Parafossarulus striatulus, Pseudorasbora parva and brood ducks are involved in the lifecycle of Metorchis orientalis. Natural nidi of M.orientalis are confirmed in Huaihe River Basin.

• 本文报道东方次睾吸虫可在纹沼螺、麦穗鱼和雏鸭体内完成生活史。淮河水系是东方次睾吸虫的自然疫源地。