Toxocara canis: Ultrastructural aspects of larval moulting in the maturing eggs

摘要: The morphology of the surface Toxocara canis larvae, developing in eggs to reach infectivity, has been studied for first time at an electron microscopical level. In most 11-day and some 15-day eggs, larvae are surrounded by two shed cuticles. outer cuticle is composed layers. inner second much thicker than one. presence both cuticles indicates that larva undergone developmental stages maturing egg. one electron-dense This cuticular sheath identical with described cuticle, except its apparently reduced thickness. infective inside 30-day enveloped sheath, derived from moulted consisting only a single layer. findings discussed respect data concerning moulting process other nematode species.