Parasitology, Harold W. Manter Laboratory of


Date of this Version


Document Type



Proc. Helminthol. Soc. Wash. 50(2), 1983, pp. 278-284


Copyright © The Helminthological Society of Washington


The nematode Heligmosomoides thomomyos sp. n. is described from the small intestine of Thomomys bulbivorus and T. bottae. This is the first report of Heligmosomoides from rodents of the family Geomyidae.

Nematodes of the genus Heligmosomoides Hall, 1916 occur most commonly in arvicolid rodents. Of the 26 known species of the genus, 11 have been recorded from Nearctic rodents (Rausch and Rausch, 1973). In North America, Heligmosomoides spp. have been recorded not only from voles, but also from cricetids and murids. Heligmosomoides spp. characteristically inhabit the small intestine or cecum of their host, where they usually are found tightly coiled around the intestinal or cecal villi (Durette-Desset, 1971).

Nematodes representing an undescribed species of Heligmosomoides were found by us in the small intestine of pocket gophers (Geomyidae) of two species, Thomomys bulbivorus (Richardson), from Benton County, Oregon, and T. bottae (Eydoux and Gervais), from Humboldt County, California (collected respectively by S.L.G. and D.P.J.). Rodents of the genus Thomomys have an extensive geographic range in central and western North America. Thomomys bulbivorus is endemic to the Willamette Valley of Oregon, and T. bottae occurs from southwestern Oregon southward to Arizona and northern Mexico (Hall and Kelson, 1959; Ingles, 1965).

It is the purpose of the present paper to describe this nematode, which is the first species of Heligmosomoides to be recorded from rodents of the family Geomyidae.