Ultrastructure of the alimentary tract of third-stage larvae of Litomosoides carinii.

The ultrastructural morphology of the alimentary tract of the third-stage larvae of Litomosoides carinii (Nematoda: Filarioidea) is described. The oesophagus possesses the characteristic tri-radiate lumen and is lined by cuticle. Teh lumen of the oesophagus is tightly occluded anteriorly by particulate material and posteriorly at the oesophagointestional junction. Three glands are present in the glandular region, one dorsal and two subventral. These glands contain secretory granules with similar morphological and staining properties. The lumen of the intestine is ill-defined without microvilli and apparently non-functional. It is likely that the larvae feed via the transcuticular route.