Zn2＋对日本沼虾(Macrobrachium nipponensis)的急性致毒效应

ACUTE TOXIC EFFECTS OF ZINC ON FRESHWATER SHRIMP MACROBRACHIUM NIPPONENSIS

在水温(27.4±1.3)℃条件下,以体长(33.23±1.66)mm、体质量(0.7893±0.1518)g的日本沼虾为实验动物,采用静水停食法开展了Zn2+对日本沼虾的急性毒性实验,并以此为基础,测定了Zn2+不同质量浓度水平下日本沼虾的耗氧率与窒息点。结果表明:(1)Zn2+对日本沼虾的急性致死效应与其呼吸生理代谢受阻密切相关;(2)Zn2+对日本沼虾24h、48h、72h、96h的半致死质量浓度依次为1.493、0.844、0.643和0.464mg/L;(3)Zn2+对日本沼虾昼均、夜均和日均耗氧率均无显著影响的阈值为0.046mg/L,该值为Zn2+对日本沼虾急性毒性的安全质量浓度;(4)Zn2+对日本沼虾产生轻度胁迫和中度胁迫的质量浓度范围分别为0.046—0.064mg/L和0.064—0.082mg/L。

The acute toxicity experiment of zinc on freshwater shrimp （Macrobrachium nipponensis）, with （33.23±1.66）mm total length and （0.7893±0.1518）g weight, was carried out in static water without feeding at the water temperature （27.4±1.3）℃. Based on this experiment, the oxygen consumption rate and the suffocation point ofM. nipponensis exposed to different concentrations of zinc were measured. The result showed that there was a close relationship between the acute lethal effect of Zn2＋ and the inhibition of respiratory metabolism. The LC50 of Zn2＋ on shrimp at 24, 48, 72 and 96h were 1.493, 0.844, 0.643, and 0.464mg/L, respectively. The threshold value of zinc concentration that causes no significant difference in the average oxygen consumption and suffocation point ofM. nipponensis was 0.046mg/L, and this value was set as the safe concentration that zinc has no acute toxic effect on M. nipponensis. The mild stress range is from 0.046mg/L to 0.064mg/L and moderate stress range is from 0.064mg/L to 0.082mg/L for Zn2＋ on M. nipponensis.