Effects of sand substrate removal on the intestinal antioxidant and metabolism in Marsupenaeus japonicus.

ABSTRACT

M. japonicus is an important specie for factory farming, and factory farming requires an environment with sand at the bottom of the pond. However, the physiological responses as well as survival in the process of factory farming without laying sand are currently unknown. In the present study, we explored the effect of sand substrate removal on the intestinal histomorphology, antioxidant enzyme activity, and metabolic profile of M. japonicus. Our results indicate a gradual increase in the mortality rate of kuruma shrimp in ponds lacking sand substrate. The intestinal mucosa exhibited necrosis and the presence of vacuoles, with their number gradually increasing over time. The intestinal villi showed significant erosion, accompanied by a decrease in intestinal superoxide dismutase (SOD) activity and catalase (CAT) activity, and consistent with an upregulation in the expression of apoptosis-related genes such as caspase-3, indicating an adaptive response to the adverse environmental conditions. Additionally, the metabolomic analysis revealed that most significantly differential metabolites were linked to amino acid and lipid metabolism. These findings enhance our understanding of the sand substrate removal on the intestinal health of kuruma shrimp, which provides a basis for the factory farming.