Effects of pH stress on survival rate and activities of iontransport enzyme, immunerelated enzymes in three species of shrimps

Abstract:

The survival rate, gill Na⁺-K⁺-ATPase activities and serum iNOS, PO, SOD, GSHPX, LSZ activities were compared in Fenneropenaeus chinensis, Litopenaeus vannamei and Marsupenaeus japonicus which were reared under control group (pH 8.2), low (pH 7.2), and high (pH 9.2) pH stress conditions in this study. Results showed that there were no negative effects among three species of shrimps when reared in the control group for 96 h. Under low or high pH stress conditions, the survival rates of M. japonicus, L. vannamei and F. chinensis for 96 h were 96.7% and 97.0%, 60.1% and 54.6%, 58.6％ and 13.3％, respectively. With respect to gill Na⁺-K⁺-ATPase activity, L. vannamei showed highest level and M. japonicus was lowest in control group. The change in gill Na⁺-K⁺-ATPase activity of F. chinensis was the biggest. But that of M. japonicas was smallest under both low and high pH stress conditions. Also, all three species of shrimps tend to change much more in gill Na⁺-K⁺-ATPase activity under pH 9.2. In the control, the activities of nonspecific immunityrelated enzymes of both L. vannamei and M. japonicus were significantly higher than that of F. chinensis and PO and SOD activities of M. japonicus were markedly higher than that of L. vannamei, while the LSZ activity of L. vannamei was higher than that of M. japonicus. The changes in nonspecific immunityrelated enzymatic activities for F. chinensis and L. vannamei were much higher than that for M. japonicus both in low and high pH stress conditions for 96 h. Serum iNOS, SOD, GSHPX and LSZ activity in F. chinensis and L. vannamei tended to change much more than in M. japonicas under low pH stress. The data obtained in the study indicated that M. japonicus has the strongest tolerance for pH stress among three species, then L. vannamei, and F. chinensis was the lowest.