Effect of salinity on survival, oxygen consumption and hematological response of greenling Hexagrammos otakii

Abstract

The mortality of fish was not found in the range of 33.4 to 14.5 psu, but survival rate was reduced to 50.0% at 3.8 psu after exposure for 96 hr. The mean OCRs of 33.4, 33.1, 32.8, 32.2, 31.0, 28.7, 23.9, 14.5 and 3.8 psu were 281.4, 279.8, 279.6, 279.0, 280.0, 279.6, 387.8, 334.4 and 99.8 mg kg fish-1 hr-1, respectively. The OCRs were not significantly different in the range 33.4 to 28.7 psu (P>0.05), but significantly increased at 23.9 and 14.5 psu, and then suddenly decreased at 3.8 psu compared to control (P<0.05). The change of salinity in fish did not affect the hematological variables such as hemoglobin, glucose, GOT (glutamic oxaloacetic transaminase), K+ and Cl- compared to control. The concentrations of GPT (glutamic pyruvic transaminase) in fish exposed in the range of 28.7 to 3.8 psu were significantly lower than that of control fish (P<0.05). The concentrations of glucose and hematocrit in fish exposed at 14.5 and 3.8 psu were significantly lower than those of control fish (P<0.05). The concentrations of plasma Na+ were significantly lower in fish exposed at 3.8 psu compared to control (P<0.05). The results of this study provide evidence that H. otakii exposed to below 28.7 psu have significant physiological response to tolerate salinity changes. 279.6, 279.0, 280.0, 279.6, 387.8, 334.4 and 99.8 mg kg fish-1 hr-1, respectively. The OCRs were not significantly different in the range 33.4 to 28.7 psu (P>0.05), but significantly increased at 23.9 and 14.5 psu, and then suddenly decreased at 3.8 psu compared to control (P<0.05). The change of salinity in fish did not affect the hematological variables such as hemoglobin, glucose, GOT (glutamic oxaloacetic transaminase), K+ and Cl- compared to control. The concentrations of GPT (glutamic pyruvic transaminase) in fish exposed in the range of 28.7 to 3.8 psu were significantly lower than that of control fish (P<0.05). The concentrations of glucose and hematocrit in fish exposed at 14.5 and 3.8 psu were significantly lower than those of control fish (P<0.05). The concentrations of plasma Na+ were significantly lower in fish exposed at 3.8 psu compared to control (P<0.05). The results of this study provide evidence that H. otakii exposed to below 28.7 psu have significant physiological response to tolerate salinity changes.