Differential responses to environmental challenge by common carp Cyprinus carpio highlight the importance of coping style in integrative physiology.

Common carp Cyprinus carpio displaying proactive or reactive stress coping styles were acclimated to two environmental regimes (low oxygen and low temperature), and selected groups were tested for response to an inflammatory challenge (Escherichia coli lipopolysaccharide, LPS). Plasma glucose and lactate levels were measured, as were selected C. carpio-specific messenger (m)RNA transcript abundance, including cortisol receptor (CR), enolase (ENO), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and interleukin-1-beta (IL1β) was measured in individual whole brain samples.

Fish can show emotional fever: stress-induced hyperthermia in zebrafish.

Whether fishes are sentient beings remains an unresolved and controversial question. Among characteristics thought to reflect a low level of sentience in fishes is an inability to show stress-induced hyperthermia (SIH), a transient rise in body temperature shown in response to a variety of stressors. This is a real fever response, so is often referred to as 'emotional fever'.

Cue-based and algorithmic learning in common carp: A possible link to stress coping style.

Common carp that had been screened for stress coping style using a standard behavioural test (response to a novel environment) were given a learning task in which food was concealed in one of two compartments, its location randomised between trials and its presence in a given compartment signalled by either a red or a yellow light. All the fish learned to find food quickly, but did so in different ways. Fifty five percent learned to use the light cue to locate food; the remainder achieved the same result by developing a fixed movement routine.