Gills consist of specialized structures including primary and secondary lamellae, chloride cells, epithelial cells, mucous cells, and venous sinuses, which are crucial for breathing and osmotic pressure management. The findings underscore substantial histological alterations caused by pollution exposure. Carassius auratus collected from ornamental fish shops in five different locations of Wasit Governorate, at a rate of four goldfish from each site. In addition, five water samples were collected from the same ponds from which the fish were obtained, the necessary chemical and physical analyses were conducted on them to determine the levels of pollutants in those ponds. The physicochemical analyses of the water revealed a clear, significant difference regarding the level of contamination in that water. On the other hand, histological results of the gills after they were stained with routine dye H here, we note moderate fibrosis with lamellae fusion, hyperplasia and vascular congestion.
Asawer Abd Al Jabbar (Fri,) studied this question.