重金属混合液对罗非鱼嗅觉的毒性

The Toxicity of Metal-Mixed Solution on Olfactory of Fish(Tilapia sp.)

鱼类的嗅觉是一种重要的距离感受器,它能灵敏地感受周围环境的微妙变化。在鱼的摄食、集群、防御、繁殖、迁移等活动中发挥着重要的作用,是其赖以生存的重要感受器之一,也是人类不可多得的一种灵敏的生物学监测指标[柴敏娟等,1996]。水域中存在的重金属污染物往往不是单一种的,而是繁多的,这绪多的污染物对鱼类生存有没有影响,怎样影响鱼的生理活动?这方面国内研究不多。本文选择我省淡水渔业养殖常用品种罗非鱼(Tilapia sp.)为实验对象,用电生理方法,研究3种二价金属离子(Cu^(2+)、Zn^(2+)、Ca^(2+))相互混合对鱼类嗅电图(Electro-olfactogram,下简称EOG)的影响,并探讨其机制。

The toxicity of various metal-mixed solutions has been studied on the fosh olfactory receptors by electrophysiology method,and the mechaniam of toxicity has been discussed. The results indicate that: (1 )Under the condition of the epually Ca2 + concentration,the effects of inhibiting EOG response depend on the metallic ion concentrations of mixed solutions which respectively contain(Cu2+ +Ca2+) , (Zn2+ +Ca2+)and(Cu2++Zn2++ Ca2+ ). The higher the concentrations,the more obvious the inhibiting effects(2)Among the various metal-mixed solutions,the inhibiting effects of the solutions which contain Ca2+ are less than those of the solutions which contains no Ca2+. Especially, the effective LC50Values of the both ionic solutions which contain (Cu2+ + Ca2+) or (Zn2+ + Ca2+ ) are much higher than those of solutions which contain only Cu2+ or Zn2+. This fact shows that the toxicity of metal-mixed solutions which contain Ca2+ are obviously less than that of solutions which contain no Ca2+. (3)There is an antagonistic effect between Ca2+ and Cu2+ ,or Ca2+ and Zn2+ ,or Ca2+ and (Cu2++Zn2+) , which suggests that Ca2+ has a detoxify action. (4)The toxicity of(Cu2+ +Zn2+ )mixed solution is more than that of solution of solution which contains only Cu2+ or Zn2+. The interaction brtween Cu2+ and Zn2+ is syn-ergistic effect.