author(s)
K Shiny Sreedhar

abstract
Toxicological studies were conducted to assess the toxicity of the fertilizer, factamfos and its effect on gill, liver and kidney of the fish, Etroplus maculatus. Fish were exposed to asdifferent concentrations of factamfos to find out the median lethal concentration (LC₅₀). LC₅₀ was found to be 265 ppm. In chronic toxicity studies, fish having almost uniform size were exposed to sub lethal (26.5 ppm) concentration of factamfos along with a control for a period of 20 days. After the exposure time, the tissues, gill, liver and kidney, were excised, processed and stained in haematoxylin and eosin. Histological alterations of these tissues in different levels, such as, gill filament rupture, severe degeneration and more prominent fusion of lamellae; severe necrosis and hypertrophy in the liver tissues; fusion of renal corpuscles and renal tubule and glomerular expansion could be observed. It revealed that like pesticides, the fertilizer also causes destruction of various organs and thus adversely affects the fish population in the ecosystem.