A study on behavioural responses and haematological effects of synthetic pyrethroid deltamethrin on fresh water teleost Channa punctatus (Bloch)

Abstract

Deltamethrin is a synthetic pyrethroid Pesticide widely used in agriculture. Pesticides in agricultural runoff can adversely affect any aquatic ecosystem and be detrimental to the aquatic fauna. Fishes are known to be widely affected by the toxic effects of these harmful chemicals, of which deltamethrin can be regarded as the most potent one. In the present study, the effect of deltamethrin on some behavioural and haematological parameters of the freshwater teleost Channa punctatus was investigated. Experimental fish were exposed to 0.075 mg/L and 0.15 mg/L sub-lethal concentrations of deltamethrin (LC₅₀- 0.5 mg/L) for 7 consecutive days. After 7 days of exposure, the alternation in various behavioural responses and haematological effects on fish was evaluated. The study revealed that Deltamethrin has toxic effects on behavioural as well as haematological aspects of Channa punctatus. The treated fish showed an increased number of surfacing and opercular movements, fast swimming, increased mucous secretion, and jumping to get rid of the treated water. Significant decrease in Red Blood Cells (RBCs) count, and Haemoglobin (Hb) concentration was observed. An increased number of White blood cells (WBC) in comparison with the control was also observed in the treated groups. From this present investigation, it can be substantiated that deltamethrin induces diverse negative impacts on fish.