Fatemeh Ebrahimi Moghadam - Department of Biology, Faculty of Sciences, Giulan University, Giulan
Mohamad Haseli - Department of Biology, Faculty of Sciences, Giulan University, Giulan

After examining the intestine of the shark species Mustelus mosis from the Persian Gulf, a new cestode species belonging to the genus Orygmatobothrium was discovered, which is morphologically completely different from its congeners. Since the body surface of all the cestode species is covered with small projections called microtriches and that this structures are taxonomically important and can only be studied using scanning electron microscopy, the microtriches of Orygmatobothrium n. sp. was examined in the present study. This species possesses a scolex with four bothridia, each of which has an anterior and a central sucker. The four bothridia are connected to the cephalic peduncle, from the posterior of which there are respectively the germinative zone and strobila. Both suckers are covered with acicular filitriches. The distal and proximal bothridial surfaces are covered respectively with the gongylate columnar spinitriches interspersed with the acicular filitriches and the trifid spinitriches. The cephalic peduncle is covered with the gladiate spinitriches and on the surface of the germinative zone and the entire strobila, there are the scutes formed by densely packed acicular filitriches. It is for the first time that the surface ultrastructure of a species of the genus Orygmatobothrium is studied at the level of the Indian Ocean

Microtriches, Cestoda, Orygmatobothrium,Persian Gulf