HISTOLOGY AND ULTRASTRUCTURE OF THE HEPATOPANCREAS OF THE TIGERFISH, HYDROCYNUS-FORSKAHLII

Study of the histology and ultrastructure of the hepatopancreas of the tigerfish, Hydrocynus forskahlii shows that the liver parenchyma is d ivided into irregularly shaped lobules, separated by the exocrine panc reas and associated connective tissue. The hepatocytes are arranged in interconnecting cords or laminae, two to three cell layers in thickne ss. Sinusoids separate the laminae. The spherical to oval-shaped hepat ocytes contain large, round, centrally situated nuclei with prominent nucleoli. The cytoplasm of the hepatocytes contains abundant rough and smooth endoplasmic reticulae, free polysomes, and mitochondria. Exocr ine pancreatic tissue is scattered throughout the liver. This tissue i s encapsulated by an endothelium resting on a thin layer of connective tissue and is separated from the liver parenchyma by a sinusoid. The nuclei of the exocrine pancreas cells are spherical, basally situated within the cells, and contain dark nucleoli. Vesicular rough endoplasm ic reticulae and secretory granules lie in the apical regions of the e xocrine pancreas cells. (C) 1996 Wiley-Liss, Inc.