Histological and histochemical study of digestive tube in Acipencer persicus larvae until 2weeks post hatching

Acipenser persicus is ponto–caspian endemic species and primarily in the eastern of the south caspian. Acipenser persicus has become the most popular sturgeon in aquaculture due to its good rearing characteristics so the histopathologic and histochemical study of gastrointestinal tract in order to use some methods for proper feeding and prevating of toxic materials on larva، can be used to produce more valuable product with much lower cost in a short time. Methods and material: This study was carried out on Acipenser persicus at the age of 1-14 days post hatching (dph). Histochemical and histological studies for observation of yolk sac resorption process، and the changes of digestive system were done d with HE، (PAS) and alsian blue (AB) pH2. 5 pH1 staining. In fishes digestive tube is undifferentiated simple tube and filled with yolk platelets. On 7dph، stomach differentiate into glandular and non glandular portion. In this study، stomach increased in size and the glandular portion had positive PAS and negative AB reaction. The stomach of 14 day old larvae shows the columnar epithelium cells that probably the presence of mucous substances stained strongly with PAS. The intestine was identified with a layer of columnar epithelial cells on day 1 after hatching. The melanin plug was disappeard from the lumen of the spiral intestine on day 12. Goblet cells were interspersed among the columnar epithelial cells. Because of mucosubstances presence in goblet cells thay had very strongly reaction with PAS and AB staining.