Histopathology of lambda-cyhalothrin on tissues (gill, kidney, liver and intestine) of Cirrhinus mrigala

The histopathology of lambda-cyhalothrin, a synthetic pyrethroid pesticide, on the gill, liver, intestine and kidney tissues in fish, mrigal (Cirrhinus mrigala), which is one of Indian major carp species were determined by light microscopy. The fish were experimentally exposed to sub-lethal concentrations (0.3 ppb and 0.6 ppb) of lambda-cyhalothrin for 10 days. Tissues were normal in the control group. Epithelial hyperplasia, aneurism, epithelial necrosis, desquamation, epithelial lifting, oedema, shortening of secondary lamellae and lamellar fusion were observed in gill tissues exposed to lambda-cyhalothrin. Necrosis of tubular epithelium, cloudy swelling of epithelial cells of renal tubules, narrowing of the tubular lumen, contraction of the glomerulus and expansion of space inside the Bowman's capsule were observed in the kidney tissues of fish after exposure. Hepatic lesions in fish exposed to lambda-cyhalothrin were characterized by hypertrophy of hepatocytes, cloudy degeneration, congestion, karyolysis, karyohexis, dilatation of sinusoids and focal necrosis. The intestinal lesions included infiltration of eosinophils into the lamina propria and atrophy of epithelial cells. The present study proves its toxic potential in terms of the damages induced by lambda-cyhalothrin in organ level. In natural condition lambda-cyhalothrin will be less than the present study, but continuous usage of the pesticide might lead to the concentration that was used in the experimental condition. (C) 2007 Published by Elsevier B.V.