On the morpho-histology of the alimentary tract in the Indian climbing perch, Anabas testudineus (Bloch), in relation to food and feeding habits.

Functional morpho-histology of the alimentary tract of the Indian Climbing perch, Anabas testudineus (BLOCH) has been described. The fish possesses a wide, slightly upturned mouth. The presence of jaw, vomerine, palatine, pharyngeal, and horny pad teeth in the bucco-pharyngeal region indicates the carnivorous feeding habit of the fish. Gill-rakers are toothed but the tongue is edentulous. The latter helps in manipulation of larger prey. The nature and disposition of the taste buds in the lips and bucco-pharyngeal region indicate that the fish procures its food primarily by taste and secondarily by sight. Taste buds are also present in the middle oesophagus which indicates that the gustatory sense extends upto this region. The surface epithelium of the cardiac stomach is conspicuous in having specific mucous cells. The pyloric stomach indicates a more primitive nature due to the presence of tubular mucous glands or pyloric glands. The number of pyloric caeca is 4. The intestine is slightly looped and the dimensionless RLG (Relative Length of the Gut) is 0.42. An ileo-rectal valve and the mucosal folds distinguish the rectum from the intestine.