In the present study, the bioconversion of the dietary ergosterol in the crab, Portunus trituberculatus, was investigated. After the supplementation of the diet containing 14C-ergosterol to the crabs, the sterols were isolated from the tissues of crabs. The isolated sterol was found to contain only cholesterol as a sterol and revealed relatively high radio-activity. In column chromatography on a silver nitrate-impregnated silicic acid as acetate, the 14C-cholesterol gave one radioactive peak corresponding to cholesteryl acetate. During the recrystallizations, the 14C-cholesteryl acetate showed the constant specific activity (dpm/mg).
These results indicated that the dietary ergosterol is bioconverted to cholesterol in the crab, Portunus trituberculatus.