title: Haemonchus horaki n. sp. (Nematoda: Trichostrongyloidea) from the grey rhebuck Pelea capreolus in South Africa.
abstract: In the course of a revision of species of Haemonchus Cobb, 1898 (Nematoda), commonly referred to as large stomach worms and significant pathogens of ruminants, a new species was discovered in the grey rhebuck Pelea capreolus, and the bontebok Damaliscus pygarthus, in South Africa. The new species, Haemonchus horaki, was previously reported as a long-spicule form of H. contortus (Rudolphi, 1803) Ransom, 1911. The new species, compared with H. contortus, can be distinguished by significantly longer spicules (555-615 microm vs. 383-475 microm); a synlophe with fewer ridges (26 vs. 30 in the region of the posterior part of the esophagus) that extend more posteriorly (within 1 mm of the copulatory bursa in males and postvulvar in females, vs. 2/3 to 3/4 of prebursal and prevulvar lengths); and an asymmetrical dorsal lobe with a long dorsal ray divided for more than half of its length, forming 2 branches of unequal length (vs. a dorsal ray divided for less than half of its length and forming 2 equal branches in H. contortus).
authors.affiliation: Parasite Biology, Epidemiology and Systematics Laboratory, Agricultural Research Service, U.S. Department of Agriculture, The Henry A. Wallace Beltsville Agricultural Research Center, Maryland 20705-2350, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Lichtenfels
authors.forename: P A
authors.initials: PA
authors.lastname: Pilitt
authors.forename: L M
authors.initials: LM
authors.lastname: Gibbons
authors.forename: J D
authors.initials: JD
authors.lastname: Boomker
mesh_terms: D000818:Animals; D000866:Antelopes / Q000469:parasitology*; D005260:Female; D006188:Haemonchiasis / Q000469:parasitology / Q000662:veterinary*; D006189:Haemonchus / Q000033:anatomy & histology / Q000145:classification*; D006651:Histocytochemistry; D008297:Male; D008857:Microscopy, Interference; D013019:South Africa