Impact of Stress Coping Styles on Serum Protein Electrophoresis Pattern Modulation in Sparus aurata Following Vibrio anguillarum Inoculation

Stress coping style (SCS) is crucial for animal welfare in the context of breeding. The link between behavioural traits and physiological responses to external stimuli is increasingly recognized and could orient the selection of appropriate SCSs for welfare-oriented breeding. This study aimed to evaluate how SCS influences the physiological responses of Sparus aurata, a widely used species in aquaculture, following Vibrio anguillarum stimulation. To this end, the serum protein electrophoretic profile, analysed by capillary electrophoresis, was used as an innovative parameter to assess physiological variations. S. aurata individuals were categorized into three SCS groups—bold, shy, and intermediate —based on a risk-taking test. Serum was collected at day 0 (pre-inactivated V. anguillarum inoculation) and at 30 and 60 days post-inoculation. Analyses revealed an increase in the β2-globulin fraction, putatively associated with molecules involved in the physiological response following inactivated pathogen inoculation, accompanied by a decrease in the γ fraction over time. This trend was particularly pronounced in bold fish, while shy ones showed a similar but less marked pattern. Overall, the results suggest that proactive individuals exhibit a more marked physiological modulation to inactivated pathogen stimulation than reactive ones, highlighting modulation of serum protein electrophoresis as a sensitive bioindicator of physiological response in S. aurata.