition. Former investigations demonstrated that the correlations of behaviour forms evolve an animal “personality” (similarly to the human), which has varying reaction under different conditions. The effect of personality type of pikeperch (determined as a correlation of foraging, explorative behaviours and stress tolerance) will be explored on the production traits of the individuals in the recent project. Additionally, it will be tested by molecular genetic tools, what kind of changes could be appeared in the genetic structure of the stock due to a behaviour-based selection coupled with hormone induced propagation (sorting only the individuals adapted to the intensive conditions well), and whether the personality type of the individual could be indicated without the testing of the behaviour.

NKFIH K143458 Genetic analyses of potential effects of stress on feeding behaviour, feed intake and feeding efficiency in intensively reared pikeperch
During the intensive culture of the pikeperch pelleted foods are offered instead of the natural live prey. The success of the pelleted food consumption significantly influences the effectivity and economy of the production. During the weaning process the fish learn to consume the compound feed, and this is driven by the opposite effect of stress and appetite. Similarly, to the weaning, the same process is supposed to influence the consumption of a new food during a diet change. In our project we study the expression of the candidate genes for stress and appetite to explore their relationship with the consumption of new foods at the critical points of the diet change. Additionally, we compare the total expressed RNA of the individuals consuming and refusing the new foods to identify further genes involved in the process. Since the occurrence of cannibalism could be regulated similarly to the processes described above, the examinations will be performed also with the comparison of cannibalistic and normal individuals. The measurement of the individual differences in the feed intake in fish is not wildly used because of its high labour requirement, but it allows to select the individuals with higher food consumption and better food conversion, and also to map the genetic background behind the individual variation. The final aim of our project is measuring the individual feed intake and conversion, identifying the genes regulating them, and exploring polymorphisms (mutations) which allow to select the individuals with excellent production.