Abstract: The activities of liver superoxide dismutase (SOD) and catalase (CAT), total count of blood cells, and gill Na+-K+-ATPase activity were measured in adult tomato clownfishAmphiprionfrenatuswith body weight of (5.42±1.29)g exposed to a salinity of 31, 25 and 20 for 3 h, 12 h and 48 h to study the effect of low salinity stress on the physiological indices of the tomato clownfish. No dead tomato clownfish were observed in three experimental groups during the low salinity stress. However, the total number of blood cells was found to be decreased with decreasing salinity for 48 h salinity stress, significantly lower at salinity of 20 in 48 h exposure than that in the other two groups (P<0.05). The activity of Na+-K+-ATPase (NKA) was increased firstly and then decreased with the change in salinity under a salinity of 20 and 25, significantly higher a salinity of 25 than those in the control group and in the 20 salinity group during the whole stress period (P<0.05). In liver SOD activities were higher in the fish exposed to salinity of 20 and 25 than that in the control group. During the whole experiment, the CAT activity in salinity of 20 was significantly different from that in the control group (P<0.05); significantly lower in the salinity of 25 than that in the control group only in 48 h (P<0.05). The findings indicate that lower salinity (20 and 25) for 48 h will affect count of blood cells, and activities of Na+-K+-ATPase and CAT instead of survival and growth of tomato clownfish during the experiment stage, providing basis with the desalination culture of tomato clownfish.
2018, Vol. 33 
