Physiological and genetic correlates of boldness: Characterising the mechanisms of behavioural variation in rainbow trout, Oncorhynchus mykiss

►Bold and shy behaviour were clearly differentiated in both HR and LR lines of trout ►Post-stress cortisol levels were significantly higher in HR than LR trout ►Expression of novel candidate genes significantly differed between the stress lines ►No relationship between boldness and cortisol levels or gene expression were found