Influence of potassium permanganate on chronic toxicity of cadmium to common carp, Cyprinus carpio, and aquatic ecosystem

Abstract

Common carp Cyprinus carpio was chronically exposed to cadmium (2.5 mgL^‐1) and combined treatment of cadmium and KMnO₄ (1 mgL^‐1) for 90d in outdoor artificial enclosures. Although total and filtrable (dissolved) cadmium of water gradually decreased during the experiment whole body concentration of cadmium in common carp progressively increased in both treatments. Combination of KMnO₄ with cadmium marginally reduced the accumulation of cadmium during the initial periods (30 d) but failed to produce any impact on accumulation at the end of experiment (90 d). Cadmium treatment alone did not reduce the length and weight of fish, but there was abnormality in the length weight relationship. KMnO₄ alone and in combination with cadmium significantly reduced the length, weight and yield of fish. Limnological parameters were not affected by KMnO₄ alone, but combined treatment of Cd and KMnO₄ reduced the zooplankton and phytoplankton population, primary productivity of water and NPP/CR ratio. Judicious use of KMnO₄ in aquaculture to avoid toxic interaction with cadmium has been recommended.

Keywords:

• Cadmium
• potassium permanganate
• Cyprinus carpio
• toxicity
• accumulation