污染水体中鱼体内三聚氰胺的累积及其在清洁水体中的消除

以吉富罗非鱼（Oreochromis niloticus）为受试动物,在室内用水族箱进行模拟养殖试验,设定污染水体中三聚氰胺初始浓度为0.2 g·L-1,考察罗非鱼在其中饲养1周期间体内三聚氰胺的累积情况。再将鱼转移至不含三聚氰胺的清洁水体中饲养1周,考察鱼体内三聚氰胺在其中的消除情况。结果表明,三聚氰胺能在鱼体内迅速富集,鱼肉及内脏中三聚氰胺的含量均与鱼在污染水体中暴露的时间成正相关。其中,鱼肉中三聚氰胺的浓度几乎成线性增大,拟合所得方程为y=5.598 8x＋12.897,相关系数为0.995 9。内脏对三聚氰胺的富集速率先快后慢,且其中三聚氰胺的浓度为鱼肉的2~3倍。在试验后期,鱼肉及内脏中三聚氰胺的浓度分别高达51.55 mg·kg-1和93.89 mg·kg-1,此时罗非鱼表现出明显的中毒迹象。将罗非鱼转移至清洁水体中养殖后,鱼肉及内脏中三聚氰胺的残留量均迅速下降,尤其是后者的消除速度甚快,一周后两者的浓度分别降至0.13 mg·kg-1和0.21 mg·kg-1。此时,罗非鱼中毒症状逐渐消失,活动趋向正常。

Accumulation of melamine in tilapia in melamine-polluted water and its elimination in clean water

The accumulation of melamine in GIFT tilapia in water containing melamine （0.2 g.L-1） was investigated for a week through laboratory experiments. Then the fishes were transferred to clean water and another 7-day trial was conducted to study the elimination of their residual melamine. The results showed that melamine could be easily enriched by tilapia, and the melamine concentration in its muscles or innards was enhanced rapidly with the increase of exposure time. The accumulated amount of melamine in the muscle rose almost linearly to the time, and the regression equation was y=5.598 8 x-1-12.897, with correlation coefficient of 0.995 9. It was also found that the bio-accumulation of melamine in the innards was very fast at first and then slowed down gradually, and the melamine concentration in the innards was 2-3 times higher than that in the muscles. At the end of the experiment, the melamine concentration in the innards and muscles of tilapia were as high as 51.55 mg＇kg-land 93.89 mg.kgq respectively, and the tilapia showed obvious toxicity symptom. However, after the fish were transferred to clean water, the melamine residues in the muscles and innards were decreased drastically, and their concentrations were less than 0.13 mg kg-1 and 0.21 mg.kg-1 respectively a week later. It was observed that after switching to clean water, tilapia＇s poisoning symptom disappeared gradually and its physical activity was towards normal.