Stress, pain and welfare of fish

Results from this Chapter provided evidence of mutual assessment in rainbow trout, provided evidence of higher levels of aggression in homogenous pairs of fish, and illustrated that aggression in heterogenous pairs of trout was absent until the addition of a resource (food).<br><br>The second experimental Chapter of the thesis (Chapter 3) looked at the effect of feeding levels and group size on the behaviour of farmed rainbow trout.

Results from this Chapter provided evidence of reduced aggression levels at higher food densities, provided evidence of increased aggression levels in smaller group sizes, and illustrated that group size has less of an effect on behaviour when food is more readily available.<br><br>The third experimental Chapter of the thesis (Chapter 4) looked at trade offs between feeding and shock avoidance in the goldfish. Results from this Chapter provided evidence of an emotional experience of pain in the goldfish, illustrated by the trade off between shock avoidance and feeding.