PROBLEM TO BE SOLVED: To provide a method for culturing Crysophrys major, and to obtain a feed for culturing the Crysophrys major and an agent for improving the body color of the Crysophrys major, which can control or prevent the browning or blackening of the body color of the Crysophrys major due to the deposition of malamine pigments and enable the production of the Crysophrys major having a clearly and beautifully red color body similar to the body color of natural Crysophrys major. SOLUTION: This method for culturing the Crysophrys major is characterized by feeding at least one additive selected from (a) grape seeds or a grape seed extract, (b) Psidium guajave leaves or a Psidium guajava leaf extract, and (c) a soybean isoflavone or an isoflavone-containing soybean product, or at least one additive selected from the above-mentioned (a) to (c) and astaxantin. The feed for culturing the Crysophrys major or the agent for improving the body color of the Crysophrys major is characterized by containing at least one additive selected from the above-mentioned (a) to (c) or at least one additive selected from the above-mentioned (a) to (c) and the astaxanthin.