Scanning electron microscopic observations of first- and third-stage larvae and adults of Angiostrongylus costaricensis.

The surfaces of larval and adult Angiostrongylus costaricensis, causative agent of human abdominal granuloma, were studied by the use of scanning electron microscopy. Cuticular annulations were clearly demonstrated on the surface of larvae and adults. Differences in the appearance of alae in larval stages and in the shape of the tail at different stages of development are described and illustrated. Several aspects of morphology previously unreported for this parasite are also described.