Cyprinus carpio, Parabramis pekinensis, Aristichthys nobilis, and Lateolabrax maculatus were systematically evaluated as crucial components of Chinese aquaculture with substantial market demand. Texture profile analysis (TPA) showed C. carpio had maximal hardness, while L. maculatus displayed optimal elasticity. Nutrient composition analysis revealed that the highest crude protein content was identified in L. maculatus, while a higher crude lipid level was recorded in C. carpio. Fatty acid profiling established L. maculatus as a superior source of monounsaturated fatty acids (MUFAs), whereas P. pekinensis was distinguished by its polyunsaturated fatty acid (PUFA) content. Volatile compounds were comprehensively analyzed using an electronic nose (e-nose) coupled with HS-SPME-GC-MS, resulting in the identification of 59 flavor compounds. Molecular docking demonstrated that hydrogen bonding and π–π stacking were identified as critical mechanisms governing flavor perception. These findings offer valuable information that can support improvements in aquaculture management practices and help inform consumer choices regarding fish quality.

The Xingkai Lake topmouth culter (Culter alburnus) is an endemic, economically valuable fish in Heilongjiang that is highly sensitive to ammonia. However, the systemic effects of acute ammonia stress on its liver have not been determined. The objective of this study was to elucidate the changes in and relationships among stress biomarkers, antioxidant defense mechanisms, apoptosis indicators, and histopathological alterations in the liver of C. alburnus, a fish species native to Xingkai Lake, China, under acute ammonia exposure. Guided by the findings of a 96 h-LC₅₀ assay, the researchers subjected the fish to 48 h of acute exposure at specified total ammonia nitrogen (TAN) concentrations of 30 mg/L, 36 mg/L, and 40 mg/L. A comprehensive assessment of physiological and biochemical markers, including cortisol (COR), blood ammonia (Amm), blood glucose (Glu), aspartate aminotransaminase (AST), alanine aminotransaminase (ALT), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA), revealed pronounced physiological stress and oxidative damage, particularly in the high-concentration groups. The physiological effects of ammonia exposure on C. alburnus showed a clear concentration and time dependence. Notably, elevated ammonia levels significantly upregulated apoptosis-associated genes such as P53, Bax, and Caspase-3. These findings were further substantiated by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assays and histopathological examinations. Overall, the study demonstrated that acute ammonia exposure exerted substantial impacts on the physiological, biochemical, and genetic expression profiles of C. alburnus in Xingkai Lake, leading to sustained stress and oxidative damage, especially at elevated concentrations (30–40 mg/L).