Histopathological alterations in the gills of <i>Labeo</i> <i>rohita </i> (Hamilton-Buchanan) due to Lead toxicity

Abstract

Lead is an industrially important heavy metal used in manufacturing paints, batteries, explosives, pottery and other important products of daily life. On the other hand, it is the most damaging element for aquatic fauna especially fish as it accumulates in the body of organism and have low rate of elimination. The present paper emphasizes on the histopathological effects of different sub-lethal doses of lead nitrate on the gills of a commonly consumed freshwater fish Rohu, <i>Labeo</i> <i>rohita</i>. After 15, 30, 45 and 60 days of exposure, gill tissues were dissected and routine histological processes were done. No changes were seen in the gills of the control fingerlings. The histopathological changes such as cellular hypertrophy, hyperplasia, vacuolation, epithelial lifting, shortening, curling and abnormal elongation of the secondary lamellae, fusion of adjacent lamellae, telangiectasis, blood congestion, interstitial edema, necrosis, lamellar aneurysm, architectural distortion and degeneration of gills were observed in the gills of the treated fingerlings. The extent of damage of gill tissue was proportionate with the increased dosage and duration of lead nitrate exposure.