Effects of Exposure to Bordeaux Mixture on Histological and Ultra Structural Features of Gills of Freshwater Fish Channa Punctatus (Bloch)

Bordeaux mixture acts as an effective fungicide because of the copper ions (Cu2+) of the mixture. Sub lethal concentration of Bordeaux mixture was investigated with fresh water teleost fish Channa punctatus. The present study deals with the deleterious effects of copper ions present in 13.06ppm Bordeaux mixture at the ultra structural levels of the gills of Channa punctatus (1/10th of LC 50 96 hrs). The gill histology was studied under light and scanning electron microscopy. Bordeaux mixture is having the capacity to make deleterious pathological changes in gills of fishes. The major changes observed were a distortion in the shape of secondary lamellae, epithelial hyperplasia, lamellar fusion, epithelial lifting, and epithelial necrosis of secondary lamellae. Fusion of secondary lamellae, shrinked or curved lamellae and vacuolization at the tip of the primary gill lamellae were the observed as characteristic feature of the pesticide exposed fish. The severity of the lesions was found to be increased with increase in exposure period.