a histochemical of developing digestive tract of persian sturgeon (a. persicus) from hatching to fingerling

histological development of digestive tract of the persian sturgeon (acipenser persicus) from hatching to fingerling size was studied using light microscope. the digestive tract of newly hatched larvae was a simple tube which continued from mouth to anus. in 7 days post hatching, digestive tract became differentiated and secretion was started smoothly, with appearance of goblet cells in epithelium of the mouth, pharynx and esophagus. in this stage, a thin layer of neutral mucopolysacharid component covered the epithelium of digestive tract. nine days post hatching (exogenous feeding), this canal became differentiated into mouth, pharynx, esophagus, glandular and non-glandular stomach, anterior and posterior parts of the intestine, similar to adults at the onset of exogenous feeding, goblet cells appeared at intermediate and specially posterior part of the intestine and secretion role in this cells started that increased gradually. present results reveal that the ontogenetic development of the digestive tract of persian sturgeon is similar to acipenserid species. however, there exist differences referred to the differentiation time of some digestive structures, such as the differentiation of taste bud, present of mouth and esophagus which affect first feeding time.