Research has provided evidence to suggest that adult, male mammals will have greater parasite frequency than juvenile, female mammals (4, 6).  Virginia opossums (Didelphis virginiana) are located throughout most of North America and have been the focus of many parasite studies.  In particular, there are 2 common nematodes that parasitize the digestive tract of the Virginia opossum: Physaloptera turgida and Cruzia americana (2, 3, 4, and 5).  The purpose of this study was to determine if there is a correlation between the age and gend4er of the host opossum, and the number of nematodes residing in these animals.