Loker E S
J Parasitol. 1978 Dec;64(6):977-85.
Schistosomatium douthitti miracidia are ingested by Lymnaea catascopium snails and penetrate the host's esophageal wall. Mother sporocysts develop adjacent to the esophagus and salivary glands. The increase greatly in size, become irregular in shape, and contain daughter sporocysts by 8 days. Development of daughter sporocysts is synchronous; most are released from mother sporocysts 16--20 days postexposure. Mother sporocysts then collapse, but may persist for the life of the infected snail. Some daughter sporocysts travel to the digestive gland via the arterial system; others traverse the connective tissue separating cephalopedal and visceral sinuses to reach the digestive gland. Cercarial embryo production begins while daughter sporocysts are still within mother sporocysts, and may continue for over 400 days. Once released from daughter sporocysts, cercariae move from the visceral sinus to the visceral vein and are carried into the mantle where they rupture the ventral mantle epithelium and escape from the molluscan host.
杜氏血吸虫毛蚴被猫眼豆螺吞食后穿透宿主的食管壁。母胞蚴在食管和唾液腺附近发育。到8天时，它们的体积大幅增大，形状变得不规则，并含有子胞蚴。子胞蚴的发育是同步的；大多数在暴露后16 - 20天从母胞蚴中释放出来。然后母胞蚴会萎缩，但可能在受感染螺的生命周期内持续存在。一些子胞蚴通过动脉系统到达消化腺；其他子胞蚴穿过分隔头足部和内脏窦的结缔组织到达消化腺。尾蚴胚胎的产生在子胞蚴仍在母胞蚴内时就开始了，并且可能持续400多天。尾蚴一旦从子胞蚴中释放出来，就从内脏窦移动到内脏静脉，并被带到外套膜，在那里它们会破裂腹侧外套膜上皮并从软体动物宿主中逸出。
