The species Ophidascaris durissus sp. nov. is proposed with basis on specimens recovered from the rattlesnake Crotalus durissus L., 1758 (type host) captured in Foz do Iguaçu, Brazil (type locality). By the lack of interlabia, the new species can be compared only to O. natricis Yamaguti, 1935 from Japan and O. freitasi Hoa & Lien, 1970, from Vietnam. However, O. durissus sp. nov. differs from O. natricis mainly by the absence of internal lip papillae, location of the vulvar aperture and length of the spicules; from O. freitasi mostly by the greater number of pre-cloacal and distribution of post-cloacal papillae.
Brazil; Crotalus durissus; Nematoda; Ophidascars durissus sp. nov.; Ophidia; rattlesnake
