It is widely accepted that animals adopt behaviours along a “bold/shy” spectrum in order to improve chances of survival in the wild. Findings from various studies suggest these traits have ecological and evolutionary significance. The objectives of this study were to: 1) investigate whether bold/shy behaviours differ between hatchery reared and wild Murray cod; 2) evaluate whether common carp and Murray cod of different sizes and ages differ in their bold/shy behaviours; and 3) assess the extent in which bold/shy behaviours are correlated with growth rate. Hatchery-reared Murray cod were more bold than wild fishes in emergence, exploration and predator-approach trials, while patterns of behaviour of invasive common carp showed higher variability. We discuss the implications of our results in relation to the survival of hatchery released Murray cod and the success of invasive common carp in Australia.