为揭示日本沼虾( Macrobrachium nipponense)对水体pH的适应性,分析了不同pH胁迫下日本沼虾在不同时段的存活率以及96 h后蜕壳率,免疫、肝功能相关酶活性的变化。结果显示, pH胁迫处理96 h时,不同pH处理组日本沼虾的存活率显著低于对照组,除pH 7．0组的蜕壳率与对照组差异不显著外,其余pH处理组蜕壳率显著高于对照组；暴露在弱酸性水( pH 6．0)、弱碱性水( pH 8．0)、碱性水( PH9．0)中的成活率不同,其中PH6．0组虾的成活率在36 h时显著低于PH8．0组,24 h时显著低于pH 9．0组； pH 5．0酸性处理组日本沼虾在试验期间存活率始终最低,上述结果表明日本沼虾对碱性水体的适应性强于酸性水体。比较不同pH值对日本沼虾肝功能相关酶活性的影响程度时发现,日本沼虾T-SOD、 ACP、 GOT、 T-AOC酶的耐受pH生态幅较窄, AKP酶的耐受pH生态幅较宽。通过96 h的pH值与相关酶回归分析得出,日本沼虾的最适pH值范围为7．3~7．6。%To evaluate the tolerance of oriental river prawn ( Macrobrachium nipponense) to water pH variations, the sur-vival rates of the oriental river prawn, at different water pH levels and time points after stress treatment, were examined. The molting rates of oriental river prawn, and the activities of immune-related and/or liver function enzymes at 96 h follow-ing treatment were also assayed. Results showed that, at 96 h following pH stress treatment, the survival rates of oriental river prawn at different water pH levels were significantly lower than control group. The molting rates at different water pH levels were significantly higher than control group, except for pH 7. 0 group. The prawn survival rate from moderately acid-ic water (pH 6. 0) was significantly lower than that from moderately alkaline water (pH 8. 0) at 36 h, and also than that from severely alkaline water (pH 9. 0) at 24 h. The lowest survival rate was always observed in severely acidic water (pH 5. 0) at each time point. These results indicated that oriental river prawn survived better under alkaline than under acidic water conditions. By comparing the effects of different pH levels on the activities of liver function enzymes, it was found that T-SOD, ACP, GOT, and T-AOC enzymes exhibited relatively wide pH range tolerance, while AKP enzyme dis-played relatively narrow range. The result of regression analysis between pH values and activities of those enzymes at 96 h showed that the optimum pH range for the prawn was between 7. 3 and 7. 6.
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