The digestive system of Trichomycterus brasiliensis (Lütken, 1874), a small sized tropical Teleostean fish widely distributed in South America, was studied. Tissue samples were prepared for light and scanning electron microscopy (SEM). Trichomycterus brasiliensis shows stratified esophagus epithelium with taste buds and goblet cells with neutral and acid mucus at the anterior region. The stomach is caecal, presenting a pyloric valve with neutral mucus cells. At the terminal portion it is surrounded by a thick muscular wall. The intestine shows two loops; the epithelium is single columnar, with acid and neutral mucus in goblet cells. Multicellular intestinal glands are absent. Granular cells are often seen in the mucosa, less in the submucosa but were not observed in the muscularis. After the intestine-rectal valve, the rectum shows lower mucosal folds, more goblet cells and a thicker muscularis. No lobes were observed at the liver. Small regions of pancreatic tissue may be identified within the hepatic tissue mainly surrounding vessels and ducts. A compact pancreas may also be observed ventrally to the stomach and covering the bile duct. The possible significance of the heterogeneous character of the digestive tube mucosubstances is discussed. The digestive system of T. brasiliensis presents structural characteristics of a predator fish.
Teleostei; digestive tube; histology