Effects of Temperature and Salinity on Tissue Structure, Antioxidant Capacity, and Heat-Shock Protein Gene Expression in Penaeus monodon

Four experimental groups (normal temperature and normal salt-Control group, normal temperature and low salt-Group A, high temperature and low salt-Group B, and high temperature and normal salt-Group C) were set to explore the effects of temperature and salinity on the stress response of the black tiger shrimp, Penaeus monodon. During the experiment conducted for 96 h, the levels of acid phosphatase (ACP), alkaline phosphatase (AKP), total superoxide dismutase (T-SOD), and total antioxidant capacity (T-AOC) in hepatopancreas, the changes in tissue structure, and the expression of related heat shock protein genes were measured. Results showed that the branchial structures of the three stress groups were damaged to varying degrees. In Group A, the AKP and ACP levels increased initially and then decreased, while the T-SOD levels decreased initially and then steadily increased. In Group B and Group C, the four enzymes showed similar trends. The expression levels of the Hsp10, Hsp60, and Hsp90 genes showed a similar trend, the maximum expression levels of the four genes were all at 96 h. By studying the stress responses of P. monodon to high temperature and low salinity, we have gained a deeper understanding of the physiological responses to environmental stressors, which will be useful in the development of protective measures for shrimps exposed to these stressors under aquaculture conditions.