Morphological changes in the gills of Lophiosilurus alexandri exposed to un-ionized ammonia



The average lethal concentration of un-ionized ammonia (48-h LC50NH3) has been determined by the static assay for larvae (0.48 mg l−1) and alevins (0.92 mg l−1) of ‘pacamã’Lophiosilurus alexandri. Studies by light and scanning electron microscopes at the greatest concentration of NH3 (0.99 mg l−1 for larvae and 1.5 mg l−1 for alevins) have shown that the changes in the cells and branchial tissue were more intense in the alevins.