SUITABLE SUGAR LEVEL IN BROWN FISH-MEAL DIET FOR TIGER PUFFER

Tiger puffer Takifugu rubripes, weighing about 10 g, were reared for 2 8 days on brown fish meal diets containing 10, 13, 16, 19, and 22% whi te dextrin. Except for a low survival (75%) obtained in the fish reare d on the lowest white dextrin diet, the fish reared on other diets and sandeel, as a reference, showed high survival (> 95%). Under a simila r daily ration size, the best weight gain, feed efficiency, and protei n efficiency ratio were commonly noted in the fish fed the 16% dextrin diet. No marked differences among the dietary treatments were found i n the proximate compositions of whole body and the hepatopancreas. App arent digestibilities of dietary carbohydrate and protein remained hig h in the fish given 13-16% and 10-19% dextrin diets, respectively, usi ng the intestinal digesta dissected at 5 h after feeding. These result s indicate that a suitable dietary dextrin level for the puffer is est imated around 16% and dietary carbohydrate content about 20%.