Effects of dietary supplementation with black chokeberry (Aronia melanocarpa) polyphenols on the growth, antioxidant capacity and immunity of Chinese mitten crabs (Eriocheir sinensis)

Polyphenols are abundant in black chokeberry, possess high biological activities, are widely used in food supplements and healthcare products, and have potential applications as aquatic feed additives. Our current study explored the effects of black chokeberry polyphenols (BPs) supplementation (0, 2, and 5 g/kg) in feed on the growth performance, body composition, antioxidant capacity and immunity of juvenile Chinese mitten crabs (Eriocheir sinensis, weight: 10 ± 1 g). The results showed that BPs addition to the feed did not influence the growth performance and body components of crabs, but significantly enhanced the antioxidant capacity in terms of total antioxidant capacity, superoxide dismutase, glutathione, and catalase activities. Furthermore, immunity was improved with respect to serum biochemical indicators (Total protein, albumin, and globulin) and enzyme activities (Alkaline phosphatase, acid phosphatase, and lysozyme). Antioxidant and immune-related gene expression (CncC, Keap1, Toll2, Dorsal, crustin-1 and peroxynectin) also confirmed the positive effects of BPs supplementation. Overall, the optimum dose of BPs in the feed was 2 g/kg. These findings could facilitate the industrial application of BPs in aquatic feed additives and contribute significantly to the development of healthy aquaculture.