STRUCTURAL VARIATION IN GENITAL EPITHELIUM OF MALE HAEMONCHUS CONTORTUS (NEMATODA)

The male reproductive system of Haemonchus contortus consists of a single set of organs including along tubular testis, a dilated seminal vesicle and a glandular vas deferens are opening into the cloacal region, along with the rectum. The telegonic testis, consisting of a short apical germinal zone and a large growth zone, is bounded by a thin layer of epithelium. The seminal vesicle is set off from the testis by a marked change in its bounding epithelium which undergoes a pronounced increase in thickness and at its posterior end, it communicates with the vas deferens by a small obliquely placed tube. In its initial region, the vas deferens is bounded by a unique epithelium and subsequently, it becomes glandular in appearance. In the cloacal region, some accessory copulatory structures i.e. a pair of spicules and a single median gubernaculum are also associated with the male reproductive system.