Functional morpho-histology of the alimentary canal of an Indian frewhwater major carp, Labeo rohita (Hamilton) during it's different life-history stages.
1. The alimentary canal of the fry of L. rohita (Hamilton) is of the carnivorous type in nature and disposition with a low relative length of the gut (R. L. G.). 2. End-buds are present. The buccopharyngeal region has a simple epithelial surface. Mucous cells are small and few throughout the length of the alimentary canal. The presence of these structures in association with a zooplankton feeding habit indicate that the fries are primarily sightfeeders and carnivorous. 3. With increase in age and body-length, the food and feeding habits of the fish undergo changes and accordingly the fingerlings and adults become herbivorous. The value of the R. L. G. steadily increases and the alimentary canal gradually develops into the typically herbivorous type. 4. Tast buds by now become completely developed and have lamina propria, sustentacular cells, neuroepithelial cells, gustatory pores and gustatory canals. 5. Taste buds are abundant in the lip, buccopharynx and anterior oesophagus. The buccopharyngeal region is also provided with distinct villi. Mucous cells are abundant and large being present throughout the alimentary canal. 6. The frequency, length, breadth and distribution of the mucous cells and taste buds are significantly different in marked contrast with those of the fry thus indicating that the fingerlings and adults depend primarily on their gustatory organs for feeding. The fingerlings and adults therefore, are herbivorous and tast feeders.
D000818:Animals; D002347:Carps / Q000033:anatomy & histology* / Q000254:growth & development; D003530:Cyprinidae / Q000033:anatomy & histology*; D004064:Digestive System / Q000033:anatomy & histology* / Q000254:growth & development; D005247:Feeding Behavior; D008099:Liver / Q000033:anatomy & histology; D009092:Mucous Membrane; D010179:Pancreas / Q000033:anatomy & histology; D013650:Taste Buds / Q000033:anatomy & histology