Abstract: Objective　To compare the external morphological characteristics and movement patterns between Schistosoma japonicum and S. sinensis cercariae. Methods　S. japonicum and S. sinensis cercariae were heat⁃fixed, and well⁃extended cercariae, of 50 each species, were randomly selected for measurement of body length, body width, tail stem length, and tail fork length. The external morphological characteristics of S. japonicum and S. sinensis cercariae were compared. In addition, S. japonicum⁃infected Oncomelania snails and S. sinensis⁃infected Tricula snails were observed under a microscope and the movement patterns of S. japonicum and S. sinensis cercariae were compared. Results　The mean body length, body width, tail stem length, and tail fork length were (0.16 ± 0.01), (0.05 ± 0.01), (0.14 ± 0.01) mm and (0.06 ± 0.01) mm for S. japonicum cercariae, and (0.13 ± 0.01), (0.05 ± 0.01), (0.13 ± 0.01) mm and (0.06 ± 0.01) mm for S. sinensis cercariae, respectively, and there were significant differences in terms of cercaria body length (t = 14.583, P < 0.05) and tail stem length (t = 3.861, P < 0.05), while no significant differences were seen in terms of body width (t = 0.896, P > 0.05) or tail fork length (t = -0.454, P > 0.05). Microscopy revealed that the tails of both S. japonicum and S. sinensis cercariae swung from side to side and there was no significant difference in their movement pattern. Conclusion　S. sinensis and S. japonicum cercariae share highly similar external external morphological characteristics and movement patterns.

Key words: Schistosoma japonicum, Schistosoma sinensis, Cercaria, Oncomelania hupensis, Tricula, External morphology, Movement pattern

摘要： 目的　了解日本血吸虫和中华血吸虫尾蚴外部形态特征与运动方式差异。方法　对日本血吸虫和中华血吸虫尾蚴分别进行热固定，随机选取形态舒展较好的两种尾蚴各50条，测量其体长、体宽、尾干长、尾叉长，比较两种血吸虫尾蚴外部形态特征。对日本血吸虫感染钉螺和中华血吸虫感染拟钉螺压碎镜检，比较两种血吸虫尾蚴的运动方式。结果　日本血吸虫尾蚴平均体长、体宽、尾干长、尾叉长分别为（0.16 ± 0.01）、（0.05 ± 0.01）、（0.14 ± 0.01） mm和（0.06 ± 0.01） mm，中华血吸虫尾蚴平均体长、体宽、尾干长、尾叉长分别为（0.13 ± 0.01）、（0.05 ± 0.01）、（0.13 ± 0.01） mm和（0.06 ± 0.01） mm，两种血吸虫尾蚴体长（t = 14.583，P < 0.05）、尾干长（t = 3.861，P < 0.05）差异均有统计学意义，而体宽（t = 0.896，P > 0.05）、尾叉长（t = −0.454，P > 0.05）差异均无统计学意义。镜下观察发现，两种血吸虫尾蚴运动方式均表现为尾部左右摆动，无明显差异。结论　中华血吸虫与日本血吸虫尾蚴外部形态及运动方式相似度较高。

关键词: 日本血吸虫, 中华血吸虫, 尾蚴, 钉螺, 拟钉螺, 外部形态, 运动方式