The tolerance to air exposure and freshwater immersion was studied to study the optimum transportation time and stocking way in both juvenile and adult clams Mactra chinensis and M. veneriformis. The results showed that: 1) Both juveniles and adults of two clams had the significantly linear increase in mortality with the exposure period prolonging( P<0.05). At 25 ℃ , both juveniles showed LT90 of 26.4 h, LT50 of 20.4 h and LT10 of 14.4 h, in Mactra chinensis and LT90 of 29. 2, LT50 of 21. 9, and LT10 of 14. 6 h in M. veneriformis. The T90, LT50 and LT10 of both adults were 53. 2, 35. 8 , 18. 3 h and 124. 6, 95. 7, 66. 8 h at 15 ℃. 2) With the immersion period prolonging, the mortality rate of both Mactra chinensis and Mactra veneriformis was foundn to be increased linearly (P< 0.05 ); The LT90, LT50 and LT10 of both juveniles were 9.0, 6.6, 4.2 h and 15.3, 10.8, 6.4 h; The LT90, LT50, and LT10 of both adults were 29.4, 17.0, 4.6 h and 52.3, 28. 9, 5.6 h, respectively. 3) In general, M. veneriformis ( both juveniles and adults) showed stronger tolerance to air exposure and freshwater immersion than M. chinensis did.%为确定中国蛤蜊Mactra chinensis和四角蛤蜊Mactra veneriformis的最佳运输时间及放养方式,在实验室条件下分别进行了其稚贝与成贝对干露和淡水浸泡的耐受性研究.结果表明:1)在试验范围内,中国蛤蜊和四角蛤蜊的死亡率随干露时间的延长呈直线增加(P＜0.05)；气温为25℃时,中国蛤蜊稚贝耐干露的LT90、LT50和LT10依次为26.4、20.4、14.4 h,四角蛤蜊稚贝的依次为29.2、21.9、14.6 h；气温为15℃时,中国蛤蜊成贝耐干露的LT90、LT50和LT10依次为53.2、35.8、18.3 h,四角蛤蜊成贝的依次为124.6、95.7、66.8 h.2)在试验范围内,中国蛤蜊和四角蛤蜊的死亡率随淡水浸泡时间的延长呈直线增加(P＜0.05)；中国蛤蜊稚贝耐淡水浸泡的LT90、LT50和LT10依次为9.0、6.6、4.2h,四角蛤蜊稚贝的依次 为15.3、10.8、6.4h;中国蛤蜊成贝耐淡水浸泡的LT90、LT50和LT10依次为29.4、17.0、4.6h,四角蛤蜊成贝的依次为52.3、28.9、5.6h.本研究表明,四角蛤蜊耐干露和淡水浸泡能力总体上要强于中国蛤蜊.
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