Comparative morphology, anatomy and histology of the alimentary canal of an Indian freshwater major carp, Labeo calbasu (Hamilton) during the different life-history stages in relation to food and feeding habits.

1. The early life-history stages of Labeo calcasu (Hamilton) viz., the fries, are zooplankton-feeders (carnivorous). The morphology, anatomy and histology of the alimentary canal during this stage is adapted accordingly. 2. With increase in age, size and body-length, the food and feeding habits of the fish undergo changes from the carnivorous to the herbivorous type (adult) through the omnivorous type (fingerlung). 3. The morphology, anatomy and histology of the alimentary canal gets modified accordingly in the fingerlings and adults.