Effect of suspended solid on survival, oxygen consumption and blood cortisol of Sebastes inermis and Acanthopagrus schlegelii

Abstract

The effect of suspended solid (SS) on survival, oxygen consumption and blood cortisol of dark-banded rockfish Sebastes inermis (mean body weight of 45.5 g) and blackhead seabream Acanthopagrus schleglii (38.8 g) was investigated at seven different SS of 2.5, 5, 10, 20, 40 60 and 80 mg/L, respectively. Survival and blood cortisol were measured at each SS in two separate trials of 96- and 48-hr duration. Oxygen consumption rate (OCR) was determined under each SS concentration at an interval of 5 minutes for 24 hours using a continuous flow-through respirometer. No death of two different fishes was observed for all SS concentrations. The OCRs of S. inermis were not significantly different in the range of 2.5 to 5.0 mg/L (P > 0.05), but significantly increased until 20 mg/L and then gradually decreased until 80 mg/L (P < 0.05). The OCRs of A. schlegelii were not significantly different in the range of 2.5 to 40.0 mg/L (P > 0.05), but significantly decreased until 80 mg/L (P < 0.05). The cortisol concentrations of S. inermis were not significantly affected by SS concentration (P > 0.05). The cortisol concentrations of A. schlegelii were not significantly different in the range of 0 to 10.0 mg/L (P > 0.05), but significantly increase in range of 20 to 80 mg/L (P < 0.05).fferent SS of 2.5, 5, 10, 20, 40 60 and 80 mg/L, respectively. Survival and blood cortisol were measured at each SS in two separate trials of 96- and 48-hr duration. Oxygen consumption rate (OCR) was determined under each SS concentration at an interval of 5 minutes for 24 hours using a continuous flow-through respirometer. No death of two different fishes was observed for all SS concentrations. The OCRs of S. inermis were not significantly different in the range of 2.5 to 5.0 mg/L (P > 0.05), but significantly increased until 20 mg/L and then gradually decreased until 80 mg/L (P < 0.05). The OCRs of A. schlegelii were not significantly different in the range of 2.5 to 40.0 mg/L (P > 0.05), but significantly decreased until 80 mg/L (P < 0.05). The cortisol concentrations of S. inermis were not significantly affected by SS concentration (P > 0.05). The cortisol concentrations of A. schlegelii were not significantly different in the range of 0 to 10.0 mg/L (P > 0.05), but significantly increase in range of 20 to 80 mg/L (P < 0.05).