The liver of Cat fish and Nile telapia were surrounded by a thin fibroconnective tissue capsule contained reticular and collagen fibres, this connective tissue investment covered by a single layer of mesothelial cells. The capsule was thickened at hilus. The parenchyma of liver in both types was not divided into distinct lobules. Typical portal triads were not obvious. The portal area was composed either of hepatic artery or portal vein with bile duct. The hepatocytes of both types
contain PAS positive materials, glycogen granules, lipids and pigment granules. In Cat fish, the argyrophilic reticular fibres form a meshwork supporting the hepatocytes and were demonstrated in the wall of blood vessels and around acini of exocrine pancreas, but in Nile telapia it was restricted in the capsule, which sent fine fibres in-between hepatocytes underlying it, in the wall of blood vessels and around the pancreatic acini. Fat cells and melanomacrophage cells were also demonstrated within the parenchyma of Cat fish. Exocrine pancreatic tissues were highly distributed in the parenchyma of liver in Nile telapia surrounding nearly all branches of hepatic portal veins, but in Cat fish, these tissues were associated only with large branches of portal vein