Multidimensionality of behavioural phenotypes in Atlantic cod, Gadus morhua.

Much of the inter-individual variation observed in animal behaviour is now attributed to the existence of behavioural phenotypes or animal personalities. Such phenotypes may be fundamental to fisheries and aquaculture, yet there have been few detailed studies of this phenomenon in exploited marine animals. We investigated the behavioural and neuroendocrine responses of Atlantic cod (Gadus morhua L.

Behavioural responses of hatchery-reared and wild cod Gadus morhua to mechano-acoustic predator signals.

The behavioural responses of wild (predator-experienced) and hatchery-reared (predator-naive) cod Gadus morhua to standardized mechano-acoustic (MA) stimuli were compared in the laboratory. Wild fish responded mainly with freezing and fast-start escapes away from the stimulus, whereas hatchery-reared fish often ignored or approached the stimulus. Wild fish also had stronger responses, turning faster during escapes and reducing activity immediately after the stimulus.