Scanning electron microscopic observations of adult Baylisascaris procyonis (Nematoda).

The scanning electron microscope was used to illustrate the microtopographic features of the caudal end of adult male Baylisascaris procyonis. The male tail was relatively long, smoothly attenuated and often had a small button-like or mucronate termination. The preanal papillae were situated ventrally in two slightly divergent and somewhat irregularly spaced rows. Anterior and posterior to the anus were two slightly raised roughened patches consisting of several rows of small spines. Just anterior to the anus along the outer margin of the preanal roughened patch was a large double medioventral papilla. There were five pairs of postanal papillae with the first pair just posterior to the anus being double while the remaining four pairs were more closely associated in a group near the tail end. The second pair were also double papillae; however, in a few specimens they were not fused and appeared as two single closely associated papillae. The last three pairs of papillae were single. The fourth pair of caudal papillae were the phasmids and in the center of each was a ringed pore-like opening. The spicules of the male had a highly sculptured surface with a pincher-like terminal end.