Effects of salinity change on immune factors of hybrid abalone (Haliotis discus hannai Ino)

Hybrid abalones Haliotis discus hannai Ino(♀)×H. discus discus Ino(♂), were exposed to different salinity in their all life, but how immune parameters changeed when the salinity changed was still uncertain. In this study, we investigated the changes of serum superoxide dismutase (SOD), alkaline phosphatase (AKP), catalase (CAT), lysozyme (LZM) and bactericidal (Ua) activities when the salinity stepwise changed from 34 to 16, 22, 28, 40 within 48 h. It aimed to study effects of gradient salinity on immune-related factors.The results showed that five immune factors change was not significant at salinity 28, 34 (control group) during the experiment. In salinity 40 group, AKP activity was significantly lower than the control group in all experiment, CAT activity significantly increased at first and then gradually decreased, significantly lower than the control group at last level, LZM activity declined and gradually stayed stable at a significantly lower value than the control group at last. In salinity 22 group, AKP activity had a downward trendy, and significantly lower than the control group at 48 h. In salinity 16 group, SOD, AKP, LZM activity and bactericidal activities had a downward trend, significantly lower than the control group at 48 h, CAT vitality was significantly lower than the control group in all detection periods. The results indicated that when the salinity closed to or higher than 40 and closed to or below 16, the activity of serum immune factors even immunity in hybrid abalone were significantly influenced.