Studies on the male and female copulatory apparatus of Trichuris globulosa (Nematoda, Trichuridae)

The process of copulation in Trichuris globulosa (see Linstow, 1901) Ransom, 1911 has been studied using morphological, histological and scanning electron microscopical techniques (Keilley et al., 1973). The ventral coiling of the posterior part of the male body around the female is achieved by specialized muscles of the ventral body-wall. The single simple pointed spicule emerges with the everting cirrus and acquires a J-shape. The spicule may help in keeping apart the cuticular brim of the non-spiny noneversible part of the vagina during insemination. The cloacal tube is long with a detached internal cuticle which is eversible to the outside as a cirrus. Eversion is brought about by the protrusion of the spicule and contraction of the muscles of the spicule pouch. During eversion part of the proximal cloacal tube is also extruded and forms the globular part of the cirrus. The globular part is covered with spines, which may help in retaining the male and female in copula. The vagina is differentiated into the proximal vagina uterine and distal vagina vera. The vagina vera has a distal eversible spiny part and a proximal noneversible unarmed part. In Trichuris globulosa, the vagina vera is shorter than the spicule.