Abstract
Pollution of aquatic environment is a great concern worldwide. The teleostean kidney is one of the first organ to be affected by contaminants in water. The aim of this study is to assess histological changes of Oreochromis niloticus kidney collected from spring canals in Al-Hassa, Saudi Arabia. We report histological alterations in the kidney tissue of fish collected from three sites, namely Al-Jawhariya (site #1), Um-Sabah (site #2) and Al-Khadoud spring (site #3). The histopathological studies revealed relative differences in the severity of organ lesions among the three sites. The overall results showed that kidney architecture of fish samples was markedly disrupted. The major symptoms were dilation of the glomerular capillaries, reduction of Bowman's space, degeneration of tubular epithelium, tubule cast deposition, and accumulation of pigmented macrophages (i.e., melanomacrophages). The histological damage in the kidney of O. niloticus is an evidence of the poor environmental quality of these spring canals It appears that these wetland areas are still threatened by human activities and environmental degradation.