Behavior and physiological status of pond-cultured pikeperch (Sander lucioperca) broodstock effected by sexual interactions throughout semi-artificial reproduction

This study investigated physiological and behavioral responses of pikeperch broodstock related to sexual interactions under controlled conditions throughout semi-artificial reproduction. Blood samples taken from pond-cultured pikeperch broodstock were analyzed to assess the stress response at different stages of semi-artificial reproduction protocol. Sampling was performed as follows: before hormonal induction (control), 24 h (SP24) and 48 h (SP48) after spawning when males and females were separated, and 24 h (NS24) and 48 h (NS48) after spawning when males and females were kept together. The separation immediately after spawning had a significant effect on physiological state of broodstock. Separation affected indices of erythrocyte count, hematocrit (packed cell volume, PCV), glucose (GLU), and mean corpuscular volume (MCV) in females and levels of lactate and leukocytes in males. Monitoring of pikeperch behavior in groups NS24 and NS48 revealed the strong aggressive paternal behavior of male to females. Attacks mainly targeted the caudal fin and resulted in female mortality in group NS48.