To examine the effects of corn gluten meal on lysozyme activity and c-lysozyme gene expression in Fugu obscurus,the fish were fed with diets containing 0%,5%,10%,15% and 20% corn gluten meal in replacement of 0%,7.4%,14.8%,22.2% and 29.6% of conventional fish meal for 60 days,respectively.Lysozyme activities and mRNA levels in the hepatopancreas,head kidney and spleen were examined.The results show that:(1) At the beginning of the experiment,the lysozyme activities of the hepatopancreas,head kidney and spleen were 9.14 U/mg protein,42.12 U/mg protein and 40.49 U/mg protein,respectively.The c-lysozyme mRNA relative expression levels of head kidney and spleen were 3.76 and 3.24 times of the hepatopancreas.(2) Different amounts of corn gluten meal in the diets exerted different effects on the lysozyme activities.The lysozyme activities of hepatopancreas in the 15% and 20% trial groups were significantly lower than that of the control group,and they significantly increased in the 5% and 10% trial groups.In the head kidney,lysozyme activities were significantly enhanced in the 10% trial group,but they significantly reduced in the 15% and 20% trial groups.In the spleen,there were not significant changes on the enzyme activities in the 5% and 10% trial groups,but in the 15% and 20% trial groups,the enzyme activities significantly reduced.(3) Different amounts of corn gluten meals in the diets also resulted in significant changes in c-lysozyme mRNA levels in tissues.In comparison with the control group,the c-lysozyme mRNA expression levels of hepatopancreas significantly reduced in the 15% and 20% trial groups,although they significantly increased in the 5% and 10% trial groups.In the spleen,there were not significant changes on the c-lysozyme mRNA expression levels in the 5% and 10% trial group,but they were significantly lower in the 15% and 20% trial groups than that of the control group.In the head kidney, c-lysozyme mRNA expression levels were significantly enhanced in the 10% trial group,but they significantly reduced in the 15% and 20% trial groups.In a word,the enzyme activities and c-lysozyme mRNA expression levels were peaked in the 10% corn gluten meal group.