A NEW SPECIES OF THE GENUS TRIC HOST RON GLUS FROM THE SMALL INTESTINE OF BHARAL (RHABDITIDA, STRONGYLATA: TRICHOSTRONGYLIDAE)

This paper reports a new species of Nematode (Trichostrongylidae) collected from the small intestine of bharal (Pseudois nayaur) and a brief description of its characteristics is given as follows:Trichostrongylus qilianensis sp. nov(figs. 1-8)Body small, slender, pale yellow when alive. Cuticle with very fine transverse striae. Mouth small surrounded by three lips. Buccal cavity indistinct, cervical papillae devoid. Prebursal papillae present. Nerve ring about 0.092(0.082-0.102) mm to the anterior end. Excretory pore situated at a depression in cuticle which is 0.144(0.138-0.158) mm from the anterior end. Simple esophagus 0.871(0.816-0.947) mm long.Male: Body 5.837(5.382-6.618) mm long with a width of 0.097(0.082-0.115) mm at the base of caudal bursa. The features of the bum and the arrangement of its rays coincide with the characteristics of the genus Trichostrongylus. Dorsal ray 0.051(0.043-0.056) mm long and bifurcated in the middle into two branches, each of which gives rise to an inner-lateral branch and further subdivided into two terminal twigs, the external twigs with a small papilla-like structure, Spicules equal in length, similar in shape, with a melon seed shaped depression at the middle, measuring 0.130(0.122-0.135) mm long and 0.021(0.020-0.023) mm wide. Each spicule gives rise to a small branch 0.013(0.010-0.016) mm long, 0.054(0.049-0.056) mm from the distal end, and each main branch with two barbs near the distal end. The upper barb large, situated at a distance of 0.022(0.020-0.023) mm from the distal end of the spicule and the lower one small, being 0.0066 mm from the distal end. Gubernaculum spindle-shaped, 0.064(0.053-0.069) mm long and 0.024(0.020-0.026) mm wide.Female: Body 6,329(5.516-6.968) mm long by 0.079(0.066-0.105) mm wide at the vulvar position. Ovijector including the sphincters 0.392(0.346-0.0445) mm long. Vulva round-shaped, 1.290(1.129-1.613) mm to posterior end. Anus 0.080(0.076-0.089) mm to the tail end.Discussion: Up to the present, there are altogether 39 species under this genus Trichostron-gylus reported from all over the world. The dorsal ray in the new species differs from 39 species of this genus. Dorsal ray is bifurcated in the middle into two branches, each of which gives rise to an inner-lateral branch and further subdivided into two terminal twigs, the external twigs with a small papilla-like structure. The spicules in the new species resemble 7ri-chostrongylus cervarius, but differ clearly from the latter mainly in the fallowing characteristics: the spicules with melon seed shaped depression in the middle; each spicule with two barbs near the distal end in lateral view, but indistinct in dorso-ventral view.Locality: Qilian County (38°10'N, 100°12'E), Qinghai Province, China.Holotype ♂, allotype ♀, paratypes 6 ♂♂, 4 ♀♀ are deposited in the Qinghai College of Animal Husbandry and Veterinary Medicine, Xining.