The present work was carried out on 20 specimens of grass carp in order to observe the morphological features
of intestine. The present study showed that the intestine was long, which may help in retention of food for a longer
period of time to ensure proper digestion. Also, the percent of relative gut length (RGL) of grass carp was 1.92%.
This RGL with a large intestinal diameter of this species allowing increase the storage capacity of food. The intestine
of grass carp were divided into anterior, posterior intestine and rectum. There were no intestinal villi or multicellular
intestinal glands in any regions of intestine. The most important features of anterior intestine were a wide diameter
of the lumen and a great number and height of mucosal folds. The anterior intestine was lined by simple columnar
epithelium, intercalated with goblet cells, wandering lymphocytes and enteroendocrine cells. Scanning electron
microscopy, revealed presence of long wavy mucosal folds that formed of enterocytes covered with numerous
microvilli, intermingled with numerous openings for goblet cells.