The ultrastructure of the cuticle of the nematode Syphacia obvelata (Rudolphi, 1802). IV. The cuticle associated with the female excretory pore, vulva, and vagina vera.

Abstract

The cuticle forming the excretory pore complex and the vulva and vagina vera in female Syphacia obvelata is formed by body wall cuticle. The nature of the cuticle surrounding the excretory pore and forming the bladder, and tile absence of a muscular system to control the complex suggest that internal pressure (probably hydrostatic) is the generating force for fluid expulsion. The lumens of the vulva and vagina vera are lined by and continuous with the cortical zone of the body wall cuticle. The lumens of both the vulva and vagina vera are tetraradiate. The arrangement of the cuticle at the proximal end of the vagina vera allows for a mechanical means of ejecting eggs (the functional ovijector). The initial force to move eggs up to the ovijector is from the muscles surrounding the vagina vera.