Changes in gill structure induced by BHC, lindane and endosulfan in the fresh-water teleost Puntius ticto (Ham.)

The effect of three organochlorinated pesticides on the gill structure of Puntius ticto, a freshwater teleost, was investigated. Fish exposed to sublethal concentrations of BHC (0.17 ppm), lindane (0.19 ppm) and endosulfan (0.20 ppm) were studied. The pesticides were detected qualitatively in the gill tissue by thin-layer chromatography (TLC). The results showed that they could be detected after 15 days' exposure, but not after 96 h exposure. Histopathological examination revealed several structural and functional changes in the gills. Exposure to BHC was followed by an inflammatory reaction and complete dystrophy of the lamellar structure of the gills. Lindane-treated fish showed disruption of the epithelial covering of the gills and excessive haemorrhage in the blood vessels. In exposure to endosulfan the gill lamellae shrank and became thinner.