Relationship of secreted mucus to copper and acid toxicity in rainbow trout [Salmo gairdneri]

Experiments have been carried out to determine the effect of lethal concentrations of copper and hydrogen ion concentration on the secretion of mucus by rainbow trout (Salmo gairdneri), and to study the effect of changes in pH value on the ability of the mucus to bind copper. It was shown that exposure to acid conditions caused a considerable increase in the rate of mucus excretion, but this effect was not observed when the fish were exposed to copper. The ability of mucus to chelate copper was confirmed.