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

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