Vol. 3, Issue 7, Part A (2017)

Abstract
During the past development of Nano technology and the probably of its side effects on aquatic body organs, this study investigate the effect of nano silver administration on histology of gills in catfish Clarias bactracus following chronic exposure to sub lethal concentrations of silver nanoparticles. When fish were exposed silver nanoparticles size (10nm), (N10) 1/15^th of 96 h Lc 50 value for 10 and 20 days. In the gills, the epithelical cells as well as the pilaster cells showed signs of degeneration. The epithelial cells at places lost their cell walls. The secondary lamellae became swollened and the epithelial cells became hypertrophied after an exposure to of 0.10 mg 1^-1 of Silver nanoparticles for 10 days after 20 days of exposure the epithelial cells and basement membrane became further separated from pilaster cells. The secondary lamellae of the alternate side were more affected. The current findings indicate effect on Claraus batrachus chronic effect on Clarias batrachus; therefore preventing the entry of silver nano-materials into the aquatic environment would seem to be essential.