Climate change and intensified human activities have accelerated the salinization and alkalinization of aquatic environments, further shrinking the space for freshwater aquaculture. One of the key survival mechanisms for fish in saline-alkaline habitats is the conversion of accumulated endogenous ammonia into less toxic glutamine. This study focuses on the freshwater teleost, crucian carp (Carassius auratus), using the liver as the target organ. Three groups were established: 0, 20, and 40 mmol/L NaHCO