The effects of salinities stress on histopathological changes, serum biochemical index, non-specific immune and transcriptome analysis in red swamp crayfish Procambarus clarkii

This study aimed to investigate whether different salinity stresses (0, 2, 4, 6, or 8 ppt NaCl) affect the histoarchitecture, serum biochemical indices, antioxidant responses, and transcriptome analysis of the red swamp crayfish Procambarus clarkii. Transmission electron microscopy results showed that the degree of damage to the nuclei and mitochondria in the hepatopancreas increased with increasing salinity. Scanning electron microscopy results showed that the degree of gill wrinkles was enhanced under salinity stress. Serum biochemical indices demonstrated that the cholesterol significantly decreased while the triglyceride, aspartate transaminase, and alanine transaminase contents significantly increased with increasing salinity. The antioxidant parameters, including catalase, total antioxidant capacity, and glutathione peroxidase, significantly decreased, while the malondialdehyde content significantly increased under salinity stress. Transcriptome analysis revealed that the expression pattern of immune-related genes showed a downward trend. These findings enrich our knowledge about the salinity stress response of farmed organisms and provide a theoretical base for salinity domestication and saline soil cultivation of P. clarkii, which might contribute to income improvement, employment generation, food security, and environmental safety.