Scanning electron microscopy of Turgida turgida (Nematoda : Spiruroidea), parasite of the Virginia opossum, Didelphis virginiana, from southern California

Taxonomic characters for identification of Turgida turgida Rudolphi, 1819, a parasitic nematode of the Virginia opossum Didelphis virginiana, were stu died by scanning electron microscopy. The distinguishing feature of the cep halic end is the presence of numerous denticles, structures associated with the internal tooth, and 2 spongelike areas on the inner side of each pseud olabia. The posterior end of male T. turgida differs from that in other spe cies of Physalopteridae by the number of caudal papillae (22), truncated po stcloacal papilla, and patterns of ventrocaudal ornamentation.