COMPARATIVE ANATOMICAL AND HISTOLOGICAL STUDY OF SOME ORGANS IN TWO FISH SPECIES CYPRINUS CARPIO LINNAEUS, 1758 AND MESOPOTAMICHTHYS SHARPEYI (GÜNTHER, 1874)(CYPRINIFORMES, CYPRINIDAE)
The present study aims to give some details about the normal anatomical and histological structure of the liver, pancreas and gall bladder in Cyprinus carpio Linnaeus, 1758 and Mesopotamichthys sharpeyi (Günther, 1874). Anatomical results revealed that the liver of C. carpio is a reddish-brown in color, located in the anterior part of abdominal cavity and dispersed between most of the intestines, which is divided into two lobes; while in M. sharpeyi the liver is light brown in color located in the anterior part of abdominal cavity and extends to the end of the intestinal tract with two lobs. The gallbladder situated in the right side of the liver in both species. Histological results in both species showed that the liver consists of hepatocytes arranged radially around a central vein, separated by blood sinusoids, not divided into distinct hexagonal lobules, no portal traids as in higher vertebrates. The wall of gallbladder consist of three distinct layers: Tunica mucosa, tunica muscularis and tunica serosa. Microscopic results showed that exocrine pancreatic tissue was diffused type in both species located in liver and consists of acini as "hepatopancreas ", however, pancreatic tissue diffused between the intestinal coiling in C. carpio, and in the internal surface of the liver in M. sharpeyi. Endocrine parts of pancreas were observed in few numbers of cell masses in various sizes among exocrine pancreatic cells.