The Helminth Fauna of Chile. X. A New Species of Whipworm from a Chilean Rodent

Abstract

Trichuris fulvi n. sp. is described from a Chilean rodent Ctenomys fulvus phillipiensis. The new species differs primarily from T. bradleyi and T. chilensis, two other species described from rodents in Chile, primarily in the presence of a distinct spicular sac. The nematode genus Trichuris was proposed by Roederer in 1791 for whipworms occurring in humans; i.e., Trichuris trichiura (Linnaeus, 1771). Subsequently, most terrestrial host groups have been shown to harbor one or more species of the genus. The diversity of species in cricetid and heteromyid rodents was pointed out by Chandler (1945, 1946), and Tiner (1950) presented a key to eight trichurid species occurring in rodents and lagomorphs of North America. In Chile, some of the whipworms occurring in rodents of this geographic region appear not only to be new species, but may represent a new subgenus of Trichuris (see Babero et al., 1975, 1976). MATERIALS AND METHODS Through the courtesy of Mr. Milton Gallardo, Austral University of Chile, who was working on the systematics of the host group, the writers were provided with four living specimens of Ctenomys fulvus phillipiensis, obtained from San Pedro de Atacama (Province of Tarapaca) in northern Chile. From these host specimens, a total of two male and six female trichurids were collected from the caecum. The worms were fixed in 70% ethyl alcohol and later cleared for study in lactophenol. Comparative anatomical studies of the Chilean worms with descriptions and available specimens of other species of Trichuris from rodents showed our material to represent a new species. In the description that follows, measurements, based upon all specimens collected, are in millimeters (mm) and averages are given in parentheses.