The present study was done in order to demonstrate the histological, histochemical as well as surface architecture
of the posterior intestine of grass carp. The epithelium of posterior intestine was constituted of enterocytes (simple
columnar epithelium), goblet cells, enteroendocrine cells and lymphocytes. The enterocytes were characterized by
numerous large vesicles, which may represent pinocytotic activity to some nutrients. The goblet cells gave positive
reaction to both PAS and Alcian blue, in addition to presence of metachromatic substances by toluidine blue. The
lamina propria-sub mucosa was consisted of loose connective tissue with abundant collagen and elastic fibers.