UTILIZATION OF DISACCHARIDES BY JUVENILE TILAPIA, OREOCHROMIS-NILOTICUS X OREOCHROMIS-AUREUS

juvenile tilapia were fed isonitrogenous diets containing 44% maltose, sucrose, lactose, glucose or starch for 8 weeks. Average initial body weight of the fish was 0.80 +/- 0.05 g. Each diet was fed to 3 groups of 19 fish/aquarium in a recirculating, double-filtered rearing syste m. Results indicated that weight gain of fish fed the different carboh ydrates were starch > maltose > sucrose > lactose > glucose. The diffe rences between each group were significant (P < 0.05). Body lipid cont ent was highest in fish fed the starch diet, followed by those fed the maltose and sucrose diets, then the lactose diet, and was lowest in f ish fed the glucose diet. Intestinal disaccharidase activities in tila pia were not affected by the carbohydrates ingested. Plasma glucose co ncentrations were similar in fish fed the disaccharide and starch diet s and were lower than those in fish fed the glucose diet. The data sug gest that tilapia utilizes disaccharides better than glucose but more poorly than starch. Of the disaccharides, maltose was better utilized, followed by sucrose and lactose.