Abamectin effects on rainbow trout (Oncorhynchus mykiss)

The effect of abamectin (ABM) on rainbow trout (Oncorhynchus mykiss) was studied. The acute toxicity of ABM on rainbow trout was established, following the target 58-h water bath exposure of ABM concentrations from 0.6 to 4.5 mu g/l, on the basis of which LD75 (4.0 mu g/l) was calculated. The histological changes in organs showed a direct toxicity of ABM for rainbow trout since degenerative changes in brain and kidney and-to a minor extent-in liver were established. The values of the ABM residues in fish muscle tissue with skin were proportional to the exposed concentrations of ABM.