Document Type : Research Paper
The present study aimed to study the histological structure of digestive tract of sea cucumber Holothuria arenicola collected from three regions in the coasts of Hormozgan including Bandar Lengeh, Qushm and Hormoz. All Samples were fixed in 10% formalin. The samples were processed through routine paraffin embedding technique, cut at 6 µm and stained with hematoxylin and eosin to study using light microscope. The results showed the esophagus consisted of striated squamous epithelium and underlying properia-submucusa and surrounded by two circular and longitudinal muscular layers. Stomach was coated by simple columnar epithelium with no stomach glands. The simple columnar epithelium with goblet cells coated all over the intestine. The posterior intestine joins the short wide cloaca in the posterior end of the body. The cloaca is attached to the surrounding body wall by an abundance of threadlike radial cloacal dilator muscles.