Species specificity in the magnitude and duration of the acute stress response in Mediterranean marine fish in culture

The aim of the present study was to examine the species-specific stress response for seven Mediterranean fishes in culture. Also, to evaluate the method of measuring free cortisol concentration in the rearing water as a non-invasive and reliable indicator of stress in marine species, of aquaculture importance. Gilthead sea bream, Sparus aurata (Sparidae); common dentex, Dentex dentex (Sparidae); common Pandora, Pagellus erythrinus (Sparidae); sharpsnout sea bream, Diplodus puntazzo (Sparidae); dusky grouper, Epinephelus marginatus (Serranidae); meagre, Argyrosomus regius (Sciaenidae) and European sea bass, Dicentrarchus labrax (Moronidae) were subjected to identical acute stress (5–6 min chasing and 1–1.5 min air exposure) under the same environmental conditions and samples were analyzed by the same procedures. Results indicated that there was a clear species-specificity in the magnitude, timing and duration of the stress response in terms of cortisol, glucose and lactate. European sea bass showed a very high response and dusky grouper and meagre a very low response, except plasma glucose concentrations of dusky grouper which was constantly high, while sharpsnout sea bream presented a protracted stress response, up to 8 h. The present study confirmed that free cortisol release rate into the water can be used as a reliable stress indicator.

► We examine the stress response of seven Mediterranean fishes.
► Evaluate cortisol release rate in the water as non-invasive stress indicator in marine species.
► There are differences in magnitude and duration of the stress response between species.
► Cortisol release rate into the water can be used as a reliable stress indicator.
► Freshwater fish species have higher cortisol release rates than seawater species.