Effect of lead on gill and liver of blue spotted ray (Dasyatis kuhlii)

The aim of study was to analyze the effect of lead nitrate Pb(NO3)2 on gill and liver of blue spotted ray Dasyatis kuhlii using a histological observation. The rays were placed in five tanks filled by seawater with three fishes for each tank. Blue spotted rays, Dasyatis kuhlii were treated for 12 days by using different concentrations of lead nitrate (Pb(NO3)2), that is, 0 ppm as control (treatment A), 0.2 ppm (treatment B), 0.5 (treatment C), 0.9 ppm (treatment D) and 1.8 ppm (treatment E). The rays were placed in the tanks until all fishes exposed to Pb (treatments B to E) were dead. Results of the study show that Pb(NO3)2 exposure altered the gill and liver microscopic structure. Gill lamella alterations were found on hypertrophy, hyperplasia, club shaped, necrosis and formed bunch texture. Liver alterations included cloudy swelling, atrophy, necrosis, vacuolar degeneration and fatty degeneration. Death time of blue spotted ray became shorter when lead nitrate Pb(NO3)2 concentration increased.