Haemonchus horaki n. sp (Nematoda : Trichostrongyloidea) from the grey rhebuck Pelea capreolus in South Africa

In the course of a revision of species of Haemonchus Cobb, 1898 (Nematoda), commonly referred to as large stomach worms and significant pathogens of r uminants, a new species was discovered in the grey rhebuck Pelea capreolus, and the bontebok Damaliscus pygarthus, in South Africa. The new species, H aemonchus horaki, was previously reported as a long-spicule form of H. cont ortus (Rudolphi, 1803) Ransom, 1911. The new species, compared with H. cont ortus, can be distinguished by significantly longer spicules (555-615 mum v s. 383-475 mum); a synlophe with fewer ridges (26 vs. 30 in the region of t he 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 wit h a long dorsal ray divided for more than half of its length, forming 2 bra nches of unequal length (vs. a dorsal ray divided for less than half of its length and forming 2 equal branches in H. contortus).