Ultrastructure of the contact surfaces of Passalurus ambiguus (Rudolphi, 1819) (Nematoda)

The ultrastructure of the contact surfaces (integument and intestinal wall) of the nematode Passalurus ambiguus has been studied. The integument is composed according to the scheme common for all nematodes and includes a cuticle, hypodermis and a muscular layer. The specificity is with regard to the epicuticle, the different number of the cuticular sublayers in the anterior, central and the posterior parts of the worm body and the absence of a basal cuticular membrane. The intestinal wall consists of epithelial cells with microvilli. The ultrastructural characteristics of both contact surfaces indicate their main functions--absorption, secretion, transport, protection, movement, etc.