黑斑蛙双睾吸虫的生活史研究

本文首次研究了黑斑蛙双睾吸虫的生活史。实验证明这种单殖吸虫的生活史具有两种不同的途径,即直接外生周期和直接内生周期。前一种发育途径为一般多盘吸虫所共有,后一种发育途径仅在少数多盘吸虫中存在。这两种发育途径的交替存在与其两栖动物宿主生态学有关,并且可能反映了这类多盘吸虫的一种种群调节机制。

ON THE LIFE CYCLE OF DIPLORCHIS NIGROMACULATUS

The life cycle of Diplorchis nigromaculatus was studied. There were two different pathways of the life history in the polystomatid monogenean. The first pattern was an external cycle, i.e. the egg hatched in the water after being expelled, and the swimming oncomiracidium, attached to the gill arch of the tadpole through the spriacle of the gill. As the metamorphosis of the tadpole was approaching, the post-larva left the branchial cavity and migrated to the skin of the host until it reached the urinary bladder by way of the cloaca. The second pattern was an internal cycle, as discovered by C. Combes et al. in some other polystomes, i.e. the egg could hatch directly in the urinary bladder and the larva settled immediately on its wall.This internal cycle was evidenced by the following facts: (1) High intensity of the mo-nogenean with lower incidence; (2) Coexistence of the worms at every stage of development inside the same bladder; (3) Coexistence of the two different types of the egg in the uterus of the same adult.The alternation of the two cycles appeared closely related to the ecology of the amphibian host and could be used to explain the population dynamics of the monogenean parasite.