Abstract: Objective To study the differences of the phenoloxidase （PO） relative activity among ribbed shelled Oncomelania hupensis， smooth shelled O. hupensis and Cipangopaludina chinensis. Methods The crude PO fluid was extracted from the soft tissue of the Oncomelania snail and C. chinensis by homogenation and centrifugation. The PO activity was detected with catechol as the substrate in the reaction systems. Results The PO relative activities in the ribbed shelled Oncomelania hupensis， smooth shelled O. hupensis and C. chinensis were （25.72 ± 2.27）， （14.56 ± 1.24） U/mL and （13.72 ± 1.06） U/mL. The PO relative activity in the smooth shelled O. hupensis was higher than that in the ribbed shelled O. hupensis （q = 21.46， P < 0.05） and C. chinensis （q = 12.00， P < 0.05）， while the difference between the PO relative activities of the latter two was not statistically significant （q = 1.62， P > 0.05）. Conclusion There is a difference in the relative PO activity between O. hupensis and C. chinensis，which may be related to the living environment of snails.

Key words: Oncomelania hupensis, Cipangopaludina chinensis, Phenoloxidase

摘要： 目的 比较湖北钉螺及中华圆田螺体内酚氧化酶活力差异。方法 以螺软体组织制备粗制酶液，以邻苯二酚为底物，测定肋壳钉螺、光壳钉螺和中华圆田螺体内酚氧化酶活力。结果 光壳钉螺、肋壳钉螺、中华圆田螺体内酚氧化酶活力值分别为（25.72 ± 2.27）、（14.56 ± 1.24） U/mL和（13.72 ± 1.06） U/mL，光壳钉螺体内酚氧化酶活力值高于肋壳钉螺（q = 21.46，P < 0.05）及中华圆田螺（q = 12.00，P < 0.05），中华圆田螺与肋壳钉螺体内酚氧化酶活力值差异无统计学意义（q = 1.62，P > 0.05）。结论 湖北钉螺及中华圆田螺体内酚氧化酶活力存在差异，可能与螺的生活环境有关。

关键词: 湖北钉螺, 中华圆田螺, 酚氧化酶