Effects of Dietary Cholesterol Levels on the Growth, Molt Performance, and Immunity of Juvenile Swimming Crab, Portunus trituberculatus

The effects of dietary cholesterol levels on growth, molt performance, and immunity of juvenile swimming crab Portunus trituberculatus, were investigated at four cholesterol levels (0.2%-1.4%) of purified diets. Each diet was fed in triplicate to 18 crabs per replicate for 50 days. Crabs fed the diet with 1.0% cholesterol showed significantly higher (P<0.05) specific growth rate (SGR) than the other groups, who suffered from relatively lower molt death syndrome (MDS). Cholesterol content in the serum, whole body, and hepatopancreas increased in relation to dietary cholesterol. Muscle lipid content was significantly higher (P<0.05) in crabs fed the diet with 0.2% cholesterol compared to the other treatments. Crabs fed moderate dietary cholesterol levels showed higher alkaline phosphatase (AKP) or acid phosphatase (ACP) levels than those fed 0.2% or 1.4% cholesterol diets. The present study also showed that dietary cholesterol supplementation generally increased serum superoxide dismutase (SOD) activity. Overall, moderate dietary cholesterol (1.0 %) enhanced the performance of growth, survival, molting, and immunity of juvenile swimming crab P. trituberculatus.