Description of fungivorous phase of Hexatylus viviparus Goodey, 1926 (Neotylenchidae, Tylenchina) from potato field in Chaldoran, West Azarbaijan province, Iran

The genus Hexatylus Goodey, 1926 belonging to the family Neotylenchidae is distinguished from other members of the family with cephalic framework with eight sectors, the presence of strengthening rings around stylet, forked stylet at base, dorsal gland orifice near the base of stylet, lumen of esophagus joins lumen of intestine in region of nerve ring, esophagus glands overlap intestine dorsally, mono prodelphic gonad in females, vulva as a transverse slit, close to anus, genital branch without post vulval sac, tail short, with sharp end and pointed tip. Goodey (1926) reported Hexatylus viviparus associated with diseased potato tubers in England. The nematode is spread worldwide and there are reports of this species in Europe, Asia and America. A population of this species was collected from the soils of Chaldoran, West Azarbaijan province and the nematodes were extracted using combined sieving and centrifuge method and after killing, fixing, transferred to anhydrous glycerin. They were mounted on microscopic slides and the morphological and morphometrical characters studied using an Olympus AX70 optical microscope and digital images prepared by a connected camera to the microscope.