Physiological responses of Yellowfin seabream (Acanthopagrus latus) to acute salinity challenge

ABSTRACT One hundred and eight juvenile Acanthopagrus latus were transported from their natural habitat and kept in tanks (300 L) with 20 ppt salinity for 14 days. After 24h starvation, the fish were exposed to salinity of 34, 12, and 5 ppt; then, blood samples were taken after 0, 2, 24, and 48h after the exposure. Blood electrolytes did not show significant changes in response to variation in the environmental salinities. Cortisol and ALP increased (not significantly) in all groups after 2h (P<0.05) and returned to the basal value within 24 h. Glucose and lactate levels increased significantly in all experimental groups after 2h (P<0.05) and returned to the basal value within 48 and 24h, respectively. Triglyceride did not show any significant change during the trial. Our findings showed juvenile A. latus could acclimate to a range of salinities from 5% to 35% within 48h. Also, the metabolic changes were more related to the time of sampling than the salinity challenge, suggesting that adaption occurred during the time of the study.