Nutritional value of dietary cholesterol and other sterols to larval prawn, Penaeus japonicus Bate

Abstract

The nutritional value of 11 sterols to larval prawn, Penaeus japonicus, was examined using defined, artificial diets containing carrageenan as a binder. Growth and survival of the prawn larvae fed on a diet with 1.0% cholesterol, 6.0% pollack liver oil, and 3.0% soybean lecithin as lipid sources were similar to those of the control group receiving both Chaetoceros gracilis and Artemia salina nauplii. A sterol-free diet resulted in poor survival and slight retardation of larval development. These results show that the prawn larvae require dietary sources of cholesterol or other sterols as indispensable nutrients. Cholesterol had the highest dietary value among the sterols examined in terms of promoting growth and survival. Ergosterol and 24-methylenecholesterol had a similar dietary value to that of cholesterol. 24-Methylcholesta-5,22-dienol, isofucosterol, and 7-cholestenol also effectively supported growth, whereas stigmasterol, β-sitosterol, 22-dehydrocholesterol, fucosterol, and lanosterol promoted growth weakly or not at all. Isofucosterol, β-sitosterol, and 22-dehydrocholesterol increased the rate of survival of the prawn larvae slightly, but stigmasterol, fucosterol, 7-cholestenol, and lanosterol were ineffective. The results of the present study suggest that P. japonicus larvae are probably incapable of de novo sterol synthesis but may be able to dealkylate some C 28 and C 29 sterols to cholesterol, which is the most effective sterol.