Abstract:Experiments were done to investigate the effect of low salinity stress on the digestive enzymes, anti stress enzymes and the survival rate of juvenile Epinephelus malabaricus. The larvae were reared in seawater and the salinity was reduced from 28.23 to 22.56, 17.57, 12.67 and 7.71 succesively in every three days. The digestive enzymes, anti stress enzymes and the survival status were determined. The results showed that the protease and amylase activities in both stomach and intestines of the fish reduced significantly with the decrease of the salinity (P<0.05). The activity of SOD increased, while CAT and GSH-Px in liver, muscle and kidney declined with the decrease of the salinity. In addition, mortality appeared when salinity was 12.67, and all the juvenile fish died within 12 hours when the salinity was 7.71. Hence, the digestive enzymes and anti stress system of juvenileE. malabaricus were affected seriously by low salinity stress and would ultimately affect the healthy growth of juvenile fish.
