ABSTRACT

Third-stage larval spirurid nematodes, Physocephalus sexalatus, were found to be infecting three species of rattlesnakes, Crotalus spp., from southwestern Texas. These roundworms were encysted in granulomas of the stomach of a western diamondback rattlesnake, C. atrox, a mottled rock rattlesnake, C. lepidus lepidus, and a Mojave rattlesnake, C. scutulatus. We report detailed histopathological information on the infection in C. l. lepidus. This is the first time P. sexalatus has been reported from C. l. lepidus and C. scutulatus. In addition, an oligacanthorhychid acanthocephalan infected C. l. lepidus.