The activity of digestive enzymes was determined in Hypophthalmichthys molitrix, Catla catla and Cyprinus carpio fed
with different feed ingredients. There were two glass aquaria (3×2×2 ft) for each species and ten fish in each
aquarium. Fish in one aquarium were fed on rice polish and fish in second aquarium were fed on corn gluten @ 3 %
of their wet biomass for 70 days. Results showed that fish wet weight varied significantly between the rice polish and
corn gluten fed fishes. The corn gluten fed fish showed significantly better growth performance than fish fed with rice
polish. The activity of amylase and lipase was higher in all fish species fed with corn gluten. Liver showed higher
amylase activity than the intestine, while the activity of lipase was higher in intestine. It was concluded that different
fish species respond differently to various feed ingredients. Therefore it is important to follow the acceptability and
digestibility standards during the selection of ingredients and for preparation of feed for different fish species.