Systematics of the genus Gnathostoma (Nematoda: Gnathostomatidae) in the Americas
To date, more than 20 species of the genus Gnathostoma have been described as parasites of mammals, 9 of them in the Americas. However, the taxonomic status of some of these species has been questioned. The main goal of this study is to clarify the validity of the American species included in the genus. In order to complete this objective, we analyze type and/or voucher specimens of all these species deposited in 6 scientific collections, through morphometric and ultrastructural studies. Based on diagnostic traits as host specificity, site of infection, body size, cuticular spines, presence of 1 or 2 bulges in the polar ends of eggs, as well as eggshell and caudal bursa morphology, we re-establish Gnathostoma socialis (Leidy, 1858) and confirm the validity of other 6 species: Gnathostoma turgidum Stossich, 1902, Gnathostoma americanum Travassos, 1925, Gnathostoma procyonis Chandler, 1942, Gnathostoma miyazakii Anderson, 1964, Gnathostoma binucleatum Almeyda-Artigas, 1991, and Gnathostoma lamothei Bertoni-Ruiz, Garcia-Prieto, Osorio-Sarabia and Leon-Regagnon, 2005. Gnathostoma didelphis Chandler, 1932 and Gnathostoma brasiliensis Ruiz, 1952 are considered synonyms of G. turgidum. Finally, based on a wide revision of specimens deposited in 6 American collections, we conclude that records of Gnathostoma spinigerum Owen, 1836 in the Americas are invalid.