Effects of overwintering on proximate composition, fatty acid composition, serum parameters, antioxidant status, and lipid metabolism in <i>Onychostoma macrolepis</i>

To investigate the metabolic adaptation and lipid utilization to overwintering in Onychostoma macrolepis (27.05 ± 1.79 g), fish were sampled at 0, 75, 150 days, respectively. Fish randomly reared into three outdoor tanks (water temperature range:0–10°C). After overwintering, body weight, viscera index, hepatopancreas intraperitoneal fat index significantly lower than before (p < 0.05). In liver, contents of monounsaturated fatty acid polyunsaturated (PUFA) observed be lowest highest after days respectively serum, concentrations triglyceride (TG) total cholesterol decreased while activities alanine aminotransferase aspartate increased Day 75 Hepatic antioxidant whereas malondialdehyde content was higher Serum indexes similar those liver. During decrease TG tissues influenced by upregulation lipidolysis genes. These results indicate that lipids continuously mobilized as physiological fuels throughout overwintering. Overwintering could result poor status peroxidation level O. macrolepis.