[Morphology of III stage larvae of Angiostrongylus cantonensis in Pomacea canaliculata].

Objective: To observe the morphologic characteristics of III stage larvae of Angiostrongylus cantonensis from Pomacea canaliculata.

Methods: P. canaliculata, the intermediate host snail of A. cantonensis, was infected with I stage larvae of A. cantonensis in laboratory. After 61 days, III stage larvae of A. cantonensis were harvested from snail's lungs and muscle of head-foot, followed by HE stain to observe morphological characteristics.

Results: The whole body of III stage larva was curling with obtuse head. Its pharyngeal canal extends from the buccal hole on the top of the head to the intestines at the pharyngeal intestine joint place, with apex cauda and clear anal tube. The tegument of the III stage larva was eosin-stained, with a transparent sheath outside of tegument. Some of the larvae cauda showed in circular cylinder, and some larvae presented ventral gland with two very short uterine which used to be the feature only showed in early IV stage larva.

Conclusion: Morphologically characteristics of the III stage larvae is helpful to better understand the life-cycle and the control of A. cantonensis.