Histological Description of intestine and Gut Associated Lymphoid Tissue in Esox Lucius from Anzali wetland

Study of gut tissue structure in fish is important as the fish culture increases and then, more information is required regarding to feeding and nourishment. Then, the present study aimed to describe the histological and histochemical characteristics of GALT in the pike, Esox lucius, from the Anzali wetland. In this regards, 20 E. lucius were collected from the Anzali wetland. Tissue samples from different parts of gut were fixed in Bouin’s solution. Tissue slides were prepared using tissue preparation techniques and stained with hematoxylin and eosin (H&E), Periodic acid–Schiff (PAS), Alcian blue and AB-PAS. In E. lucius the internal surface of gut was folded and coated by simple columnar cells and goblet cells. Goblet cells positively reacted to PAS, AB and AB-PAS, due to mix acidic and neutral glycoproteins containing. Eosinophilic granular cells were detected in lamina propria. GALT represented throughout the gut mucosa in the epithelium and lamina propria. Lymphocytes increased in number toward the posterior part of intestine (P<0.05).