The feeding preference of the mandarin fish, Siniperca chuatsi, for live bait fish over pellet feed increases the costs and risks of breeding. Animal feeding behavior is directly or indirectly influenced by intestinal flora and innate immunity. Probiotics have been shown to regulate intestinal flora and stimulate innate immunity in a variety of species. In this study, during the pellet-feed feeding process of mandarin fish, Bdellovibrio bacteriovorus at a concentration of 10⁸ PFU (plaque forming unit)/mL was added to the water body for 6 weeks, and the effects on the survival, growth, appetite, intestinal flora, innate immunity, antioxidant capacity, and intestinal histology of mandarin fish were studied. The results showed that addition of B. bacteriovorus at a concentration of 10⁸ PFU/mL to aquaculture water could significantly promote mandarin fish pellet-feed feeding, improve the survival rate and growth performance of mandarin fish that were fed pellet feed. Compared with the control group, addition of B. bacteriovorus promoted the expression of appetite-regulating genes nerve peptide Y (Npy) and agouti gene-related protein (Agrp). Intestinal microflora analysis and intestinal histological analysis results revealed that B. bacteriovorus reduce the abundance of pathogenic bacteria Aeromonas in the intestinal flora, reduce damage to the intestinal mucosa and epithelial cells, and increase the thickness of the intestinal basement membrane and height of intestinal villi. Similarly, an increase in the serum lysozyme and immunoglobulin M (IgM) contents was observed after B. bacteriovorus administration. Moreover, B. bacteriovorus improved the activity of antioxidant enzymes, reduced glutathione (GSH) and catalase (CAT). In general, addition of B. bacteriovorus at a concentration of 10⁸ PFU/mL to aquaculture water could significantly promote pellet-feed feeding of mandarin fish and improve the growth performance and survival rates of mandarin fish under pellet-feed feeding conditions. This promoting effect may be achieved by B. bacteriovorus stimulation of innate immunity and regulation of intestinal flora.

live鱼（Siniperca chuatsi）比活饵鱼的饲料偏爱颗粒饲料，这增加了养殖成本和繁殖风险。动物的喂养行为直接或间接地受到肠道菌群和先天免疫力的影响。益生菌已显示出可调节肠道菌群并刺激多种物种的先天免疫力。在这项研究中，在普通鱼的颗粒饲料喂养过程中，将浓度为10 ⁸ PFU（噬菌斑形成单位）/ mL的Bdellovibrio bacteriovorus添加到水体中6周，并对存活，生长，研究了fish的食欲，肠道菌群，先天免疫力，抗氧化能力和肠道组织学。结果表明，添加向养殖水中添加浓度为10 ⁸ PFU / mL的B.细菌能显着促进man鱼颗粒饲料的投喂，提高了pellet鱼饲料颗粒饲料的成活率和生长性能。与对照组相比，添加细菌芽孢杆菌可促进食欲调节基因神经肽Y（Npy）和刺骨相关基因蛋白（Agrp）的表达。肠道菌群分析和肠道组织学分析结果表明，细菌杆菌降低了致病菌气单胞菌的丰度在肠道菌群中，减少对肠粘膜和上皮细胞的损害，并增加肠基底膜的厚度和肠绒毛的高度。类似地，在施用细菌杆菌后，观察到血清溶菌酶和免疫球蛋白M（IgM）含量增加。此外，细菌弧菌改善了抗氧化酶的活性，减少了谷胱甘肽（GSH）和过氧化氢酶（CAT）。通常，以10 ⁸的浓度添加细菌芽孢杆菌在养殖水体中加入PFU / mL可以显着促进pellet鱼的颗粒饲料喂养，并提高pellet饲料条件下man鱼的生长性能和成活率。这种促进作用可以通过细菌芽孢杆菌对先天免疫的刺激和肠道菌群的调节来实现。