【摘要】 本文对钩棘单睾吸虫的第一中间螺蛳宿主自然感染情况进行调查，显示了一年中该虫尾蚴感染率随季节呈动态变化，10月份瘤拟黑螺感染率高达5.42％。各地瘤拟黑螺与纹沼螺平均感染率分别为2.45％（38／1548）与0.73％（20／2726），表明前者为本吸虫更为适宜的第一中间宿主。感染实验结果表明，该虫尾蚴侵染鱼类宿主后须经25d囊蚴发育完全成熟，而囊蚴感染终未宿主仅4d即可发育为成虫并产卵，其发育迅速为吸虫类所罕见。更多还原

【Abstract】 Results of natural infection of Haplorchis pumilio for cercariae in its first intermediate host showed that the infection rate varied in the different seasons. The infection rate of Melanoides tuberculata was found to be higher (5. 42% ) in October than that in other months. M. tuberculata and Parafossarulus striatulus were examined in different sites,with an average poslt1ve rate of 2. 45 T6 (38/1548) and 0. 73 % (20/2726) respectively. It is considered that M. tuberculata is more adaptability as the first intermediate host of H. pumilio than P.strtatulus. Ideal encysted metacercariae were found in the muscle of fresh-water fish after experimental infection with the cercariae for 25 days. The adult worm of H. pumilio developed qulckly after infection in its final host (dog),and parasite eggs could be found after infection for 4 days.更多还原