Effect of Live, Frozen and Artificial Feeds on Digestive Enzymes, Aminotransferase, Histology of Liver and Intestine in Mandarin Fish Hybrid (Siniperca chuatsi ♀ x Siniperca scherzeri♂)

To partially or entirely replace the use of live foods for mandarin fish (Siniperca chuatsi female x Siniperca scherzeri male) with frozen or artificial feeds, a detailed understanding of their digestive physiology and the influence of these replacements is needed. The experiment was conducted in a recirculation system for 10 weeks. At termination of the feeding trial, protease activity in the alimentary tract and aspartate aminotransferase (AST) in the livers of fish fed frozen feed were significantly higher than those fed artificial feeds. Fish fed artificial feed had the highest AST and alanine aminotransferase (ALT) serum activity in serum which suggests that the liver was damaged to some extent. These results were further confirmed by histology of the liver. Fish fed the artificial feed had serious hepatocyte vacuolization and disorganization. The mucosal epithelium of intestine in fish fed frozen and artificial feed had poorly developed enterocytes with a shortening of the microvilli, decreased absorptive vacuoles and hyperplasia of the lamina propia. n In addition to tissue damage there was a reduction in the ability of fish to digest frozen and artificial feed. The results of this study indicate that the mandarin fish hybrid readily feeds on frozen and artificial feeds. However, a more appropriate artificial feed for this species is needed to improve the digestive function and histology of the digestive tract.