LAUSR

Cold-anesthetization waterless live fish preservation is considered a promising alternative strategy. This work investigates the effects of temperature chilling rates of 2, 4, and 6 °C/h on serum biological parameters and muscular chemical composition of channel catfish Ictalurus punctatus and the influence of waterless preservation time (6, 9, 12, 15, and 18 h) on survival after subjection to three chilling rates. Fish subjected to increasing chilling rates showed lower survival and shorter preservation time. The research results revealed that a temperature gradient drop of 2 °C/h was conducive to maintaining the activity of creatinine (CREA), lactic dehydrogenase (LDH), and pyruvate kinase (PK). The serum aspartic transaminase (AST) and alanine transaminase (ALT) activity dramatically increased after anesthetization. Blood urea nitrogen (BUN) and CREA, whose activity is sensitive to hydropenic conditions, increased significantly after waterless preservation and showed a slight reversal after recovery. Anesthetization caused a significant decrease in protein and fat in muscle, while no obvious trend was observed among different chilling groups. Muscle glycogen (MG) and water-holding capacity (WHC) decreased after anesthetization, then increased after preservation for 12 h, and decreased again after recovery for 24 h. The muscle pH showed the opposite trend. It can be concluded that the whole process resulted in marked changes in the muscle chemical composition. The development of a new green method for anesthetization of live channel catfish for long-term waterless preservation in the present work helps to determine the physiological changes that occur during preservation, providing an effective reference for investigation in other freshwater fish.